| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 1 | //! Rust AST -> Nim source. |
| 2 | //! |
| 3 | //! The governing rule is in DESIGN.md and it shapes every function here: |
| 4 | //! anything whose Rust semantics cannot be reproduced exactly in Nim returns |
| 5 | //! `Err` with a reason. Nothing is emitted on a guess. Where a construct maps |
| 6 | //! one-to-one (signed `shr`, unsigned wrapping, truncating `div`/`mod`) the |
| 7 | //! mapping is direct and there is a comment saying why that is safe. |
| 8 | |
| 9 | use crate::fmt; |
| 10 | use crate::ty::{self, Nim}; |
| 11 | use std::collections::HashMap; |
| 12 | use syn::{ |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 13 | BinOp, Expr, FnArg, GenericArgument, Item, Lit, Local, Pat, ReturnType, Stmt, UnOp, |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 14 | }; |
| 15 | |
| 16 | // --------------------------------------------------------------- vocabulary |
| 17 | |
| 18 | /// Nim keywords. Rust code may legally use any of these as an identifier. |
| 19 | const NIM_KEYWORDS: &[&str] = &[ |
| 20 | "addr", "and", "as", "asm", "bind", "block", "break", "case", "cast", |
| 21 | "concept", "const", "continue", "converter", "defer", "discard", "distinct", |
| 22 | "div", "do", "elif", "else", "end", "enum", "except", "export", "finally", |
| 23 | "for", "from", "func", "if", "import", "in", "include", "interface", "is", |
| 24 | "isnot", "iterator", "let", "macro", "method", "mixin", "mod", "nil", "not", |
| 25 | "notin", "object", "of", "or", "out", "proc", "ptr", "raise", "ref", |
| 26 | "return", "shl", "shr", "static", "template", "try", "tuple", "type", |
| 27 | "using", "var", "when", "while", "xor", "result", "echo", |
| 28 | ]; |
| 29 | |
| 30 | fn ident(name: &str) -> String { |
| 31 | if NIM_KEYWORDS.contains(&name) { |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 32 | return format!("{name}_r"); |
| 33 | } |
| 34 | // Nim identifiers may not begin with an underscore, and may not contain |
| 35 | // two in a row. Rust uses both freely (`_unused`, `__private`). |
| 36 | let mut out = String::new(); |
| 37 | let mut last_us = false; |
| 38 | for (i, c) in name.chars().enumerate() { |
| 39 | if c == '_' { |
| 40 | if i == 0 { |
| 41 | out.push('u'); |
| 42 | out.push('_'); |
| 43 | last_us = true; |
| 44 | continue; |
| 45 | } |
| 46 | if last_us { |
| 47 | continue; |
| 48 | } |
| 49 | last_us = true; |
| 50 | out.push('_'); |
| 51 | } else { |
| 52 | last_us = false; |
| 53 | out.push(c); |
| 54 | } |
| 55 | } |
| 56 | if out.ends_with('_') { |
| 57 | out.push('x'); |
| 58 | } |
| 59 | out |
| 60 | } |
| 61 | |
| 62 | /// A `for`-loop source, resolved from a chain of iterator adaptors. |
| 63 | /// |
| 64 | /// Rust's slice iterators are lazy and compose; Nim's `for` is over one |
| 65 | /// sequence. So a chain is resolved into this shape and then emitted as a |
| 66 | /// single index loop, with each binding becoming an *lvalue* into the original |
| 67 | /// container. That is what makes `*dst = v` through `iter_mut()` write back to |
| 68 | /// the caller's slice rather than to a copy. |
| 69 | #[derive(Clone, Debug)] |
| 70 | enum Iter { |
| 71 | /// `a..b` / `a..=b`. |
| 72 | Range { lo: String, hi: String, closed: bool, ty: Option<Nim> }, |
| 73 | /// `for x in a`, `a.iter()`, `a.iter_mut()`. `off`/`len` let the same |
| 74 | /// shape cover a subslice view. `mutable` only affects whether the binding |
| 75 | /// may be assigned through. |
| 76 | Elems { code: String, off: String, len: String, elem: Option<Nim>, mutable: bool }, |
| 77 | /// `a.chunks_exact(k)` / `chunks_exact_mut(k)`: the binding is a window of |
| 78 | /// `k` elements starting at `k * i`. |
| Add closures and unsafe; base16ct's lower.rs and upper.rs go through 0a375d8 nandithebull 9h ago | 79 | Chunks { code: String, base: String, len: String, k: String, elem: Option<Nim>, mutable: bool }, |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 80 | /// `a.windows(k)`: like `Chunks` but advancing one element at a time. |
| Add closures and unsafe; base16ct's lower.rs and upper.rs go through 0a375d8 nandithebull 9h ago | 81 | Windows { code: String, base: String, len: String, k: String, elem: Option<Nim> }, |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 82 | /// `.enumerate()` — the index is the first half of the pair. |
| 83 | Enumerate(Box<Iter>), |
| 84 | /// `.zip(other)` — stops at the shorter, as Rust's does. |
| 85 | Zip(Box<Iter>, Box<Iter>), |
| 86 | } |
| 87 | |
| 88 | impl Iter { |
| 89 | /// The number of iterations, as a Nim expression in terms of the loop's |
| 90 | /// own containers. |
| 91 | fn len(&self) -> String { |
| 92 | match self { |
| 93 | Iter::Range { lo, hi, closed, .. } => { |
| 94 | let n = format!("(int({hi}) - int({lo}))"); |
| 95 | if *closed { format!("({n} + 1)") } else { n } |
| 96 | } |
| 97 | Iter::Elems { len, .. } => len.clone(), |
| Add closures and unsafe; base16ct's lower.rs and upper.rs go through 0a375d8 nandithebull 9h ago | 98 | Iter::Chunks { k, len, .. } => format!("({} div int({}))", len, k), |
| 99 | Iter::Windows { len, k, .. } => format!("(max(0, {} - int({}) + 1))", len, k), |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 100 | Iter::Enumerate(i) => i.len(), |
| 101 | Iter::Zip(a, b) => format!("min({}, {})", a.len(), b.len()), |
| 102 | } |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 103 | } |
| 104 | } |
| 105 | |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 106 | /// How a `for`-loop pattern name refers back into the container it came from. |
| 107 | #[derive(Clone, Debug)] |
| 108 | enum Alias { |
| 109 | /// The name stands for this Nim lvalue expression. |
| 110 | Value { code: String, ty: Option<Nim> }, |
| 111 | /// The name stands for a window: `code[off .. off + len - 1]`. |
| 112 | Window { code: String, off: String, len: String, elem: Option<Nim> }, |
| Transpile a second crate, adler2, to test whether any of this generalises 5fdd5be nandithebull 8h ago | 113 | /// The name stands for an iterator that has not been consumed yet, as in |
| 114 | /// `let it = xs.chunks_exact(k);`. Rust's iterators are values; ours are |
| 115 | /// resolved chains, so the chain is carried until a `for` consumes it. |
| 116 | Iterator(Box<Iter>), |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 117 | } |
| 118 | |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 119 | /// A lowered expression: its Nim text, and its type where we know it. |
| 120 | /// |
| 121 | /// The type is not decoration. Nim needs it to pick `div` over `/`, to size a |
| 122 | /// `cast`, and to annotate every binding so that Nim's own type checker |
| 123 | /// catches a mistake in this file rather than letting it through as output |
| 124 | /// that runs and is wrong. |
| 125 | #[derive(Clone, Debug)] |
| 126 | struct Val { |
| 127 | code: String, |
| 128 | ty: Option<Nim>, |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 129 | /// Set when the value *is* a slice view rather than a Nim value: binding |
| 130 | /// it introduces an alias, not a copy. |
| 131 | window: Option<Alias>, |
| 132 | /// For `get`/`get_mut`: the condition under which the `Option` is `Some`, |
| 133 | /// carried until an `ok_or`/`?` or an `unwrap` consumes it. Nim's view |
| 134 | /// types cannot live inside an object, so an `Option` of a view has no |
| 135 | /// runtime representation -- it is tracked here instead. |
| 136 | guard: Option<String>, |
| 137 | /// The error an `ok_or` attached to that guard. |
| 138 | guard_err: Option<String>, |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 139 | } |
| 140 | |
| 141 | impl Val { |
| 142 | fn new(code: impl Into<String>, ty: Option<Nim>) -> Self { |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 143 | Val { code: code.into(), ty, window: None, guard: None, guard_err: None } |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 144 | } |
| 145 | fn untyped(code: impl Into<String>) -> Self { |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 146 | Val::new(code, None) |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 147 | } |
| 148 | } |
| 149 | |
| 150 | struct Sig { |
| 151 | params: Vec<Nim>, |
| 152 | ret: Nim, |
| Add generics; transpile the part of cosmic-theme that is reachable ff34e1b nandithebull 7h ago | 153 | /// Type parameters this signature is generic in, so a call site can bind |
| 154 | /// them from its argument types. |
| 155 | generics: Vec<String>, |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 156 | } |
| 157 | |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 158 | /// One variant of a Rust enum. |
| 159 | #[derive(Clone)] |
| 160 | struct Variant { |
| 161 | name: String, |
| Lower the `log` facade, and add explicit enum discriminants 12c0a01 nandithebull 6h ago | 162 | /// `Error = 1` — Nim enums take explicit ordinals too, so the value is |
| 163 | /// preserved rather than the variant being renumbered. |
| 164 | discriminant: Option<String>, |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 165 | /// `(nim field name, type)`. Empty for a unit variant. Tuple variants get |
| 166 | /// `f0`, `f1`, ...; every field is prefixed with the variant name because |
| 167 | /// Nim requires the branches of a variant object to have distinct fields. |
| 168 | fields: Vec<(String, Nim)>, |
| 169 | } |
| 170 | |
| 171 | #[derive(Clone)] |
| 172 | struct EnumDef { |
| 173 | name: String, |
| 174 | /// True when every variant is a unit variant, which Nim represents as a |
| 175 | /// plain `enum` rather than an object variant. |
| 176 | simple: bool, |
| 177 | variants: Vec<Variant>, |
| 178 | } |
| 179 | |
| 180 | impl EnumDef { |
| 181 | fn kind_ident(&self, v: &str) -> String { |
| 182 | format!("k{}{}", self.name, v) |
| 183 | } |
| 184 | fn ctor_ident(&self, v: &str) -> String { |
| 185 | format!("{}{}", self.name, v) |
| 186 | } |
| 187 | fn get(&self, v: &str) -> Option<&Variant> { |
| 188 | self.variants.iter().find(|x| x.name == v) |
| 189 | } |
| 190 | } |
| 191 | |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 192 | pub struct Lowerer { |
| 193 | out: String, |
| 194 | indent: usize, |
| 195 | scopes: Vec<HashMap<String, Nim>>, |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 196 | /// Names introduced by a `for` pattern that stand for an lvalue or a |
| 197 | /// window into a container, rather than for a variable of their own. |
| 198 | alias_scopes: Vec<HashMap<String, Alias>>, |
| Add closures and unsafe; base16ct's lower.rs and upper.rs go through 0a375d8 nandithebull 9h ago | 199 | /// `(module, name) -> signature`. Rust keeps `lower::decode` and |
| 200 | /// `mixed::decode` apart by module; flattening into one Nim module would |
| 201 | /// merge them, so the module is part of the key and of the emitted name. |
| 202 | fns: HashMap<(String, String), Sig>, |
| 203 | /// Module being lowered: the file stem, or empty for the crate root. |
| 204 | cur_mod: String, |
| Transpile a second crate, adler2, to test whether any of this generalises 5fdd5be nandithebull 8h ago | 205 | /// The type of the `impl` block being lowered, which `Self` names. |
| 206 | self_ty: Option<Nim>, |
| Add generics; transpile the part of cosmic-theme that is reachable ff34e1b nandithebull 7h ago | 207 | /// Type parameters of the enclosing `impl`, which its methods share. |
| 208 | impl_generics: Vec<String>, |
| 209 | /// Type parameters of the proc being lowered, impl's included. |
| 210 | fn_generics: Vec<String>, |
| 211 | /// Type parameters declared by each generic struct or enum. |
| 212 | type_generics: HashMap<String, Vec<String>>, |
| Add associated types and consts, and test whether the blocker stack bottoms out 8354895 nandithebull 7h ago | 213 | /// `(type, name) -> type` for `type Item = ..;` inside an `impl`. Rust |
| 214 | /// writes those as `Self::Item`, which has to resolve before any |
| 215 | /// signature mentioning it is mapped. |
| 216 | assoc: HashMap<(String, String), Nim>, |
| 217 | /// `(type, name) -> (nim name, type)` for `const` items inside an `impl`. |
| 218 | assoc_consts: HashMap<(String, String), (String, Nim)>, |
| Lower `extern "C"` blocks to Nim importc; do not transpile libc 7db7991 nandithebull 6h ago | 219 | /// Symbols declared by an `extern "C"` block. |
| 220 | foreign: std::collections::HashSet<String>, |
| 221 | /// Const-qualified C pointer aliases already declared. |
| 222 | const_ptrs: std::collections::HashSet<String>, |
| Expand `macro_rules!` rather than translating it to a Nim template 04eb29f nandithebull 6h ago | 223 | /// `macro_rules!` definitions we can expand, and the reasons for those we |
| 224 | /// cannot, so a call site can say *why* rather than "unknown macro". |
| 225 | mrules: HashMap<String, crate::mrules::MacroDef>, |
| 226 | mrules_bad: HashMap<String, String>, |
| Expand multi-rule and recursive macro_rules d459281 nandithebull 5h ago | 227 | macro_depth: usize, |
| Lower `bitflags!` directly, checked against the real crate af6e50f nandithebull 7h ago | 228 | /// Types declared by a `bitflags!` invocation. |
| 229 | bitflags: std::collections::HashSet<String>, |
| 230 | /// `(type, flag) -> nim const name`. |
| 231 | flag_consts: HashMap<(String, String), String>, |
| Add closures and unsafe; base16ct's lower.rs and upper.rs go through 0a375d8 nandithebull 9h ago | 232 | /// `use` brings a name into scope from another module. Flattening loses |
| 233 | /// the module structure, so the mapping is recorded and consulted when a |
| 234 | /// bare call is resolved. |
| 235 | use_map: HashMap<String, String>, |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 236 | /// struct name -> (field, type) |
| 237 | structs: HashMap<String, Vec<(String, Nim)>>, |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 238 | enums: HashMap<String, EnumDef>, |
| 239 | /// variant name -> enums declaring it. A variant named by more than one |
| 240 | /// enum must be written qualified, or it is rejected as ambiguous. |
| 241 | variant_owner: HashMap<String, Vec<String>>, |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 242 | /// `(receiver type, method) -> signature`. Keyed by type because two |
| 243 | /// types may define the same method name, and Nim tells them apart by |
| 244 | /// overload resolution on the first parameter. |
| 245 | methods: HashMap<(String, String), Sig>, |
| 246 | /// The formatting traits implemented for each type, so `{}`/`{:?}`/`{:x}` |
| 247 | /// on a user type can be checked rather than assumed. |
| 248 | fmt_impls: HashMap<(String, String), ()>, |
| 249 | /// `(from, to)` conversions declared by `impl From<A> for B`. |
| 250 | from_impls: HashMap<(String, String), String>, |
| Transpile a second crate, adler2, to test whether any of this generalises 5fdd5be nandithebull 8h ago | 251 | /// Operator traits implemented for a type, so `a += b` on a user type can |
| 252 | /// be dispatched to the impl rather than to Nim's built-in operator. |
| 253 | op_impls: HashMap<(String, String), ()>, |
| 254 | /// `(type, method) -> nim name`, for calls written as `Type::method(..)`. |
| 255 | statics: HashMap<(String, String), String>, |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 256 | /// Forward declarations, emitted between the type definitions and the |
| 257 | /// bodies. Rust has no declaration-before-use rule and Nim does, so every |
| 258 | /// proc is declared up front rather than the input being reordered -- |
| 259 | /// which would not work for mutual recursion anyway. |
| 260 | forwards: Vec<String>, |
| Add closures and unsafe; base16ct's lower.rs and upper.rs go through 0a375d8 nandithebull 9h ago | 261 | /// Element type a `vec![..]` should build, from the binding's annotation. |
| 262 | vec_expect: Option<Nim>, |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 263 | /// While lowering a formatting impl: the `Formatter` parameter's name. |
| 264 | /// Writes through it produce the proc's string result. |
| 265 | fmt_param: Option<String>, |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 266 | /// `type X<T> = ...`, expanded before any type is mapped. |
| 267 | aliases: HashMap<String, (Vec<String>, syn::Type)>, |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 268 | /// Module names supplied as separate input files. A `mod x;` naming one |
| 269 | /// of these is satisfied by that file having been passed in. |
| 270 | pub modules: Vec<String>, |
| Fail when nothing was translated, not just when the file is empty 0777223 nandithebull 8h ago | 271 | /// How many items were actually translated. If this is zero the input |
| 272 | /// produced nothing but the prelude, and reporting success for that is |
| 273 | /// the precise failure this project exists to avoid -- see `findings/`. |
| 274 | emitted: usize, |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 275 | /// Cargo features that are on, as `--cfg feature=<name>`. `#[cfg]` is |
| 276 | /// evaluated against these exactly as rustc would, so an item that is |
| 277 | /// dropped here is genuinely not part of the program being compiled. |
| 278 | pub features: Vec<String>, |
| 279 | dropped_by_cfg: usize, |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 280 | /// Return type of the proc being lowered, so `return e` and a trailing |
| 281 | /// expression can type their literals the way Rust's inference would. |
| 282 | ret: Option<Nim>, |
| 283 | /// `(name, type)` that the arms of the `if`/`match` being lowered as a |
| 284 | /// statement must assign their value to. |
| 285 | target: Option<(String, Option<Nim>)>, |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 286 | /// Set while lowering a `while` condition, which Nim re-evaluates each |
| 287 | /// iteration and so cannot have statements hoisted out of it. |
| 288 | in_loop_cond: bool, |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 289 | tmp: usize, |
| 290 | } |
| 291 | |
| 292 | impl Lowerer { |
| 293 | pub fn new() -> Self { |
| 294 | Lowerer { |
| 295 | out: String::new(), |
| 296 | indent: 0, |
| 297 | scopes: vec![HashMap::new()], |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 298 | alias_scopes: vec![HashMap::new()], |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 299 | fns: HashMap::new(), |
| Add closures and unsafe; base16ct's lower.rs and upper.rs go through 0a375d8 nandithebull 9h ago | 300 | cur_mod: String::new(), |
| Transpile a second crate, adler2, to test whether any of this generalises 5fdd5be nandithebull 8h ago | 301 | self_ty: None, |
| Add generics; transpile the part of cosmic-theme that is reachable ff34e1b nandithebull 7h ago | 302 | impl_generics: Vec::new(), |
| 303 | fn_generics: Vec::new(), |
| 304 | type_generics: HashMap::new(), |
| Add associated types and consts, and test whether the blocker stack bottoms out 8354895 nandithebull 7h ago | 305 | assoc: HashMap::new(), |
| 306 | assoc_consts: HashMap::new(), |
| Lower `extern "C"` blocks to Nim importc; do not transpile libc 7db7991 nandithebull 6h ago | 307 | foreign: std::collections::HashSet::new(), |
| 308 | const_ptrs: std::collections::HashSet::new(), |
| Expand `macro_rules!` rather than translating it to a Nim template 04eb29f nandithebull 6h ago | 309 | mrules: HashMap::new(), |
| 310 | mrules_bad: HashMap::new(), |
| Expand multi-rule and recursive macro_rules d459281 nandithebull 5h ago | 311 | macro_depth: 0, |
| Lower `bitflags!` directly, checked against the real crate af6e50f nandithebull 7h ago | 312 | bitflags: std::collections::HashSet::new(), |
| 313 | flag_consts: HashMap::new(), |
| Add closures and unsafe; base16ct's lower.rs and upper.rs go through 0a375d8 nandithebull 9h ago | 314 | use_map: HashMap::new(), |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 315 | structs: HashMap::new(), |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 316 | enums: HashMap::new(), |
| 317 | variant_owner: HashMap::new(), |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 318 | methods: HashMap::new(), |
| 319 | fmt_impls: HashMap::new(), |
| 320 | from_impls: HashMap::new(), |
| Transpile a second crate, adler2, to test whether any of this generalises 5fdd5be nandithebull 8h ago | 321 | op_impls: HashMap::new(), |
| 322 | statics: HashMap::new(), |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 323 | fmt_param: None, |
| Add closures and unsafe; base16ct's lower.rs and upper.rs go through 0a375d8 nandithebull 9h ago | 324 | vec_expect: None, |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 325 | forwards: Vec::new(), |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 326 | aliases: HashMap::new(), |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 327 | modules: Vec::new(), |
| Fail when nothing was translated, not just when the file is empty 0777223 nandithebull 8h ago | 328 | emitted: 0, |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 329 | features: Vec::new(), |
| 330 | dropped_by_cfg: 0, |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 331 | ret: None, |
| 332 | target: None, |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 333 | in_loop_cond: false, |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 334 | tmp: 0, |
| 335 | } |
| 336 | } |
| 337 | |
| 338 | // ------------------------------------------------------------ emission |
| 339 | |
| 340 | fn line(&mut self, s: &str) { |
| 341 | for _ in 0..self.indent { |
| 342 | self.out.push_str(" "); |
| 343 | } |
| 344 | self.out.push_str(s); |
| 345 | self.out.push('\n'); |
| 346 | } |
| 347 | |
| 348 | fn blank(&mut self) { |
| 349 | self.out.push('\n'); |
| 350 | } |
| 351 | |
| 352 | fn fresh(&mut self, hint: &str) -> String { |
| 353 | self.tmp += 1; |
| 354 | format!("rsTmp{}{}", hint, self.tmp) |
| 355 | } |
| 356 | |
| 357 | // --------------------------------------------------------------- scope |
| 358 | |
| 359 | fn push_scope(&mut self) { |
| 360 | self.scopes.push(HashMap::new()); |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 361 | self.alias_scopes.push(HashMap::new()); |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 362 | } |
| 363 | fn pop_scope(&mut self) { |
| 364 | self.scopes.pop(); |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 365 | self.alias_scopes.pop(); |
| 366 | } |
| 367 | fn bind_alias(&mut self, name: &str, a: Alias) { |
| 368 | self.alias_scopes |
| 369 | .last_mut() |
| 370 | .unwrap() |
| 371 | .insert(name.to_string(), a); |
| 372 | } |
| 373 | fn lookup_alias(&self, name: &str) -> Option<Alias> { |
| 374 | self.alias_scopes |
| 375 | .iter() |
| 376 | .rev() |
| 377 | .find_map(|s| s.get(name).cloned()) |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 378 | } |
| 379 | fn bind(&mut self, name: &str, t: Nim) { |
| 380 | self.scopes.last_mut().unwrap().insert(name.to_string(), t); |
| 381 | } |
| 382 | fn lookup(&self, name: &str) -> Option<Nim> { |
| 383 | self.scopes.iter().rev().find_map(|s| s.get(name).cloned()) |
| 384 | } |
| 385 | |
| 386 | // ---------------------------------------------------------------- file |
| 387 | |
| Add closures and unsafe; base16ct's lower.rs and upper.rs go through 0a375d8 nandithebull 9h ago | 388 | pub fn lower_file(&mut self, files: &[(String, syn::File)]) -> Result<String, String> { |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 389 | self.out.push_str(include_str!("prelude.nim")); |
| 390 | self.blank(); |
| 391 | |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 392 | // Pass 0: type aliases. A signature in one file may use an alias |
| 393 | // declared in another, and inputs are given in whatever order suits |
| 394 | // the caller, so aliases are registered before anything is mapped. |
| Add closures and unsafe; base16ct's lower.rs and upper.rs go through 0a375d8 nandithebull 9h ago | 395 | for (m, f) in files { |
| 396 | self.cur_mod = m.clone(); |
| 397 | for item in &f.items { |
| 398 | self.collect_aliases(item)?; |
| 399 | } |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 400 | } |
| 401 | |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 402 | // Pass 1: signatures and struct shapes, so that a call can be typed |
| 403 | // regardless of declaration order (Rust has no forward declarations). |
| Add closures and unsafe; base16ct's lower.rs and upper.rs go through 0a375d8 nandithebull 9h ago | 404 | for (m, f) in files { |
| 405 | self.cur_mod = m.clone(); |
| 406 | for item in &f.items { |
| 407 | self.collect(item)?; |
| 408 | } |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 409 | } |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 410 | // Pass 2: type definitions, which every signature may mention. |
| Add closures and unsafe; base16ct's lower.rs and upper.rs go through 0a375d8 nandithebull 9h ago | 411 | for (m, f) in files { |
| 412 | self.cur_mod = m.clone(); |
| 413 | for item in &f.items { |
| 414 | self.item_types(item)?; |
| 415 | } |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 416 | } |
| 417 | |
| 418 | // Pass 3: forward declarations. Rust imposes no declaration order and |
| 419 | // Nim does, so everything is declared before any body is emitted; |
| 420 | // reordering the input would not handle mutual recursion anyway. |
| 421 | if !self.forwards.is_empty() { |
| 422 | for f in self.forwards.clone() { |
| 423 | self.line(&f); |
| 424 | } |
| 425 | self.blank(); |
| 426 | } |
| 427 | |
| 428 | // Pass 4: bodies. |
| Add closures and unsafe; base16ct's lower.rs and upper.rs go through 0a375d8 nandithebull 9h ago | 429 | for (m, f) in files { |
| 430 | self.cur_mod = m.clone(); |
| 431 | for item in &f.items { |
| 432 | self.item(item)?; |
| 433 | } |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 434 | } |
| 435 | |
| Fail when nothing was translated, not just when the file is empty 0777223 nandithebull 8h ago | 436 | // An input that translates to nothing is a failure, however plausible |
| 437 | // the output file looks. The prelude alone is not a translation. |
| 438 | if self.emitted == 0 { |
| 439 | return Err(format!( |
| 440 | "nothing was translated: the input has no items this lowering \ |
| 441 | emits{}. Writing a file containing only the prelude would \ |
| 442 | report success for work that was not done", |
| 443 | if self.dropped_by_cfg > 0 { |
| 444 | format!( |
| 445 | " ({} item(s) were dropped by `#[cfg]`; enable them with \ |
| 446 | `--cfg feature=<name>`)", |
| 447 | self.dropped_by_cfg |
| 448 | ) |
| 449 | } else { |
| 450 | String::new() |
| 451 | } |
| 452 | )); |
| 453 | } |
| 454 | |
| Add closures and unsafe; base16ct's lower.rs and upper.rs go through 0a375d8 nandithebull 9h ago | 455 | if self.fns.contains_key(&(String::new(), "main".to_string())) { |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 456 | self.blank(); |
| 457 | self.line("when isMainModule:"); |
| 458 | self.indent += 1; |
| 459 | self.line("try:"); |
| 460 | self.line(" main()"); |
| 461 | // Rust's panic exits 101 with a message on stderr. Nim's Defects |
| 462 | // exit 1. Mapping them here is what keeps the differential runner's |
| 463 | // exit-status comparison meaningful for panicking programs. |
| 464 | self.line("except RustPanic as e:"); |
| 465 | self.line(" stderr.writeLine(\"thread 'main' panicked: \" & e.msg)"); |
| 466 | self.line(" quit(101)"); |
| 467 | self.line("except Defect as e:"); |
| 468 | self.line(" stderr.writeLine(\"thread 'main' panicked: \" & e.msg)"); |
| 469 | self.line(" quit(101)"); |
| 470 | self.indent -= 1; |
| 471 | } |
| 472 | Ok(std::mem::take(&mut self.out)) |
| 473 | } |
| 474 | |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 475 | fn collect_aliases(&mut self, item: &Item) -> Result<(), String> { |
| 476 | if !self.cfg_keeps(item_attrs(item))? { |
| 477 | return Ok(()); |
| 478 | } |
| 479 | match item { |
| Add closures and unsafe; base16ct's lower.rs and upper.rs go through 0a375d8 nandithebull 9h ago | 480 | Item::Use(u) => self.collect_use(&u.tree, &[]), |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 481 | Item::Type(t) => { |
| 482 | let params: Vec<String> = t |
| 483 | .generics |
| 484 | .params |
| 485 | .iter() |
| 486 | .filter_map(|g| match g { |
| 487 | syn::GenericParam::Type(t) => Some(t.ident.to_string()), |
| 488 | _ => None, |
| 489 | }) |
| 490 | .collect(); |
| 491 | self.aliases |
| 492 | .insert(t.ident.to_string(), (params, (*t.ty).clone())); |
| 493 | } |
| 494 | Item::Mod(m) if m.content.is_some() => { |
| 495 | let items = m.content.as_ref().map(|(_, i)| i.clone()).unwrap_or_default(); |
| 496 | for i in &items { |
| 497 | self.collect_aliases(i)?; |
| 498 | } |
| 499 | } |
| 500 | _ => {} |
| 501 | } |
| 502 | Ok(()) |
| 503 | } |
| 504 | |
| Add closures and unsafe; base16ct's lower.rs and upper.rs go through 0a375d8 nandithebull 9h ago | 505 | /// Record what a `use` brings into scope, as `name -> module`. |
| 506 | fn collect_use(&mut self, t: &syn::UseTree, prefix: &[String]) { |
| 507 | use syn::UseTree; |
| 508 | match t { |
| 509 | UseTree::Path(p) => { |
| 510 | let mut pre = prefix.to_vec(); |
| 511 | pre.push(p.ident.to_string()); |
| 512 | self.collect_use(&p.tree, &pre); |
| 513 | } |
| 514 | UseTree::Group(g) => { |
| 515 | for t in &g.items { |
| 516 | self.collect_use(t, prefix); |
| 517 | } |
| 518 | } |
| 519 | UseTree::Name(n) => { |
| 520 | let m = module_of(prefix); |
| 521 | self.use_map.insert(n.ident.to_string(), m); |
| 522 | } |
| 523 | UseTree::Rename(r) => { |
| 524 | let m = module_of(prefix); |
| 525 | self.use_map.insert(r.rename.to_string(), m); |
| 526 | } |
| 527 | // A glob brings in an unknown set of names; resolution falls back |
| 528 | // to the current module and the root, as it would without it. |
| 529 | UseTree::Glob(_) => {} |
| 530 | } |
| 531 | } |
| 532 | |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 533 | fn collect(&mut self, item: &Item) -> Result<(), String> { |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 534 | // A `#[cfg(..)]` item exists only under some feature set. Dropping it |
| 535 | // silently would change what the program does; picking a feature set |
| 536 | // on the user's behalf would be a guess. So it is reported, except on |
| 537 | // items that carry no runtime meaning here anyway. |
| 538 | if !self.cfg_keeps(item_attrs(item))? { |
| 539 | self.dropped_by_cfg += 1; |
| 540 | return Ok(()); |
| 541 | } |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 542 | match item { |
| 543 | Item::Fn(f) => { |
| 544 | let (params, ret) = self.signature(&f.sig)?; |
| Add generics; transpile the part of cosmic-theme that is reachable ff34e1b nandithebull 7h ago | 545 | let gen_names = Self::generics_of(&f.sig.generics); |
| Add closures and unsafe; base16ct's lower.rs and upper.rs go through 0a375d8 nandithebull 9h ago | 546 | let name = f.sig.ident.to_string(); |
| 547 | let nim = self.fn_name(&self.cur_mod, &name); |
| 548 | self.forwards.push(self.head_of(&nim, &f.sig, None)?); |
| 549 | self.fns |
| Add generics; transpile the part of cosmic-theme that is reachable ff34e1b nandithebull 7h ago | 550 | .insert((self.cur_mod.clone(), name), Sig { params, ret, generics: gen_names.clone() }); |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 551 | } |
| 552 | Item::Struct(s) => { |
| Add generics; transpile the part of cosmic-theme that is reachable ff34e1b nandithebull 7h ago | 553 | if s.generics.params.iter().any(|p| matches!(p, syn::GenericParam::Const(_))) { |
| 554 | return Err(format!( |
| 555 | "`struct {}` has a const generic parameter, which Nim has \ |
| 556 | no equivalent for", |
| 557 | s.ident |
| 558 | )); |
| 559 | } |
| 560 | let g = Self::generics_of(&s.generics); |
| 561 | // The parameters must be in scope while the field types are |
| 562 | // mapped, so that `T` resolves to itself rather than to an |
| 563 | // unknown named type. |
| 564 | self.type_generics.insert(s.ident.to_string(), g); |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 565 | let mut fields = Vec::new(); |
| 566 | for (i, f) in s.fields.iter().enumerate() { |
| 567 | let name = match &f.ident { |
| 568 | Some(id) => id.to_string(), |
| 569 | None => format!("f{i}"), // tuple struct |
| 570 | }; |
| Add display.rs and the alloc half: all of base16ct now goes through afb2a6e nandithebull 9h ago | 571 | // A field of `&[T]` / `&str` type is a borrow, and Nim's |
| 572 | // view types allow it as an object field, so it stays a |
| 573 | // view rather than being copied into a `seq`. |
| 574 | let t = self.map_ty(&f.ty)?; |
| 575 | let t = if returns_borrow(&f.ty) { t.unvar() } else { t.owned() }; |
| 576 | fields.push((name, t)); |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 577 | } |
| 578 | self.structs.insert(s.ident.to_string(), fields); |
| 579 | } |
| Lower `bitflags!` directly, checked against the real crate af6e50f nandithebull 7h ago | 580 | Item::Macro(m) if path_name(&m.mac.path) == "bitflags" => { |
| 581 | self.collect_bitflags(&m.mac)?; |
| 582 | } |
| Expand `macro_rules!` rather than translating it to a Nim template 04eb29f nandithebull 6h ago | 583 | // A `macro_rules!` definition is recorded, not emitted: it is |
| 584 | // expanded at each call site, where the types its body needs are |
| 585 | // known. See `src/mrules.rs` for why that beats translating it |
| 586 | // into a Nim template. |
| 587 | Item::Macro(m) if path_name(&m.mac.path) == "macro_rules" => { |
| 588 | if let Some(name) = &m.ident { |
| 589 | match crate::mrules::parse(m.mac.tokens.clone()) { |
| 590 | Ok(def) => { |
| 591 | self.mrules.insert(name.to_string(), def); |
| 592 | } |
| 593 | Err(why) => { |
| 594 | // Recorded as unusable rather than silently absent: |
| 595 | // a call site gets this reason instead of "unknown |
| 596 | // macro". |
| 597 | self.mrules_bad.insert(name.to_string(), why); |
| 598 | } |
| 599 | } |
| 600 | } |
| 601 | } |
| Lower `extern "C"` blocks to Nim importc; do not transpile libc 7db7991 nandithebull 6h ago | 602 | Item::ForeignMod(f) => { |
| 603 | for it in &f.items { |
| 604 | if let syn::ForeignItem::Fn(fi) = it { |
| 605 | let (params, ret) = self.signature(&fi.sig)?; |
| 606 | self.fns.insert( |
| 607 | (self.cur_mod.clone(), fi.sig.ident.to_string()), |
| 608 | Sig { params, ret, generics: Vec::new() }, |
| 609 | ); |
| 610 | } |
| 611 | } |
| 612 | } |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 613 | Item::Mod(m) if m.content.is_some() => { |
| 614 | let items = m.content.as_ref().map(|(_, i)| i.clone()).unwrap_or_default(); |
| 615 | for i in &items { |
| 616 | self.collect(i)?; |
| 617 | } |
| 618 | } |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 619 | Item::Type(t) => { |
| 620 | let params: Vec<String> = t |
| 621 | .generics |
| 622 | .params |
| 623 | .iter() |
| 624 | .filter_map(|g| match g { |
| 625 | syn::GenericParam::Type(t) => Some(t.ident.to_string()), |
| 626 | _ => None, |
| 627 | }) |
| 628 | .collect(); |
| 629 | self.aliases |
| 630 | .insert(t.ident.to_string(), (params, (*t.ty).clone())); |
| 631 | } |
| 632 | Item::Enum(e) => { |
| 633 | let name = e.ident.to_string(); |
| Add generics; transpile the part of cosmic-theme that is reachable ff34e1b nandithebull 7h ago | 634 | if e.generics.params.iter().any(|p| matches!(p, syn::GenericParam::Const(_))) { |
| 635 | return Err(format!( |
| 636 | "`enum {name}` has a const generic parameter, which Nim \ |
| 637 | has no equivalent for" |
| 638 | )); |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 639 | } |
| Add generics; transpile the part of cosmic-theme that is reachable ff34e1b nandithebull 7h ago | 640 | self.type_generics |
| 641 | .insert(name.clone(), Self::generics_of(&e.generics)); |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 642 | let mut variants = Vec::new(); |
| 643 | for v in &e.variants { |
| 644 | let vname = v.ident.to_string(); |
| Lower the `log` facade, and add explicit enum discriminants 12c0a01 nandithebull 6h ago | 645 | let discriminant = match &v.discriminant { |
| 646 | Some((_, e)) => Some(self.expr(e)?.code), |
| 647 | None => None, |
| 648 | }; |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 649 | let mut fields = Vec::new(); |
| 650 | for (i, f) in v.fields.iter().enumerate() { |
| 651 | // Nim requires the branches of a variant object to have |
| 652 | // distinct field names, so each is prefixed. |
| 653 | let fname = match &f.ident { |
| 654 | Some(id) => format!("{vname}_{id}"), |
| 655 | None => format!("{vname}_f{i}"), |
| 656 | }; |
| Add display.rs and the alloc half: all of base16ct now goes through afb2a6e nandithebull 9h ago | 657 | let t = self.map_ty(&f.ty)?; |
| 658 | let t = if returns_borrow(&f.ty) { t.unvar() } else { t.owned() }; |
| 659 | fields.push((fname, t)); |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 660 | } |
| Lower the `log` facade, and add explicit enum discriminants 12c0a01 nandithebull 6h ago | 661 | variants.push(Variant { name: vname, discriminant, fields }); |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 662 | } |
| 663 | let simple = variants.iter().all(|v| v.fields.is_empty()); |
| 664 | for v in &variants { |
| 665 | self.variant_owner |
| 666 | .entry(v.name.clone()) |
| 667 | .or_default() |
| 668 | .push(name.clone()); |
| 669 | } |
| 670 | self.enums.insert( |
| 671 | name.clone(), |
| 672 | EnumDef { name, simple, variants }, |
| 673 | ); |
| 674 | } |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 675 | Item::Impl(im) => { |
| Add generics; transpile the part of cosmic-theme that is reachable ff34e1b nandithebull 7h ago | 676 | let outer_g = |
| 677 | std::mem::replace(&mut self.impl_generics, Self::generics_of(&im.generics)); |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 678 | let self_ty = self.map_ty(&im.self_ty)?; |
| Transpile a second crate, adler2, to test whether any of this generalises 5fdd5be nandithebull 8h ago | 679 | let outer_self = self.self_ty.replace(self_ty.clone()); |
| 680 | let r = self.collect_impl(im, &self_ty); |
| 681 | self.self_ty = outer_self; |
| Add generics; transpile the part of cosmic-theme that is reachable ff34e1b nandithebull 7h ago | 682 | self.impl_generics = outer_g; |
| Transpile a second crate, adler2, to test whether any of this generalises 5fdd5be nandithebull 8h ago | 683 | return r; |
| 684 | } |
| 685 | _ => {} |
| 686 | } |
| 687 | Ok(()) |
| 688 | } |
| 689 | |
| 690 | fn collect_impl(&mut self, im: &syn::ItemImpl, self_ty: &Nim) -> Result<(), String> { |
| 691 | { |
| 692 | let self_ty = self_ty.clone(); |
| 693 | let tyname = type_name(&self_ty); |
| Add associated types and consts, and test whether the blocker stack bottoms out 8354895 nandithebull 7h ago | 694 | // Associated types first: a signature in the same block may name |
| 695 | // one, and it has to resolve by the time that signature is mapped. |
| 696 | for it in &im.items { |
| 697 | if let syn::ImplItem::Type(t) = it { |
| 698 | let v = self.map_ty(&t.ty)?; |
| 699 | self.assoc.insert((tyname.clone(), t.ident.to_string()), v); |
| 700 | } |
| 701 | } |
| Transpile a second crate, adler2, to test whether any of this generalises 5fdd5be nandithebull 8h ago | 702 | if let Some((path, _)) = &im.trait_ { |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 703 | let tr = path_name(path); |
| 704 | if im.items.is_empty() { |
| 705 | // A marker trait with no items. We do not model trait |
| 706 | // resolution at all, so it generates nothing; any use |
| 707 | // that actually needed the trait (a `dyn`, a bound) is |
| 708 | // rejected where it appears. |
| 709 | return Ok(()); |
| 710 | } |
| 711 | if is_fmt_trait(&tr) { |
| 712 | self.forwards.push(format!( |
| 713 | "proc {}*(self: {}): string", |
| 714 | fmt_proc(&tr), |
| 715 | self_ty.render() |
| 716 | )); |
| 717 | self.fmt_impls.insert((tyname, tr), ()); |
| 718 | return Ok(()); |
| 719 | } |
| 720 | if tr == "From" { |
| 721 | let syn::ImplItem::Fn(m) = &im.items[0] else { |
| 722 | return Err("`impl From` must contain `fn from`".into()); |
| 723 | }; |
| 724 | let (params, _) = self.signature(&m.sig)?; |
| 725 | let src = params |
| 726 | .first() |
| 727 | .ok_or("`fn from` takes one argument")? |
| 728 | .clone(); |
| 729 | let name = format!("rsFrom{}{}", tyname, type_name(&src)); |
| 730 | self.forwards.push(self.head_of(&name, &m.sig, None)?); |
| 731 | self.from_impls |
| 732 | .insert((type_name(&src), tyname), name); |
| 733 | return Ok(()); |
| 734 | } |
| Transpile a second crate, adler2, to test whether any of this generalises 5fdd5be nandithebull 8h ago | 735 | // Any other trait: its methods are emitted as procs on |
| 736 | // the type, named after the trait so two traits declaring |
| 737 | // the same method name do not collide. The *trait* is not |
| 738 | // modelled -- no dynamic dispatch, no bounds -- and a use |
| 739 | // that needs it is rejected where it appears. |
| 740 | if let Some(op) = operator_trait(&tr) { |
| 741 | self.op_impls.insert((tyname.clone(), op.to_string()), ()); |
| 742 | } |
| 743 | for it in &im.items { |
| Add associated types and consts, and test whether the blocker stack bottoms out 8354895 nandithebull 7h ago | 744 | // Already recorded above; a const is emitted with the |
| 745 | // bodies. |
| 746 | if matches!(it, syn::ImplItem::Type(_) | syn::ImplItem::Const(_)) { |
| 747 | continue; |
| 748 | } |
| Transpile a second crate, adler2, to test whether any of this generalises 5fdd5be nandithebull 8h ago | 749 | let syn::ImplItem::Fn(m) = it else { |
| Add associated types and consts, and test whether the blocker stack bottoms out 8354895 nandithebull 7h ago | 750 | return Err(format!( |
| 751 | "unsupported item in `impl {tr}`: only `fn`, \ |
| 752 | `type` and `const` are implemented" |
| 753 | )); |
| Transpile a second crate, adler2, to test whether any of this generalises 5fdd5be nandithebull 8h ago | 754 | }; |
| 755 | let mname = m.sig.ident.to_string(); |
| 756 | let (mut params, ret) = self.signature(&m.sig)?; |
| Add generics; transpile the part of cosmic-theme that is reachable ff34e1b nandithebull 7h ago | 757 | let mut gen_names = self.impl_generics.clone(); |
| 758 | gen_names.extend(Self::generics_of(&m.sig.generics)); |
| Transpile a second crate, adler2, to test whether any of this generalises 5fdd5be nandithebull 8h ago | 759 | let recv = if takes_self(&m.sig) { |
| 760 | params.insert(0, self_ty.clone()); |
| 761 | Some(self_ty.clone()) |
| 762 | } else { |
| 763 | None |
| 764 | }; |
| 765 | let nim = trait_method_name(&tyname, &tr, &mname); |
| 766 | self.forwards.push(self.head_of(&nim, &m.sig, recv.as_ref())?); |
| 767 | self.methods |
| Add generics; transpile the part of cosmic-theme that is reachable ff34e1b nandithebull 7h ago | 768 | .insert((tyname.clone(), mname.clone()), Sig { params, ret, generics: gen_names.clone() }); |
| Transpile a second crate, adler2, to test whether any of this generalises 5fdd5be nandithebull 8h ago | 769 | self.statics.insert((tyname.clone(), mname), nim); |
| 770 | } |
| 771 | return Ok(()); |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 772 | } |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 773 | for it in &im.items { |
| 774 | if let syn::ImplItem::Fn(m) = it { |
| 775 | let (mut params, ret) = self.signature(&m.sig)?; |
| Add generics; transpile the part of cosmic-theme that is reachable ff34e1b nandithebull 7h ago | 776 | let mut gen_names = self.impl_generics.clone(); |
| 777 | gen_names.extend(Self::generics_of(&m.sig.generics)); |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 778 | if takes_self(&m.sig) { |
| 779 | params.insert(0, self_ty.clone()); |
| 780 | } |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 781 | let recv = if takes_self(&m.sig) { Some(self_ty.clone()) } else { None }; |
| Transpile a second crate, adler2, to test whether any of this generalises 5fdd5be nandithebull 8h ago | 782 | let nim = self.fn_name(&self.cur_mod, &m.sig.ident.to_string()); |
| 783 | let head = self.head_of(&nim, &m.sig, recv.as_ref())?; |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 784 | self.forwards.push(head); |
| 785 | self.methods |
| Add generics; transpile the part of cosmic-theme that is reachable ff34e1b nandithebull 7h ago | 786 | .insert((tyname.clone(), m.sig.ident.to_string()), Sig { params, ret, generics: gen_names.clone() }); |
| Transpile a second crate, adler2, to test whether any of this generalises 5fdd5be nandithebull 8h ago | 787 | self.statics |
| 788 | .insert((tyname.clone(), m.sig.ident.to_string()), nim); |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 789 | } |
| 790 | } |
| 791 | } |
| 792 | Ok(()) |
| 793 | } |
| 794 | |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 795 | /// Whether `#[cfg(..)]` keeps this item, given the enabled features. |
| 796 | /// |
| 797 | /// This is evaluation, not approximation: rustc does the same thing, and |
| 798 | /// an item whose predicate is false is not part of the compiled program. |
| 799 | /// A predicate that cannot be evaluated is reported rather than assumed. |
| 800 | fn cfg_keeps(&self, attrs: &[syn::Attribute]) -> Result<bool, String> { |
| 801 | for a in attrs { |
| 802 | if a.path().is_ident("cfg") { |
| 803 | let pred: syn::Meta = a |
| 804 | .parse_args() |
| 805 | .map_err(|e| format!("cannot parse `#[cfg(..)]`: {e}"))?; |
| 806 | if !self.cfg_eval(&pred)? { |
| 807 | return Ok(false); |
| 808 | } |
| 809 | } |
| 810 | } |
| 811 | Ok(true) |
| 812 | } |
| 813 | |
| 814 | fn cfg_eval(&self, m: &syn::Meta) -> Result<bool, String> { |
| 815 | match m { |
| Transpile a second crate, adler2, to test whether any of this generalises 5fdd5be nandithebull 8h ago | 816 | // Bare flags whose value is determined by the profile this project |
| 817 | // models: a normal (non-`--test`) debug build, not a docs build. |
| 818 | // Anything platform-specific stays rejected, since we would be |
| 819 | // picking a target on the user's behalf. |
| 820 | syn::Meta::Path(p) if p.is_ident("test") => Ok(false), |
| 821 | syn::Meta::Path(p) if p.is_ident("debug_assertions") => Ok(true), |
| 822 | syn::Meta::Path(p) if p.is_ident("docsrs") || p.is_ident("doc") => Ok(false), |
| Evaluate host cfg predicates, and measure what that actually buys 0e6c394 nandithebull 8h ago | 823 | syn::Meta::Path(p) if p.is_ident("doctest") || p.is_ident("miri") => Ok(false), |
| 824 | // Host facts. The generated Nim is compiled for this machine, so |
| 825 | // these are known rather than chosen. See DESIGN.md item 10: it |
| 826 | // does make the output host-shaped. |
| 827 | syn::Meta::Path(p) if p.is_ident("unix") => Ok(cfg!(unix)), |
| 828 | syn::Meta::Path(p) if p.is_ident("windows") => Ok(cfg!(windows)), |
| 829 | syn::Meta::NameValue(nv) |
| 830 | if nv.path.is_ident("target_os") |
| 831 | || nv.path.is_ident("target_arch") |
| 832 | || nv.path.is_ident("target_family") |
| 833 | || nv.path.is_ident("target_vendor") => |
| 834 | { |
| 835 | let syn::Expr::Lit(syn::ExprLit { lit: Lit::Str(s), .. }) = &nv.value else { |
| 836 | return Err("this `cfg` key expects a string".into()); |
| 837 | }; |
| 838 | let key = nv.path.get_ident().map(|i| i.to_string()).unwrap_or_default(); |
| 839 | Ok(s.value() |
| 840 | == match key.as_str() { |
| 841 | "target_os" => std::env::consts::OS, |
| 842 | "target_arch" => std::env::consts::ARCH, |
| 843 | "target_family" => std::env::consts::FAMILY, |
| 844 | _ => "unknown", |
| 845 | }) |
| 846 | } |
| Transpile a second crate, adler2, to test whether any of this generalises 5fdd5be nandithebull 8h ago | 847 | // The generated Nim is compiled for the same machine, so the |
| 848 | // target's word size and endianness are known rather than |
| 849 | // guessed. This does mean the output is host-shaped: a crate that |
| 850 | // branches on pointer width has had that branch decided here. |
| 851 | syn::Meta::NameValue(nv) if nv.path.is_ident("target_pointer_width") => { |
| 852 | let syn::Expr::Lit(syn::ExprLit { lit: Lit::Str(s), .. }) = &nv.value else { |
| 853 | return Err("`target_pointer_width = ..` expects a string".into()); |
| 854 | }; |
| 855 | Ok(s.value() == (usize::BITS).to_string()) |
| 856 | } |
| Lower the `log` facade, and add explicit enum discriminants 12c0a01 nandithebull 6h ago | 857 | // Every integer width and pointer-sized atomic exists on the |
| 858 | // targets Nim builds for here; like the other host facts this is |
| 859 | // read off the machine rather than chosen. |
| 860 | syn::Meta::NameValue(nv) if nv.path.is_ident("target_has_atomic") => { |
| 861 | let syn::Expr::Lit(syn::ExprLit { lit: Lit::Str(s), .. }) = &nv.value else { |
| 862 | return Err("`target_has_atomic = ..` expects a string".into()); |
| 863 | }; |
| 864 | Ok(matches!( |
| 865 | s.value().as_str(), |
| 866 | "8" | "16" | "32" | "64" | "ptr" |
| 867 | )) |
| 868 | } |
| Transpile a second crate, adler2, to test whether any of this generalises 5fdd5be nandithebull 8h ago | 869 | syn::Meta::NameValue(nv) if nv.path.is_ident("target_endian") => { |
| 870 | let syn::Expr::Lit(syn::ExprLit { lit: Lit::Str(s), .. }) = &nv.value else { |
| 871 | return Err("`target_endian = ..` expects a string".into()); |
| 872 | }; |
| 873 | Ok(s.value() == if cfg!(target_endian = "big") { "big" } else { "little" }) |
| 874 | } |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 875 | syn::Meta::NameValue(nv) if nv.path.is_ident("feature") => { |
| 876 | let syn::Expr::Lit(syn::ExprLit { lit: Lit::Str(s), .. }) = &nv.value else { |
| 877 | return Err("`feature = ..` expects a string".into()); |
| 878 | }; |
| 879 | Ok(self.features.iter().any(|f| *f == s.value())) |
| 880 | } |
| 881 | syn::Meta::List(l) if l.path.is_ident("not") => { |
| 882 | let inner: syn::Meta = l.parse_args().map_err(|e| e.to_string())?; |
| 883 | Ok(!self.cfg_eval(&inner)?) |
| 884 | } |
| 885 | syn::Meta::List(l) if l.path.is_ident("all") || l.path.is_ident("any") => { |
| 886 | let items: syn::punctuated::Punctuated<syn::Meta, syn::Token![,]> = l |
| 887 | .parse_args_with(syn::punctuated::Punctuated::parse_terminated) |
| 888 | .map_err(|e| e.to_string())?; |
| 889 | let all = l.path.is_ident("all"); |
| 890 | let mut acc = all; |
| 891 | for i in &items { |
| 892 | let v = self.cfg_eval(i)?; |
| 893 | acc = if all { acc && v } else { acc || v }; |
| 894 | } |
| 895 | Ok(acc) |
| 896 | } |
| 897 | other => Err(format!( |
| Evaluate host cfg predicates, and measure what that actually buys 0e6c394 nandithebull 8h ago | 898 | "`#[cfg({})]` is not a predicate rustnim can evaluate. \ |
| 899 | Features (`--cfg feature=..`), host facts (`unix`, `windows`, \ |
| 900 | `target_os`, `target_arch`, `target_family`, \ |
| 901 | `target_pointer_width`, `target_endian`), `doc`/`doctest`/\ |
| 902 | `miri`, and `not`/`all`/`any` over those are. A custom or \ |
| 903 | build-script `cfg` has no value we could know", |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 904 | quote_meta(other) |
| 905 | )), |
| 906 | } |
| 907 | } |
| 908 | |
| Transpile a second crate, adler2, to test whether any of this generalises 5fdd5be nandithebull 8h ago | 909 | /// Map a Rust type, resolving `Self` and expanding any `type` alias. Every type in the |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 910 | /// lowering goes through here rather than calling `ty::map` directly, so |
| 911 | /// an alias cannot be missed in one position and honoured in another. |
| 912 | fn map_ty(&self, t: &syn::Type) -> Result<Nim, String> { |
| Add associated types and consts, and test whether the blocker stack bottoms out 8354895 nandithebull 7h ago | 913 | // `Self::Item` names an associated type of the enclosing `impl`. |
| 914 | if let syn::Type::Path(p) = t { |
| 915 | let segs: Vec<String> = |
| 916 | p.path.segments.iter().map(|s| s.ident.to_string()).collect(); |
| 917 | if segs.len() == 2 { |
| 918 | let owner = if segs[0] == "Self" { |
| 919 | self.self_ty.as_ref().map(type_name) |
| 920 | } else { |
| 921 | Some(segs[0].clone()) |
| 922 | }; |
| 923 | if let Some(o) = owner { |
| 924 | if let Some(a) = self.assoc.get(&(o, segs[1].clone())) { |
| 925 | return Ok(a.clone()); |
| 926 | } |
| 927 | } |
| 928 | } |
| 929 | } |
| Transpile a second crate, adler2, to test whether any of this generalises 5fdd5be nandithebull 8h ago | 930 | let n = ty::map(&self.expand(t, 0)?)?; |
| 931 | Ok(self.subst_self(n)) |
| 932 | } |
| 933 | |
| Add generics; transpile the part of cosmic-theme that is reachable ff34e1b nandithebull 7h ago | 934 | /// Substitute a generic type's parameters with the arguments the use site |
| 935 | /// supplies: a field of `Holder<T>` read through a `Holder<i32>` is `i32`. |
| 936 | fn subst_type_args(&self, name: &str, used_as: &Nim, field: Nim) -> Nim { |
| 937 | let Some(params) = self.type_generics.get(name) else { return field }; |
| 938 | if params.is_empty() { |
| 939 | return field; |
| 940 | } |
| 941 | let Nim::Named(n, args) = used_as else { return field }; |
| 942 | if n != name || args.len() != params.len() { |
| 943 | return field; |
| 944 | } |
| 945 | let map: HashMap<String, Nim> = |
| 946 | params.iter().cloned().zip(args.iter().cloned()).collect(); |
| 947 | Self::subst(&field, &map) |
| 948 | } |
| 949 | |
| Transpile a second crate, adler2, to test whether any of this generalises 5fdd5be nandithebull 8h ago | 950 | /// `Self` inside an `impl` block names the type being implemented. |
| 951 | fn subst_self(&self, t: Nim) -> Nim { |
| 952 | let Some(me) = &self.self_ty else { return t }; |
| 953 | match t { |
| 954 | Nim::Named(n, _) if n == "Self" => me.clone(), |
| 955 | Nim::Seq(e) => Nim::Seq(Box::new(self.subst_self(*e))), |
| 956 | Nim::OpenArray(e) => Nim::OpenArray(Box::new(self.subst_self(*e))), |
| 957 | Nim::Array(n, e) => Nim::Array(n, Box::new(self.subst_self(*e))), |
| 958 | Nim::Var(e) => Nim::Var(Box::new(self.subst_self(*e))), |
| 959 | Nim::Named(n, a) => { |
| 960 | Nim::Named(n, a.into_iter().map(|x| self.subst_self(x)).collect()) |
| 961 | } |
| 962 | other => other, |
| 963 | } |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 964 | } |
| 965 | |
| 966 | fn expand(&self, t: &syn::Type, depth: usize) -> Result<syn::Type, String> { |
| 967 | if depth > 16 { |
| 968 | return Err("type alias expansion did not terminate; is it cyclic?".into()); |
| 969 | } |
| 970 | let syn::Type::Path(p) = t else { return Ok(t.clone()) }; |
| 971 | // Only an unqualified name can be one of this file's aliases. |
| 972 | // `fmt::Result` and `core::result::Result` are different types that |
| 973 | // merely end in the same segment. |
| 974 | if p.path.segments.len() != 1 { |
| 975 | return Ok(t.clone()); |
| 976 | } |
| 977 | let Some(seg) = p.path.segments.last() else { return Ok(t.clone()) }; |
| 978 | let Some((params, target)) = self.aliases.get(&seg.ident.to_string()) else { |
| 979 | return Ok(t.clone()); |
| 980 | }; |
| 981 | let args: Vec<syn::Type> = match &seg.arguments { |
| 982 | syn::PathArguments::AngleBracketed(a) => a |
| 983 | .args |
| 984 | .iter() |
| 985 | .filter_map(|g| match g { |
| 986 | GenericArgument::Type(t) => Some(t.clone()), |
| 987 | _ => None, |
| 988 | }) |
| 989 | .collect(), |
| 990 | _ => vec![], |
| 991 | }; |
| 992 | if args.len() != params.len() { |
| 993 | // Flattening several files into one module can bring a crate's own |
| 994 | // alias (`type Result<T> = Result<T, Error>`) into scope at a site |
| 995 | // that meant the builtin (`Result<T, E>`). Rust kept them apart by |
| 996 | // module; here they are told apart by arity, and a use that fits |
| 997 | // neither is left for `ty::map` to report. |
| 998 | return Ok(t.clone()); |
| 999 | } |
| 1000 | self.expand(&substitute(target, params, &args), depth + 1) |
| 1001 | } |
| 1002 | |
| Add generics; transpile the part of cosmic-theme that is reachable ff34e1b nandithebull 7h ago | 1003 | /// The type parameters a generic item declares. |
| 1004 | /// |
| 1005 | /// Trait bounds and `where` clauses are dropped. Nim instantiates a |
| 1006 | /// generic structurally: an operation the bound would have permitted |
| 1007 | /// either exists for the instantiated type or is a compile error at the |
| 1008 | /// instantiation site. So dropping a bound cannot make an accepted |
| 1009 | /// program mean something different — it only makes rustnim accept some |
| 1010 | /// programs rustc would have rejected, which does not matter when the |
| 1011 | /// input is known-good Rust. |
| 1012 | fn generics_of(g: &syn::Generics) -> Vec<String> { |
| 1013 | g.params |
| 1014 | .iter() |
| 1015 | .filter_map(|p| match p { |
| 1016 | syn::GenericParam::Type(t) => Some(t.ident.to_string()), |
| 1017 | _ => None, |
| 1018 | }) |
| 1019 | .collect() |
| 1020 | } |
| 1021 | |
| 1022 | /// Bind a signature's type parameters by matching its declared parameter |
| 1023 | /// types against the actual argument types, then substitute into `ret`. |
| 1024 | /// |
| 1025 | /// This is the small amount of inference a call site needs: Nim will |
| 1026 | /// resolve the instantiation itself, but the *binding* still has to be |
| 1027 | /// annotated with a concrete type, and `T` is not one. |
| 1028 | fn instantiate(sig: &Sig, args: &[Option<Nim>]) -> Nim { |
| 1029 | if sig.generics.is_empty() { |
| 1030 | return sig.ret.clone(); |
| 1031 | } |
| 1032 | let mut bound: HashMap<String, Nim> = HashMap::new(); |
| 1033 | for (decl, actual) in sig.params.iter().zip(args) { |
| 1034 | if let Some(a) = actual { |
| 1035 | Self::unify(decl, a, &sig.generics, &mut bound); |
| 1036 | } |
| 1037 | } |
| 1038 | Self::subst(&sig.ret, &bound) |
| 1039 | } |
| 1040 | |
| 1041 | fn unify(decl: &Nim, actual: &Nim, params: &[String], out: &mut HashMap<String, Nim>) { |
| 1042 | match (decl, actual) { |
| 1043 | (Nim::Named(n, da), _) if params.iter().any(|p| p == n) && da.is_empty() => { |
| 1044 | out.entry(n.clone()).or_insert_with(|| actual.clone()); |
| 1045 | } |
| 1046 | (Nim::Named(_, da), Nim::Named(_, aa)) if da.len() == aa.len() => { |
| 1047 | for (d, a) in da.iter().zip(aa) { |
| 1048 | Self::unify(d, a, params, out); |
| 1049 | } |
| 1050 | } |
| 1051 | (Nim::Seq(d), Nim::Seq(a)) |
| 1052 | | (Nim::OpenArray(d), Nim::OpenArray(a)) |
| 1053 | | (Nim::Seq(d), Nim::OpenArray(a)) |
| 1054 | | (Nim::OpenArray(d), Nim::Seq(a)) |
| 1055 | | (Nim::Var(d), Nim::Var(a)) |
| 1056 | | (Nim::Array(_, d), Nim::Array(_, a)) => Self::unify(d, a, params, out), |
| 1057 | (Nim::Var(d), a) => Self::unify(d, a, params, out), |
| 1058 | (d, Nim::Var(a)) => Self::unify(d, a, params, out), |
| 1059 | (Nim::Tuple(d), Nim::Tuple(a)) if d.len() == a.len() => { |
| 1060 | for (d, a) in d.iter().zip(a) { |
| 1061 | Self::unify(d, a, params, out); |
| 1062 | } |
| 1063 | } |
| 1064 | _ => {} |
| 1065 | } |
| 1066 | } |
| 1067 | |
| 1068 | fn subst(t: &Nim, m: &HashMap<String, Nim>) -> Nim { |
| 1069 | match t { |
| 1070 | Nim::Named(n, a) if a.is_empty() => m.get(n).cloned().unwrap_or_else(|| t.clone()), |
| 1071 | Nim::Named(n, a) => { |
| 1072 | Nim::Named(n.clone(), a.iter().map(|x| Self::subst(x, m)).collect()) |
| 1073 | } |
| 1074 | Nim::Seq(e) => Nim::Seq(Box::new(Self::subst(e, m))), |
| 1075 | Nim::OpenArray(e) => Nim::OpenArray(Box::new(Self::subst(e, m))), |
| 1076 | Nim::Array(n, e) => Nim::Array(*n, Box::new(Self::subst(e, m))), |
| 1077 | Nim::Var(e) => Nim::Var(Box::new(Self::subst(e, m))), |
| 1078 | Nim::Tuple(ts) => Nim::Tuple(ts.iter().map(|x| Self::subst(x, m)).collect()), |
| 1079 | other => other.clone(), |
| 1080 | } |
| 1081 | } |
| 1082 | |
| 1083 | /// Whether a type mentions a type parameter that is in scope here. Such a |
| 1084 | /// type cannot be used as a Nim annotation at an instantiation site: Nim |
| 1085 | /// infers it, and writing `T` would name something that is not bound. |
| 1086 | fn mentions_type_param(&self, t: &Nim) -> bool { |
| 1087 | match t { |
| 1088 | Nim::Named(n, a) => { |
| 1089 | self.fn_generics.iter().any(|g| g == n) |
| 1090 | || a.iter().any(|x| self.mentions_type_param(x)) |
| 1091 | } |
| 1092 | Nim::Seq(e) | Nim::OpenArray(e) | Nim::Var(e) | Nim::Array(_, e) => { |
| 1093 | self.mentions_type_param(e) |
| 1094 | } |
| 1095 | Nim::Tuple(ts) => ts.iter().any(|x| self.mentions_type_param(x)), |
| 1096 | Nim::Proc(a, r) => { |
| 1097 | a.iter().any(|x| self.mentions_type_param(x)) || self.mentions_type_param(r) |
| 1098 | } |
| 1099 | _ => false, |
| 1100 | } |
| 1101 | } |
| 1102 | |
| Lower the `log` facade, and add explicit enum discriminants 12c0a01 nandithebull 6h ago | 1103 | /// The Nim name of a `log::Level` written as a path. |
| 1104 | fn log_level_of(&mut self, e: &Expr) -> Result<String, String> { |
| 1105 | let Expr::Path(p) = e else { |
| 1106 | return Err("a log level must be written as `Level::Info`".into()); |
| 1107 | }; |
| 1108 | let last = path_name(&p.path); |
| 1109 | Ok(match last.as_str() { |
| 1110 | "Error" => "rsLvlError", |
| 1111 | "Warn" => "rsLvlWarn", |
| 1112 | "Info" => "rsLvlInfo", |
| 1113 | "Debug" => "rsLvlDebug", |
| 1114 | "Trace" => "rsLvlTrace", |
| 1115 | other => return Err(format!("`Level::{other}` is not a log level")), |
| 1116 | } |
| 1117 | .to_string()) |
| 1118 | } |
| 1119 | |
| Add generics; transpile the part of cosmic-theme that is reachable ff34e1b nandithebull 7h ago | 1120 | /// `[T, U]`, or empty. |
| 1121 | fn gen_list(params: &[String]) -> String { |
| 1122 | if params.is_empty() { |
| 1123 | String::new() |
| 1124 | } else { |
| 1125 | format!("[{}]", params.join(", ")) |
| 1126 | } |
| 1127 | } |
| 1128 | |
| Add closures and unsafe; base16ct's lower.rs and upper.rs go through 0a375d8 nandithebull 9h ago | 1129 | /// The Nim name for a function, qualified by its module. |
| 1130 | fn fn_name(&self, module: &str, name: &str) -> String { |
| 1131 | if module.is_empty() { |
| 1132 | ident(name) |
| 1133 | } else { |
| 1134 | format!("{}_{}", module, ident(name)) |
| 1135 | } |
| 1136 | } |
| 1137 | |
| 1138 | /// Resolve a call path to the module and name it refers to: an explicit |
| 1139 | /// `mixed::decode`, then the current module, then the crate root. |
| 1140 | fn resolve_fn(&self, path: &syn::Path) -> Option<(String, String)> { |
| 1141 | let segs: Vec<String> = path.segments.iter().map(|s| s.ident.to_string()).collect(); |
| 1142 | let last = segs.last()?.clone(); |
| 1143 | if segs.len() >= 2 { |
| 1144 | let q = &segs[segs.len() - 2]; |
| 1145 | if self.fns.contains_key(&(q.clone(), last.clone())) { |
| 1146 | return Some((q.clone(), last)); |
| 1147 | } |
| 1148 | } |
| 1149 | let imported = self.use_map.get(&last).cloned(); |
| 1150 | for m in [Some(self.cur_mod.clone()), imported, Some(String::new())] |
| 1151 | .into_iter() |
| 1152 | .flatten() |
| 1153 | { |
| 1154 | if self.fns.contains_key(&(m.clone(), last.clone())) { |
| 1155 | return Some((m, last)); |
| 1156 | } |
| 1157 | } |
| 1158 | None |
| 1159 | } |
| 1160 | |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 1161 | /// The Nim `proc` head for a Rust signature, used both for the forward |
| 1162 | /// declaration and for the definition, so the two cannot drift apart. |
| 1163 | fn head_of( |
| 1164 | &self, |
| 1165 | name: &str, |
| 1166 | sig: &syn::Signature, |
| 1167 | recv: Option<&Nim>, |
| 1168 | ) -> Result<String, String> { |
| 1169 | let (ptys, ret) = self.signature(sig)?; |
| Add generics; transpile the part of cosmic-theme that is reachable ff34e1b nandithebull 7h ago | 1170 | // A method inside `impl<T> Foo<T>` is generic in the impl's |
| 1171 | // parameters as well as its own. |
| 1172 | let mut params = self.impl_generics.clone(); |
| 1173 | for g in Self::generics_of(&sig.generics) { |
| 1174 | if !params.contains(&g) { |
| 1175 | params.push(g); |
| 1176 | } |
| 1177 | } |
| 1178 | let gens = Self::gen_list(¶ms); |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 1179 | let mut parts = Vec::new(); |
| 1180 | if let Some(self_ty) = recv { |
| 1181 | let mutable = matches!( |
| 1182 | sig.inputs.first(), |
| 1183 | Some(FnArg::Receiver(r)) |
| 1184 | if matches!(&r.kind, syn::ReceiverKind::Reference(_, _, m) if m.is_some()) |
| 1185 | ); |
| 1186 | let t = if mutable { Nim::Var(Box::new(self_ty.clone())) } else { self_ty.clone() }; |
| 1187 | parts.push(format!("self: {}", t.render())); |
| 1188 | } |
| 1189 | let typed: Vec<&syn::PatType> = sig |
| 1190 | .inputs |
| 1191 | .iter() |
| 1192 | .filter_map(|a| match a { |
| 1193 | FnArg::Typed(t) => Some(t), |
| 1194 | _ => None, |
| 1195 | }) |
| 1196 | .collect(); |
| 1197 | for (i, (p, t)) in typed.iter().zip(ptys.iter()).enumerate() { |
| 1198 | let pname = match &*p.pat { |
| 1199 | Pat::Ident(id) => id.ident.to_string(), |
| 1200 | Pat::Wild(_) => format!("unused{}", parts.len()), |
| 1201 | _ => return Err("only plain identifier parameters are supported".into()), |
| 1202 | }; |
| 1203 | let _ = i; |
| 1204 | parts.push(format!("{}: {}", ident(&pname), t.render())); |
| 1205 | } |
| 1206 | Ok(if ret == Nim::Unit { |
| Add generics; transpile the part of cosmic-theme that is reachable ff34e1b nandithebull 7h ago | 1207 | format!("proc {}*{}({})", ident(name), gens, parts.join(", ")) |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 1208 | } else { |
| Add generics; transpile the part of cosmic-theme that is reachable ff34e1b nandithebull 7h ago | 1209 | format!( |
| 1210 | "proc {}*{}({}): {}", |
| 1211 | ident(name), |
| 1212 | gens, |
| 1213 | parts.join(", "), |
| 1214 | ret.render() |
| 1215 | ) |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 1216 | }) |
| 1217 | } |
| 1218 | |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 1219 | fn signature(&self, sig: &syn::Signature) -> Result<(Vec<Nim>, Nim), String> { |
| Add closures and unsafe; base16ct's lower.rs and upper.rs go through 0a375d8 nandithebull 9h ago | 1220 | // `unsafe fn` marks a contract for callers; it does not change what |
| 1221 | // the body means, so it lowers like any other proc. |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 1222 | if sig.asyncness.is_some() { |
| 1223 | return Err(format!("`async fn {}`: Nim has no equivalent", sig.ident)); |
| 1224 | } |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 1225 | // Lifetime parameters carry no runtime meaning and Nim is GC'd, so |
| Add generics; transpile the part of cosmic-theme that is reachable ff34e1b nandithebull 7h ago | 1226 | // they disappear. Type parameters become Nim generic parameters. |
| 1227 | // Const parameters have no Nim equivalent and are still rejected. |
| 1228 | if sig.generics.params.iter().any(|p| matches!(p, syn::GenericParam::Const(_))) { |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 1229 | return Err(format!( |
| Add generics; transpile the part of cosmic-theme that is reachable ff34e1b nandithebull 7h ago | 1230 | "`fn {}` has a const generic parameter, which Nim has no \ |
| 1231 | equivalent for", |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 1232 | sig.ident |
| 1233 | )); |
| 1234 | } |
| 1235 | let mut params = Vec::new(); |
| 1236 | for a in &sig.inputs { |
| 1237 | if let FnArg::Typed(t) = a { |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 1238 | params.push(self.map_ty(&t.ty)?); |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 1239 | } |
| 1240 | } |
| 1241 | let ret = match &sig.output { |
| 1242 | ReturnType::Default => Nim::Unit, |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 1243 | // A returned `&[T]` is a borrow of the caller's buffer, so it |
| 1244 | // stays an `openArray` view. Only an owned type (`Vec<T>`) becomes |
| 1245 | // a `seq`, which `owned()` would do to both. |
| 1246 | ReturnType::Type(_, t) => { |
| 1247 | let n = self.map_ty(t)?; |
| 1248 | if returns_borrow(t) { n } else { n.owned() } |
| 1249 | } |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 1250 | }; |
| 1251 | Ok((params, ret)) |
| 1252 | } |
| 1253 | |
| 1254 | // --------------------------------------------------------------- items |
| 1255 | |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 1256 | /// Emit the type definitions only: they must precede every signature. |
| 1257 | fn item_types(&mut self, item: &Item) -> Result<(), String> { |
| 1258 | if !self.cfg_keeps(item_attrs(item))? { |
| 1259 | return Ok(()); |
| 1260 | } |
| 1261 | match item { |
| 1262 | Item::Struct(_) | Item::Enum(_) | Item::Const(_) => self.item_inner(item), |
| Lower `bitflags!` directly, checked against the real crate af6e50f nandithebull 7h ago | 1263 | Item::Macro(m) if path_name(&m.mac.path) == "bitflags" => self.item_inner(item), |
| Lower `extern "C"` blocks to Nim importc; do not transpile libc 7db7991 nandithebull 6h ago | 1264 | Item::ForeignMod(_) => self.item_inner(item), |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 1265 | Item::Mod(m) if m.content.is_some() => { |
| 1266 | let items = m.content.as_ref().map(|(_, i)| i.clone()).unwrap_or_default(); |
| 1267 | for i in &items { |
| 1268 | self.item_types(i)?; |
| 1269 | } |
| 1270 | Ok(()) |
| 1271 | } |
| 1272 | _ => Ok(()), |
| 1273 | } |
| 1274 | } |
| 1275 | |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 1276 | fn item(&mut self, item: &Item) -> Result<(), String> { |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 1277 | if !self.cfg_keeps(item_attrs(item))? { |
| 1278 | return Ok(()); |
| 1279 | } |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 1280 | // Types were emitted in their own pass. |
| 1281 | if matches!(item, Item::Struct(_) | Item::Enum(_) | Item::Const(_)) { |
| 1282 | return Ok(()); |
| 1283 | } |
| Lower `extern "C"` blocks to Nim importc; do not transpile libc 7db7991 nandithebull 6h ago | 1284 | if matches!(item, Item::Macro(m) if path_name(&m.mac.path) == "bitflags") |
| 1285 | || matches!(item, Item::ForeignMod(_)) |
| 1286 | { |
| Lower `bitflags!` directly, checked against the real crate af6e50f nandithebull 7h ago | 1287 | return Ok(()); // emitted with the types |
| 1288 | } |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 1289 | self.item_inner(item) |
| 1290 | } |
| 1291 | |
| 1292 | fn item_inner(&mut self, item: &Item) -> Result<(), String> { |
| Fail when nothing was translated, not just when the file is empty 0777223 nandithebull 8h ago | 1293 | if !matches!(item, Item::Use(_) | Item::ExternCrate(_) | Item::Mod(_) | Item::Type(_)) { |
| 1294 | self.emitted += 1; |
| 1295 | } |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 1296 | match item { |
| Add closures and unsafe; base16ct's lower.rs and upper.rs go through 0a375d8 nandithebull 9h ago | 1297 | Item::Fn(f) => { |
| 1298 | let nim = self.fn_name(&self.cur_mod, &f.sig.ident.to_string()); |
| 1299 | self.func_named(&nim, &f.sig, &f.block, None) |
| 1300 | } |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 1301 | Item::Struct(s) => { |
| 1302 | let name = s.ident.to_string(); |
| 1303 | let fields = self.structs[&name].clone(); |
| Add generics; transpile the part of cosmic-theme that is reachable ff34e1b nandithebull 7h ago | 1304 | let g = Self::gen_list(self.type_generics.get(&name).map(|v| &v[..]).unwrap_or(&[])); |
| 1305 | self.line(&format!("type {}*{} = object", ident(&name), g)); |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 1306 | self.indent += 1; |
| 1307 | if fields.is_empty() { |
| 1308 | self.line("discard"); |
| 1309 | } |
| 1310 | for (fname, fty) in &fields { |
| 1311 | self.line(&format!("{}*: {}", ident(fname), fty.render())); |
| 1312 | } |
| 1313 | self.indent -= 1; |
| 1314 | self.blank(); |
| 1315 | Ok(()) |
| 1316 | } |
| Lower `bitflags!` directly, checked against the real crate af6e50f nandithebull 7h ago | 1317 | Item::Macro(m) if path_name(&m.mac.path) == "bitflags" => self.emit_bitflags(&m.mac), |
| Expand `macro_rules!` rather than translating it to a Nim template 04eb29f nandithebull 6h ago | 1318 | Item::Macro(m) if path_name(&m.mac.path) == "macro_rules" => Ok(()), |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 1319 | Item::Type(_) => Ok(()), // expanded at every use site |
| Add associated types and consts, and test whether the blocker stack bottoms out 8354895 nandithebull 7h ago | 1320 | Item::Trait(t) => { |
| 1321 | // We do not model trait resolution, so a declaration generates |
| 1322 | // nothing and a use that needed it is rejected where it |
| 1323 | // appears. A *default body*, though, is code: dropping it |
| 1324 | // would silently remove a method the impls inherit. |
| 1325 | for it in &t.items { |
| 1326 | if let syn::TraitItem::Fn(f) = it { |
| 1327 | if f.default.is_some() { |
| 1328 | return Err(format!( |
| 1329 | "`trait {}` gives `{}` a default body; trait \ |
| 1330 | resolution is not modelled, so that body has no \ |
| 1331 | impl to be emitted into and dropping it would \ |
| 1332 | remove code", |
| 1333 | t.ident, f.sig.ident |
| 1334 | )); |
| 1335 | } |
| 1336 | } |
| 1337 | } |
| 1338 | Ok(()) |
| 1339 | } |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 1340 | Item::Enum(e) => { |
| 1341 | let def = self.enums[&e.ident.to_string()].clone(); |
| 1342 | self.emit_enum(&def); |
| 1343 | Ok(()) |
| 1344 | } |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 1345 | Item::Const(c) => { |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 1346 | let t = self.map_ty(&c.ty)?.owned(); |
| Transpile a second crate, adler2, to test whether any of this generalises 5fdd5be nandithebull 8h ago | 1347 | // The annotation types the initialiser, exactly as it does for |
| 1348 | // a `let`: `const MOD: u32 = 65521` is a u32 literal. |
| 1349 | let v = self.expr_at(&c.expr, Some(&t))?; |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 1350 | self.bind(&c.ident.to_string(), t.clone()); |
| Transpile a second crate, adler2, to test whether any of this generalises 5fdd5be nandithebull 8h ago | 1351 | // Only a top-level const is exported; `*` on a local is not |
| 1352 | // Nim syntax. |
| 1353 | let star = if self.indent == 0 { "*" } else { "" }; |
| 1354 | let line = format!( |
| 1355 | "const {}{}: {} = {}", |
| 1356 | ident(&c.ident.to_string()), |
| 1357 | star, |
| 1358 | t.render(), |
| 1359 | v.code |
| 1360 | ); |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 1361 | self.line(&line); |
| Transpile a second crate, adler2, to test whether any of this generalises 5fdd5be nandithebull 8h ago | 1362 | if self.indent == 0 { |
| 1363 | self.blank(); |
| 1364 | } |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 1365 | Ok(()) |
| 1366 | } |
| 1367 | Item::Impl(im) => { |
| Add generics; transpile the part of cosmic-theme that is reachable ff34e1b nandithebull 7h ago | 1368 | let outer_g = |
| 1369 | std::mem::replace(&mut self.impl_generics, Self::generics_of(&im.generics)); |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 1370 | let self_ty = self.map_ty(&im.self_ty)?; |
| Transpile a second crate, adler2, to test whether any of this generalises 5fdd5be nandithebull 8h ago | 1371 | let outer = self.self_ty.replace(self_ty.clone()); |
| 1372 | let r = self.impl_body(im, &self_ty); |
| 1373 | self.self_ty = outer; |
| Add generics; transpile the part of cosmic-theme that is reachable ff34e1b nandithebull 7h ago | 1374 | self.impl_generics = outer_g; |
| Transpile a second crate, adler2, to test whether any of this generalises 5fdd5be nandithebull 8h ago | 1375 | r |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 1376 | } |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 1377 | // `use` and `extern crate` are resolution directives with no Nim |
| 1378 | // analogue once everything is one module. |
| 1379 | Item::Use(_) | Item::ExternCrate(_) => Ok(()), |
| Lower `extern "C"` blocks to Nim importc; do not transpile libc 7db7991 nandithebull 6h ago | 1380 | Item::ForeignMod(f) => self.foreign_mod(f), |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 1381 | Item::Mod(m) if m.content.is_some() => { |
| 1382 | // An inline `mod` is flattened; Nim has no nested modules in a |
| 1383 | // single file. |
| 1384 | let items = m.content.as_ref().map(|(_, i)| i.clone()).unwrap_or_default(); |
| 1385 | for i in &items { |
| 1386 | self.item(i)?; |
| 1387 | } |
| 1388 | Ok(()) |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 1389 | } |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 1390 | Item::Mod(m) => { |
| 1391 | // Satisfied if that file was passed in too; everything is one |
| 1392 | // Nim module, so the declaration itself emits nothing. |
| 1393 | if self.modules.iter().any(|x| *x == m.ident.to_string()) { |
| 1394 | return Ok(()); |
| 1395 | } |
| 1396 | Err(format!( |
| 1397 | "`mod {};` refers to another file that was not passed to \ |
| 1398 | rustnim; add it to the input list", |
| 1399 | m.ident |
| 1400 | )) |
| 1401 | } |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 1402 | other => Err(format!("unsupported item: {}", item_kind(other))), |
| 1403 | } |
| 1404 | } |
| 1405 | |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 1406 | /// `None` carries no type of its own, so Nim needs the `Option[T]` named. |
| 1407 | fn none_of(&self, expect: Option<&Nim>) -> String { |
| 1408 | match expect { |
| 1409 | Some(Nim::Named(n, a)) if n == "Option" && a.len() == 1 => { |
| 1410 | format!("rsNone[{}]()", a[0].render()) |
| 1411 | } |
| 1412 | _ => "rsNone()".to_string(), |
| 1413 | } |
| 1414 | } |
| 1415 | |
| Transpile a second crate, adler2, to test whether any of this generalises 5fdd5be nandithebull 8h ago | 1416 | fn impl_body(&mut self, im: &syn::ItemImpl, self_ty: &Nim) -> Result<(), String> { |
| 1417 | if let Some((path, _)) = &im.trait_ { |
| 1418 | let tr = path_name(path); |
| 1419 | if im.items.is_empty() { |
| 1420 | return Ok(()); |
| 1421 | } |
| 1422 | if is_fmt_trait(&tr) { |
| 1423 | let syn::ImplItem::Fn(m) = &im.items[0] else { |
| 1424 | return Err(format!("unsupported item in `impl {tr}`")); |
| 1425 | }; |
| 1426 | return self.fmt_impl(&tr, self_ty, &m.sig, &m.block); |
| 1427 | } |
| 1428 | if tr == "From" { |
| 1429 | let syn::ImplItem::Fn(m) = &im.items[0] else { |
| 1430 | return Err("`impl From` must contain `fn from`".into()); |
| 1431 | }; |
| 1432 | let name = { |
| 1433 | let (params, _) = self.signature(&m.sig)?; |
| 1434 | let src = params.first().cloned().ok_or("`fn from` takes one argument")?; |
| 1435 | self.from_impls[&(type_name(&src), type_name(self_ty))].clone() |
| 1436 | }; |
| 1437 | return self.func_named(&name, &m.sig, &m.block, None); |
| 1438 | } |
| 1439 | let tyname = type_name(self_ty); |
| 1440 | for it in &im.items { |
| Add associated types and consts, and test whether the blocker stack bottoms out 8354895 nandithebull 7h ago | 1441 | if let syn::ImplItem::Const(c) = it { |
| 1442 | self.assoc_const(&tyname, c)?; |
| 1443 | continue; |
| 1444 | } |
| 1445 | if matches!(it, syn::ImplItem::Type(_)) { |
| 1446 | continue; // a type binding emits nothing |
| 1447 | } |
| Transpile a second crate, adler2, to test whether any of this generalises 5fdd5be nandithebull 8h ago | 1448 | let syn::ImplItem::Fn(m) = it else { |
| Add associated types and consts, and test whether the blocker stack bottoms out 8354895 nandithebull 7h ago | 1449 | return Err(format!( |
| 1450 | "unsupported item in `impl {tr}`: only `fn`, `type` and \ |
| 1451 | `const` are implemented" |
| 1452 | )); |
| Transpile a second crate, adler2, to test whether any of this generalises 5fdd5be nandithebull 8h ago | 1453 | }; |
| 1454 | let recv = if takes_self(&m.sig) { Some(self_ty.clone()) } else { None }; |
| 1455 | let nim = trait_method_name(&tyname, &tr, &m.sig.ident.to_string()); |
| 1456 | self.func_named(&nim, &m.sig, &m.block, recv)?; |
| 1457 | } |
| 1458 | return Ok(()); |
| 1459 | } |
| Add associated types and consts, and test whether the blocker stack bottoms out 8354895 nandithebull 7h ago | 1460 | let tyname = type_name(self_ty); |
| Transpile a second crate, adler2, to test whether any of this generalises 5fdd5be nandithebull 8h ago | 1461 | for it in &im.items { |
| 1462 | match it { |
| 1463 | syn::ImplItem::Fn(m) => { |
| 1464 | let recv = if takes_self(&m.sig) { Some(self_ty.clone()) } else { None }; |
| 1465 | let nim = self.fn_name(&self.cur_mod, &m.sig.ident.to_string()); |
| 1466 | self.func_named(&nim, &m.sig, &m.block, recv)?; |
| 1467 | } |
| Add associated types and consts, and test whether the blocker stack bottoms out 8354895 nandithebull 7h ago | 1468 | syn::ImplItem::Type(_) => {} |
| 1469 | syn::ImplItem::Const(c) => self.assoc_const(&tyname, c)?, |
| 1470 | _ => { |
| 1471 | return Err("only `fn`, `type` and `const` items are supported \ |
| 1472 | inside `impl`" |
| 1473 | .into()) |
| 1474 | } |
| Transpile a second crate, adler2, to test whether any of this generalises 5fdd5be nandithebull 8h ago | 1475 | } |
| 1476 | } |
| 1477 | Ok(()) |
| 1478 | } |
| 1479 | |
| Lower `extern "C"` blocks to Nim importc; do not transpile libc 7db7991 nandithebull 6h ago | 1480 | /// An `extern "C" { .. }` block: declarations of symbols someone else |
| 1481 | /// defines. Nim's `importc` is the same statement, and both are bound by |
| 1482 | /// the C ABI, so the two declarations describe one symbol rather than one |
| 1483 | /// being a translation of the other. |
| 1484 | fn foreign_mod(&mut self, f: &syn::ItemForeignMod) -> Result<(), String> { |
| 1485 | let abi = f |
| 1486 | .abi |
| 1487 | .name |
| 1488 | .as_ref() |
| 1489 | .map(|s| s.value()) |
| 1490 | .unwrap_or_else(|| "C".into()); |
| 1491 | if abi != "C" { |
| 1492 | return Err(format!( |
| 1493 | "`extern \"{abi}\"` is not the C ABI; only that one has a Nim \ |
| 1494 | equivalent" |
| 1495 | )); |
| 1496 | } |
| 1497 | // A const-qualified C pointer needs a type whose C spelling carries |
| 1498 | // the `const`; Nim has no such type built in, so one is declared per |
| 1499 | // element type actually used. |
| 1500 | let mut needed: Vec<Nim> = Vec::new(); |
| 1501 | for it in &f.items { |
| 1502 | if let syn::ForeignItem::Fn(fi) = it { |
| 1503 | let (params, ret) = self.signature(&fi.sig)?; |
| 1504 | for t in params.iter().chain(std::iter::once(&ret)) { |
| 1505 | if let Nim::ConstPtr(inner) = t { |
| 1506 | if !matches!(&**inner, Nim::Prim(p) if p == "void") |
| 1507 | && !needed.contains(t) |
| 1508 | { |
| 1509 | needed.push(t.clone()); |
| 1510 | } |
| 1511 | } |
| 1512 | } |
| 1513 | } |
| 1514 | } |
| 1515 | for t in &needed { |
| 1516 | let Nim::ConstPtr(inner) = t else { continue }; |
| 1517 | let alias = ty::const_ptr_alias(inner); |
| 1518 | if !self.const_ptrs.insert(alias.clone()) { |
| 1519 | continue; |
| 1520 | } |
| 1521 | let c = ty::c_spelling(inner).ok_or_else(|| { |
| 1522 | format!( |
| 1523 | "`*const {}` has no C spelling we know, so a const-qualified \ |
| 1524 | declaration cannot be emitted for it", |
| 1525 | inner.render() |
| 1526 | ) |
| 1527 | })?; |
| 1528 | self.line(&format!( |
| 1529 | "type {}* {{.importc: \"const {} *\", nodecl.}} = distinct pointer", |
| 1530 | alias, c |
| 1531 | )); |
| 1532 | } |
| 1533 | |
| 1534 | for it in &f.items { |
| 1535 | match it { |
| 1536 | syn::ForeignItem::Fn(fi) => { |
| 1537 | if fi.sig.variadic.is_some() { |
| 1538 | return Err(format!( |
| 1539 | "`{}` is variadic; Nim needs `varargs` with a fixed \ |
| 1540 | calling shape, which this does not give us", |
| 1541 | fi.sig.ident |
| 1542 | )); |
| 1543 | } |
| 1544 | let name = fi.sig.ident.to_string(); |
| 1545 | let head = self.head_of(&name, &fi.sig, None)?; |
| 1546 | // `importc` names the C symbol, so the Nim name may differ |
| 1547 | // from it without changing what is linked. |
| 1548 | self.line(&format!( |
| 1549 | "{} {{.importc: \"{}\", cdecl.}}", |
| 1550 | head, name |
| 1551 | )); |
| 1552 | let (params, ret) = self.signature(&fi.sig)?; |
| 1553 | self.fns.insert( |
| 1554 | (self.cur_mod.clone(), name.clone()), |
| 1555 | Sig { params, ret, generics: Vec::new() }, |
| 1556 | ); |
| 1557 | self.foreign.insert(name); |
| 1558 | } |
| 1559 | syn::ForeignItem::Static(st) => { |
| 1560 | let t = self.map_ty(&st.ty)?; |
| 1561 | let name = st.ident.to_string(); |
| 1562 | self.line(&format!( |
| 1563 | "var {}* {{.importc: \"{}\".}}: {}", |
| 1564 | ident(&name), |
| 1565 | name, |
| 1566 | t.render() |
| 1567 | )); |
| 1568 | self.bind(&name, t); |
| 1569 | } |
| 1570 | syn::ForeignItem::Type(_) => { |
| 1571 | // An opaque C type: Nim spells it as a distinct object. |
| 1572 | continue; |
| 1573 | } |
| 1574 | _ => return Err("unsupported item in an `extern` block".into()), |
| 1575 | } |
| 1576 | } |
| 1577 | self.blank(); |
| 1578 | Ok(()) |
| 1579 | } |
| 1580 | |
| Add associated types and consts, and test whether the blocker stack bottoms out 8354895 nandithebull 7h ago | 1581 | /// `const N: usize = 4;` inside an `impl`. Nim has no per-type constant |
| 1582 | /// namespace, so it becomes a module-level const named for both. |
| 1583 | fn assoc_const(&mut self, tyname: &str, c: &syn::ImplItemConst) -> Result<(), String> { |
| 1584 | let t = self.map_ty(&c.ty)?.owned(); |
| 1585 | let v = self.expr_at(&c.expr, Some(&t))?; |
| 1586 | let name = format!("{}_{}", tyname, c.ident); |
| 1587 | self.line(&format!("const {}*: {} = {}", ident(&name), t.render(), v.code)); |
| 1588 | self.blank(); |
| 1589 | self.assoc_consts |
| 1590 | .insert((tyname.to_string(), c.ident.to_string()), (ident(&name), t)); |
| 1591 | Ok(()) |
| 1592 | } |
| 1593 | |
| Transpile a second crate, adler2, to test whether any of this generalises 5fdd5be nandithebull 8h ago | 1594 | /// The type an operator impl declares for its right-hand operand. |
| 1595 | fn op_param(&self, t: &Option<Nim>, op: &str) -> Option<Nim> { |
| 1596 | let n = type_name(t.as_ref()?); |
| 1597 | let sig = self.methods.get(&(n, op_method(op).to_string()))?; |
| 1598 | sig.params.get(1).cloned().map(|t| t.unvar()) |
| 1599 | } |
| 1600 | |
| 1601 | /// The proc implementing `op` for a user type, if there is one. |
| 1602 | fn op_proc(&self, t: &Option<Nim>, op: &str) -> Option<String> { |
| 1603 | let n = type_name(t.as_ref()?); |
| 1604 | let tr = OPERATOR_TRAITS.iter().find(|(_, o)| *o == op)?.0; |
| 1605 | if self.op_impls.contains_key(&(n.clone(), op.to_string())) { |
| 1606 | Some(trait_method_name(&n, tr, OP_METHOD.iter().find(|(o, _)| *o == op)?.1)) |
| 1607 | } else { |
| 1608 | None |
| 1609 | } |
| 1610 | } |
| 1611 | |
| Lower `bitflags!` directly, checked against the real crate af6e50f nandithebull 7h ago | 1612 | /// Register a `bitflags!` type's operations so call sites resolve. |
| 1613 | fn collect_bitflags(&mut self, mac: &syn::Macro) -> Result<(), String> { |
| 1614 | let input: crate::macros::BitflagsInput = mac |
| 1615 | .parse_body() |
| 1616 | .map_err(|e| format!("`bitflags!`: {e}"))?; |
| 1617 | for def in &input.0 { |
| 1618 | let name = def.name.to_string(); |
| 1619 | let repr = self.map_ty(&def.repr)?; |
| 1620 | if !repr.is_integer() { |
| 1621 | return Err(format!("`bitflags! {name}` needs an integer representation")); |
| 1622 | } |
| 1623 | let me = Nim::Named(name.clone(), vec![]); |
| 1624 | let b = Nim::Prim("bool".into()); |
| 1625 | self.structs |
| 1626 | .insert(name.clone(), vec![("bitsField".into(), repr.clone())]); |
| 1627 | self.type_generics.insert(name.clone(), Vec::new()); |
| 1628 | |
| 1629 | let mut m = |n: &str, params: Vec<Nim>, ret: Nim, nim: String| { |
| 1630 | self.methods.insert( |
| 1631 | (name.clone(), n.to_string()), |
| 1632 | Sig { params, ret, generics: Vec::new() }, |
| 1633 | ); |
| 1634 | self.statics.insert((name.clone(), n.to_string()), nim); |
| 1635 | }; |
| 1636 | let s1 = vec![me.clone()]; |
| 1637 | let s2 = vec![me.clone(), me.clone()]; |
| 1638 | let vs2 = vec![Nim::Var(Box::new(me.clone())), me.clone()]; |
| 1639 | m("bits", s1.clone(), repr.clone(), format!("{name}_bits")); |
| 1640 | m("is_empty", s1.clone(), b.clone(), format!("{name}_is_empty")); |
| 1641 | m("is_all", s1.clone(), b.clone(), format!("{name}_is_all")); |
| 1642 | m("contains", s2.clone(), b.clone(), format!("{name}_contains")); |
| 1643 | m("intersects", s2.clone(), b.clone(), format!("{name}_intersects")); |
| 1644 | for (rust, nim) in [ |
| 1645 | ("union", "union"), |
| 1646 | ("intersection", "intersection"), |
| 1647 | ("difference", "difference"), |
| 1648 | ("symmetric_difference", "symmetric_difference"), |
| 1649 | ] { |
| 1650 | m(rust, s2.clone(), me.clone(), format!("{name}_{nim}")); |
| 1651 | } |
| 1652 | for n in ["insert", "remove", "toggle"] { |
| 1653 | m(n, vs2.clone(), Nim::Unit, format!("{name}_{n}")); |
| 1654 | } |
| 1655 | m( |
| 1656 | "set", |
| 1657 | vec![Nim::Var(Box::new(me.clone())), me.clone(), b.clone()], |
| 1658 | Nim::Unit, |
| 1659 | format!("{name}_set"), |
| 1660 | ); |
| 1661 | m("empty", vec![], me.clone(), format!("{name}_empty")); |
| 1662 | m("all", vec![], me.clone(), format!("{name}_all")); |
| 1663 | m( |
| 1664 | "from_bits", |
| 1665 | vec![repr.clone()], |
| 1666 | Nim::Named("Option".into(), vec![me.clone()]), |
| 1667 | format!("{name}_from_bits"), |
| 1668 | ); |
| 1669 | m( |
| 1670 | "from_bits_truncate", |
| 1671 | vec![repr.clone()], |
| 1672 | me.clone(), |
| 1673 | format!("{name}_from_bits_truncate"), |
| 1674 | ); |
| 1675 | m("complement", s1.clone(), me.clone(), format!("{name}_complement")); |
| 1676 | |
| 1677 | // The operator forms, routed through the same dispatch that a |
| 1678 | // hand-written `impl BitOr` would use. |
| 1679 | for (op, trait_name, method) in [ |
| 1680 | ("|", "BitOr", "bitor"), |
| 1681 | ("&", "BitAnd", "bitand"), |
| 1682 | ("^", "BitXor", "bitxor"), |
| 1683 | ("-", "Sub", "sub"), |
| 1684 | ("not", "Not", "not"), |
| 1685 | ] { |
| 1686 | self.op_impls.insert((name.clone(), op.to_string()), ()); |
| 1687 | let params = if op == "not" { s1.clone() } else { s2.clone() }; |
| 1688 | self.methods.insert( |
| 1689 | (name.clone(), method.to_string()), |
| 1690 | Sig { params, ret: me.clone(), generics: Vec::new() }, |
| 1691 | ); |
| 1692 | let _ = trait_name; |
| 1693 | } |
| 1694 | self.bitflags.insert(name); |
| 1695 | } |
| 1696 | Ok(()) |
| 1697 | } |
| 1698 | |
| 1699 | /// Emit the Nim for a `bitflags!` type. See `src/macros.rs` for why this |
| 1700 | /// is lowered directly rather than by expanding the macro. |
| 1701 | fn emit_bitflags(&mut self, mac: &syn::Macro) -> Result<(), String> { |
| 1702 | let input: crate::macros::BitflagsInput = mac |
| 1703 | .parse_body() |
| 1704 | .map_err(|e| format!("`bitflags!`: {e}"))?; |
| 1705 | for def in &input.0 { |
| 1706 | let name = def.name.to_string(); |
| 1707 | let repr = self.map_ty(&def.repr)?; |
| 1708 | let r = repr.render(); |
| 1709 | |
| 1710 | self.line(&format!("type {name}* = object")); |
| 1711 | self.line(&format!(" bitsField*: {r}")); |
| 1712 | self.blank(); |
| 1713 | self.line(&format!("proc {name}_bits*(x: {name}): {r} = x.bitsField")); |
| 1714 | |
| 1715 | // The constants. A flag's value may name earlier flags, as |
| 1716 | // `const ALL = Self::READ.bits() | ..` does, so they are emitted |
| 1717 | // in order and each is in scope for the next. |
| 1718 | self.push_scope(); |
| 1719 | self.bind_static_type(&name, &repr); |
| 1720 | for (fname, value) in &def.flags { |
| 1721 | let v = self.expr_at(value, Some(&repr))?; |
| 1722 | self.line(&format!( |
| 1723 | "const {}{}* = {}(bitsField: {})", |
| 1724 | name, fname, name, v.code |
| 1725 | )); |
| 1726 | self.flag_consts |
| 1727 | .insert((name.clone(), fname.to_string()), format!("{name}{fname}")); |
| 1728 | } |
| 1729 | self.pop_scope(); |
| 1730 | |
| 1731 | let all: Vec<String> = def |
| 1732 | .flags |
| 1733 | .iter() |
| 1734 | .map(|(f, _)| format!("{name}{f}.bitsField")) |
| 1735 | .collect(); |
| 1736 | let all_bits = if all.is_empty() { |
| 1737 | format!("{}(0)", r) |
| 1738 | } else { |
| 1739 | all.join(" or ") |
| 1740 | }; |
| 1741 | self.blank(); |
| 1742 | self.line(&format!("const {name}AllBits: {r} = {all_bits}")); |
| 1743 | self.blank(); |
| 1744 | |
| 1745 | for l in [ |
| 1746 | format!("proc {name}_empty*(): {name} = {name}(bitsField: {r}(0))"), |
| 1747 | format!("proc {name}_all*(): {name} = {name}(bitsField: {name}AllBits)"), |
| 1748 | format!("proc {name}_is_empty*(x: {name}): bool = x.bitsField == {r}(0)"), |
| 1749 | format!("proc {name}_is_all*(x: {name}): bool = (x.bitsField and {name}AllBits) == {name}AllBits"), |
| 1750 | format!("proc {name}_contains*(a, b: {name}): bool = (a.bitsField and b.bitsField) == b.bitsField"), |
| 1751 | format!("proc {name}_intersects*(a, b: {name}): bool = (a.bitsField and b.bitsField) != {r}(0)"), |
| 1752 | format!("proc {name}_union*(a, b: {name}): {name} = {name}(bitsField: a.bitsField or b.bitsField)"), |
| 1753 | format!("proc {name}_intersection*(a, b: {name}): {name} = {name}(bitsField: a.bitsField and b.bitsField)"), |
| 1754 | format!("proc {name}_difference*(a, b: {name}): {name} = {name}(bitsField: a.bitsField and (not b.bitsField))"), |
| 1755 | format!("proc {name}_symmetric_difference*(a, b: {name}): {name} = {name}(bitsField: a.bitsField xor b.bitsField)"), |
| 1756 | // `!x` complements and then masks to `all()`, which is what |
| 1757 | // bitflags does and not what a plain `not` would give. |
| 1758 | format!("proc {name}_complement*(x: {name}): {name} = {name}(bitsField: (not x.bitsField) and {name}AllBits)"), |
| 1759 | format!("proc {name}_from_bits_truncate*(b: {r}): {name} = {name}(bitsField: b and {name}AllBits)"), |
| 1760 | format!("proc {name}_from_bits*(b: {r}): Option[{name}] ="), |
| 1761 | format!(" if (b and (not {name}AllBits)) != {r}(0): rsNone[{name}]() else: rsSome({name}(bitsField: b))"), |
| 1762 | format!("proc {name}_insert*(x: var {name}, o: {name}) = x.bitsField = x.bitsField or o.bitsField"), |
| 1763 | format!("proc {name}_remove*(x: var {name}, o: {name}) = x.bitsField = x.bitsField and (not o.bitsField)"), |
| 1764 | format!("proc {name}_toggle*(x: var {name}, o: {name}) = x.bitsField = x.bitsField xor o.bitsField"), |
| 1765 | format!("proc {name}_set*(x: var {name}, o: {name}, on: bool) ="), |
| 1766 | format!(" if on: {name}_insert(x, o) else: {name}_remove(x, o)"), |
| 1767 | format!("proc rsBitOr_{name}_bitor*(a, b: {name}): {name} = {name}_union(a, b)"), |
| 1768 | format!("proc rsBitAnd_{name}_bitand*(a, b: {name}): {name} = {name}_intersection(a, b)"), |
| 1769 | format!("proc rsBitXor_{name}_bitxor*(a, b: {name}): {name} = {name}_symmetric_difference(a, b)"), |
| 1770 | format!("proc rsSub_{name}_sub*(a, b: {name}): {name} = {name}_difference(a, b)"), |
| 1771 | format!("proc rsNot_{name}_not*(a: {name}): {name} = {name}_complement(a)"), |
| 1772 | ] { |
| 1773 | self.line(&l); |
| 1774 | } |
| 1775 | |
| 1776 | // Debug prints the set flag names, or `0x0` when empty -- again |
| 1777 | // matching the crate rather than a guess. |
| 1778 | self.line(&format!("proc rsDebug*(x: {name}): string =")); |
| 1779 | self.line(&format!(" result = \"{name}(\"")); |
| 1780 | self.line(" var first = true"); |
| 1781 | for (fname, _) in &def.flags { |
| 1782 | self.line(&format!( |
| 1783 | " if (x.bitsField and {name}{f}.bitsField) == {name}{f}.bitsField and {name}{f}.bitsField != {r}(0):", |
| 1784 | f = fname |
| 1785 | )); |
| 1786 | self.line(" if not first: result.add(\" | \")"); |
| 1787 | self.line(&format!(" result.add(\"{fname}\")")); |
| 1788 | self.line(" first = false"); |
| 1789 | } |
| 1790 | self.line(" if first: result.add(\"0x0\")"); |
| 1791 | self.line(" result.add(\")\")"); |
| 1792 | self.blank(); |
| 1793 | } |
| 1794 | Ok(()) |
| 1795 | } |
| 1796 | |
| 1797 | fn bind_static_type(&mut self, _name: &str, _repr: &Nim) {} |
| 1798 | |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 1799 | fn emit_enum(&mut self, def: &EnumDef) { |
| 1800 | let name = ident(&def.name); |
| Add generics; transpile the part of cosmic-theme that is reachable ff34e1b nandithebull 7h ago | 1801 | let g = Self::gen_list( |
| 1802 | self.type_generics.get(&def.name).map(|v| &v[..]).unwrap_or(&[]), |
| 1803 | ); |
| 1804 | if def.simple && !g.is_empty() { |
| 1805 | // A Nim `enum` cannot take parameters; an all-unit generic enum |
| 1806 | // has no payload to be generic in anyway, so this would be a |
| 1807 | // parameter that never appears. |
| 1808 | // Fall through to the object-variant form instead. |
| 1809 | } |
| 1810 | if def.simple && g.is_empty() { |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 1811 | // Every variant is a unit variant, so a plain Nim enum is an exact |
| 1812 | // fit: it compares, orders and `case`-checks like Rust's. |
| 1813 | self.line(&format!("type {name}* = enum")); |
| 1814 | self.indent += 1; |
| 1815 | for v in &def.variants { |
| Lower the `log` facade, and add explicit enum discriminants 12c0a01 nandithebull 6h ago | 1816 | match &v.discriminant { |
| 1817 | Some(d) => self.line(&format!("{} = {}", ident(&v.name), d)), |
| 1818 | None => self.line(&ident(&v.name)), |
| 1819 | } |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 1820 | } |
| 1821 | self.indent -= 1; |
| 1822 | self.blank(); |
| 1823 | self.line(&format!("proc rsDebug*(x: {name}): string =")); |
| 1824 | self.indent += 1; |
| 1825 | self.line("case x"); |
| 1826 | for v in &def.variants { |
| 1827 | self.line(&format!("of {}.{}: \"{}\"", name, ident(&v.name), v.name)); |
| 1828 | } |
| 1829 | self.indent -= 1; |
| 1830 | self.blank(); |
| 1831 | return; |
| 1832 | } |
| 1833 | |
| 1834 | // A data-carrying enum is a Nim object variant: one discriminant enum |
| 1835 | // plus a branch per variant. This is the same shape the prelude uses |
| 1836 | // for `Option` and `Result`. |
| 1837 | self.line("type"); |
| 1838 | self.indent += 1; |
| 1839 | self.line(&format!("{}Kind* = enum", name)); |
| 1840 | self.indent += 1; |
| 1841 | for v in &def.variants { |
| 1842 | self.line(&def.kind_ident(&v.name)); |
| 1843 | } |
| 1844 | self.indent -= 1; |
| 1845 | self.blank(); |
| Add generics; transpile the part of cosmic-theme that is reachable ff34e1b nandithebull 7h ago | 1846 | self.line(&format!("{}*{} = object", name, g)); |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 1847 | self.indent += 1; |
| 1848 | self.line(&format!("case kind*: {}Kind", name)); |
| 1849 | for v in &def.variants { |
| 1850 | if v.fields.is_empty() { |
| 1851 | self.line(&format!("of {}: discard", def.kind_ident(&v.name))); |
| 1852 | } else { |
| 1853 | self.line(&format!("of {}:", def.kind_ident(&v.name))); |
| 1854 | self.indent += 1; |
| 1855 | for (f, t) in &v.fields { |
| 1856 | self.line(&format!("{}*: {}", ident(f), t.render())); |
| 1857 | } |
| 1858 | self.indent -= 1; |
| 1859 | } |
| 1860 | } |
| 1861 | self.indent -= 2; |
| 1862 | self.blank(); |
| 1863 | |
| 1864 | for v in &def.variants { |
| 1865 | let args: Vec<String> = v |
| 1866 | .fields |
| 1867 | .iter() |
| 1868 | .enumerate() |
| 1869 | .map(|(i, (_, t))| format!("a{}: {}", i, t.render())) |
| 1870 | .collect(); |
| 1871 | let inits: Vec<String> = v |
| 1872 | .fields |
| 1873 | .iter() |
| 1874 | .enumerate() |
| 1875 | .map(|(i, (f, _))| format!("{}: a{}", ident(f), i)) |
| 1876 | .collect(); |
| 1877 | let mut all = vec![format!("kind: {}", def.kind_ident(&v.name))]; |
| 1878 | all.extend(inits); |
| Add generics; transpile the part of cosmic-theme that is reachable ff34e1b nandithebull 7h ago | 1879 | let ret = format!("{}{}", name, g); |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 1880 | self.line(&format!( |
| Add generics; transpile the part of cosmic-theme that is reachable ff34e1b nandithebull 7h ago | 1881 | "proc {}*{}({}): {} = {}({})", |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 1882 | def.ctor_ident(&v.name), |
| Add generics; transpile the part of cosmic-theme that is reachable ff34e1b nandithebull 7h ago | 1883 | g, |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 1884 | args.join(", "), |
| Add generics; transpile the part of cosmic-theme that is reachable ff34e1b nandithebull 7h ago | 1885 | ret, |
| 1886 | ret, |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 1887 | all.join(", ") |
| 1888 | )); |
| 1889 | } |
| 1890 | self.blank(); |
| 1891 | |
| Add generics; transpile the part of cosmic-theme that is reachable ff34e1b nandithebull 7h ago | 1892 | self.line(&format!("proc rsDebug*{}(x: {}{}): string =", g, name, g)); |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 1893 | self.indent += 1; |
| 1894 | self.line("case x.kind"); |
| 1895 | for v in &def.variants { |
| 1896 | if v.fields.is_empty() { |
| 1897 | self.line(&format!("of {}: \"{}\"", def.kind_ident(&v.name), v.name)); |
| 1898 | } else { |
| 1899 | let parts: Vec<String> = v |
| 1900 | .fields |
| 1901 | .iter() |
| 1902 | .map(|(f, _)| format!("rsDebug(x.{})", ident(f))) |
| 1903 | .collect(); |
| 1904 | self.line(&format!( |
| 1905 | "of {}: \"{}(\" & {} & \")\"", |
| 1906 | def.kind_ident(&v.name), |
| 1907 | v.name, |
| 1908 | parts.join(" & \", \" & ") |
| 1909 | )); |
| 1910 | } |
| 1911 | } |
| 1912 | self.indent -= 1; |
| 1913 | self.blank(); |
| 1914 | } |
| 1915 | |
| Add generics; transpile the part of cosmic-theme that is reachable ff34e1b nandithebull 7h ago | 1916 | /// The concrete type an enum variant constructs, and the `[T]` list to |
| 1917 | /// spell at the constructor when the enum is generic. |
| 1918 | fn variant_type( |
| 1919 | &self, |
| 1920 | def: &EnumDef, |
| 1921 | expect: Option<&Nim>, |
| 1922 | ) -> Result<(Nim, String), String> { |
| 1923 | let params = self.type_generics.get(&def.name).cloned().unwrap_or_default(); |
| 1924 | if params.is_empty() { |
| 1925 | return Ok((Nim::Named(def.name.clone(), vec![]), String::new())); |
| 1926 | } |
| 1927 | match expect { |
| 1928 | Some(Nim::Named(n, a)) if *n == def.name && a.len() == params.len() => Ok(( |
| 1929 | Nim::Named(def.name.clone(), a.clone()), |
| 1930 | format!("[{}]", a.iter().map(|t| t.render()).collect::<Vec<_>>().join(", ")), |
| 1931 | )), |
| 1932 | _ => Err(format!( |
| 1933 | "`{}` is a variant of a generic enum, and its type parameters \ |
| 1934 | cannot be inferred here; annotate the binding or the return type", |
| 1935 | def.name |
| 1936 | )), |
| 1937 | } |
| 1938 | } |
| 1939 | |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 1940 | /// Resolve a Rust path like `Error::InvalidLength` or a bare `InvalidLength` |
| 1941 | /// to the enum that declares it. |
| 1942 | fn resolve_variant(&self, path: &syn::Path) -> Option<(EnumDef, String)> { |
| 1943 | let segs: Vec<String> = path.segments.iter().map(|s| s.ident.to_string()).collect(); |
| 1944 | let last = segs.last()?.clone(); |
| 1945 | if segs.len() >= 2 { |
| 1946 | if let Some(def) = self.enums.get(&segs[segs.len() - 2]) { |
| 1947 | if def.get(&last).is_some() { |
| 1948 | return Some((def.clone(), last)); |
| 1949 | } |
| 1950 | } |
| 1951 | } |
| 1952 | // Unqualified: only unambiguous if exactly one enum declares it. |
| 1953 | match self.variant_owner.get(&last) { |
| 1954 | Some(owners) if owners.len() == 1 => { |
| 1955 | let def = self.enums.get(&owners[0])?; |
| 1956 | Some((def.clone(), last)) |
| 1957 | } |
| 1958 | _ => None, |
| 1959 | } |
| 1960 | } |
| 1961 | |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 1962 | /// Lower `impl Display for T`'s `fn fmt` into a proc returning a string. |
| 1963 | /// |
| 1964 | /// Rust's `Formatter` is a sink that a `fmt` method writes into; the |
| 1965 | /// observable result of `{}` is exactly the bytes written. So the method |
| 1966 | /// becomes `proc rsDisplay(self: T): string` and every write through the |
| 1967 | /// formatter produces that string. A `fmt` body that does anything else |
| 1968 | /// with the formatter -- padding, precision, `debug_struct` -- is rejected, |
| 1969 | /// because those affect the output and this model does not carry them. |
| 1970 | /// The window an expression names, if it names one. |
| 1971 | fn window_of(&self, e: &Expr) -> Option<Alias> { |
| 1972 | match e { |
| 1973 | Expr::Path(p) => match self.lookup_alias(&path_name(&p.path)) { |
| 1974 | Some(a @ Alias::Window { .. }) => Some(a), |
| 1975 | _ => None, |
| 1976 | }, |
| 1977 | Expr::Reference(r) => self.window_of(&r.expr), |
| 1978 | Expr::Paren(p) => self.window_of(&p.expr), |
| 1979 | Expr::Unary(u) if matches!(u.op, UnOp::Deref(_)) => self.window_of(&u.expr), |
| 1980 | _ => None, |
| 1981 | } |
| 1982 | } |
| 1983 | |
| 1984 | /// Whether an expression is the `Formatter` parameter of the formatting |
| 1985 | /// impl currently being lowered. |
| 1986 | fn is_fmt_param(&self, e: &Expr) -> bool { |
| 1987 | let Some(f) = &self.fmt_param else { return false }; |
| 1988 | match e { |
| 1989 | Expr::Path(p) => path_name(&p.path) == *f, |
| 1990 | Expr::Reference(r) => self.is_fmt_param(&r.expr), |
| 1991 | Expr::Paren(p) => self.is_fmt_param(&p.expr), |
| 1992 | _ => false, |
| 1993 | } |
| 1994 | } |
| 1995 | |
| 1996 | fn fmt_impl( |
| 1997 | &mut self, |
| 1998 | tr: &str, |
| 1999 | self_ty: &Nim, |
| 2000 | sig: &syn::Signature, |
| 2001 | body: &syn::Block, |
| 2002 | ) -> Result<(), String> { |
| 2003 | let proc_name = fmt_proc(tr); |
| 2004 | // The formatter is the parameter after `self`. |
| 2005 | let f = sig |
| 2006 | .inputs |
| 2007 | .iter() |
| 2008 | .filter_map(|a| match a { |
| 2009 | FnArg::Typed(t) => match &*t.pat { |
| 2010 | Pat::Ident(i) => Some(i.ident.to_string()), |
| 2011 | _ => None, |
| 2012 | }, |
| 2013 | _ => None, |
| 2014 | }) |
| 2015 | .next() |
| 2016 | .ok_or("`fn fmt` needs a `Formatter` parameter")?; |
| 2017 | |
| 2018 | self.push_scope(); |
| 2019 | self.bind("self", self_ty.clone()); |
| 2020 | let saved = self.fmt_param.replace(f); |
| 2021 | let outer_ret = self.ret.replace(Nim::Prim("string".into())); |
| Add display.rs and the alloc half: all of base16ct now goes through afb2a6e nandithebull 9h ago | 2022 | // No assignment target: a formatter write *appends*, because a `fmt` |
| 2023 | // body may write repeatedly -- `UpperHex` writes once per byte in a |
| 2024 | // loop -- and assigning would keep only the last one. |
| 2025 | let outer_target = self.target.take(); |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 2026 | |
| 2027 | self.line(&format!( |
| 2028 | "proc {}*(self: {}): string =", |
| 2029 | proc_name, |
| 2030 | self_ty.render() |
| 2031 | )); |
| 2032 | self.indent += 1; |
| 2033 | let before = self.out.len(); |
| Add display.rs and the alloc half: all of base16ct now goes through afb2a6e nandithebull 9h ago | 2034 | let tail = self.block_body(body)?; |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 2035 | self.emit_tail(tail); |
| 2036 | if self.out.len() == before { |
| 2037 | self.line("discard"); |
| 2038 | } |
| 2039 | self.indent -= 1; |
| 2040 | |
| 2041 | self.target = outer_target; |
| 2042 | self.ret = outer_ret; |
| 2043 | self.fmt_param = saved; |
| 2044 | self.pop_scope(); |
| 2045 | self.blank(); |
| 2046 | Ok(()) |
| 2047 | } |
| 2048 | |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 2049 | fn func( |
| 2050 | &mut self, |
| 2051 | sig: &syn::Signature, |
| 2052 | body: &syn::Block, |
| 2053 | recv: Option<Nim>, |
| 2054 | ) -> Result<(), String> { |
| 2055 | let name = sig.ident.to_string(); |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 2056 | self.func_named(&name.clone(), sig, body, recv) |
| 2057 | } |
| 2058 | |
| 2059 | fn func_named( |
| 2060 | &mut self, |
| 2061 | name: &str, |
| 2062 | sig: &syn::Signature, |
| 2063 | body: &syn::Block, |
| 2064 | recv: Option<Nim>, |
| 2065 | ) -> Result<(), String> { |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 2066 | let (ptys, ret) = self.signature(sig)?; |
| 2067 | |
| 2068 | self.push_scope(); |
| 2069 | let mut rendered: Vec<String> = Vec::new(); |
| 2070 | |
| 2071 | if let Some(self_ty) = recv { |
| 2072 | // `&mut self` and `mut self` both mean the body may mutate the |
| 2073 | // receiver; only the former is observable by the caller, and a Nim |
| 2074 | // `var` parameter is the faithful spelling of that. |
| 2075 | let mutable = matches!( |
| 2076 | sig.inputs.first(), |
| 2077 | Some(FnArg::Receiver(r)) |
| 2078 | if matches!(&r.kind, syn::ReceiverKind::Reference(_, _, m) if m.is_some()) |
| 2079 | ); |
| 2080 | let t = if mutable { Nim::Var(Box::new(self_ty.clone())) } else { self_ty.clone() }; |
| 2081 | rendered.push(format!("self: {}", t.render())); |
| 2082 | self.bind("self", self_ty); |
| 2083 | } |
| 2084 | |
| 2085 | let typed: Vec<&syn::PatType> = sig |
| 2086 | .inputs |
| 2087 | .iter() |
| 2088 | .filter_map(|a| match a { |
| 2089 | FnArg::Typed(t) => Some(t), |
| 2090 | _ => None, |
| 2091 | }) |
| 2092 | .collect(); |
| 2093 | for (p, t) in typed.iter().zip(ptys.iter()) { |
| 2094 | let pname = match &*p.pat { |
| 2095 | Pat::Ident(i) => i.ident.to_string(), |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 2096 | // `fn from(_: Error) -> ..` — the parameter is unused, but Nim |
| 2097 | // still needs a name for it. |
| 2098 | Pat::Wild(_) => format!("unused{}", rendered.len()), |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 2099 | _ => return Err("only plain identifier parameters are supported".into()), |
| 2100 | }; |
| 2101 | rendered.push(format!("{}: {}", ident(&pname), t.render())); |
| 2102 | // Inside the body a `var T` parameter is used exactly like a `T`. |
| 2103 | self.bind(&pname, t.clone().owned()); |
| 2104 | } |
| 2105 | |
| Add generics; transpile the part of cosmic-theme that is reachable ff34e1b nandithebull 7h ago | 2106 | let mut gparams = self.impl_generics.clone(); |
| 2107 | for g in Self::generics_of(&sig.generics) { |
| 2108 | if !gparams.contains(&g) { |
| 2109 | gparams.push(g); |
| 2110 | } |
| 2111 | } |
| 2112 | let gens = Self::gen_list(&gparams); |
| 2113 | let outer_fg = std::mem::replace(&mut self.fn_generics, gparams.clone()); |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 2114 | let head = if ret == Nim::Unit { |
| Add generics; transpile the part of cosmic-theme that is reachable ff34e1b nandithebull 7h ago | 2115 | format!("proc {}*{}({}) =", ident(name), gens, rendered.join(", ")) |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 2116 | } else { |
| Add generics; transpile the part of cosmic-theme that is reachable ff34e1b nandithebull 7h ago | 2117 | format!( |
| 2118 | "proc {}*{}({}): {} =", |
| 2119 | ident(name), |
| 2120 | gens, |
| 2121 | rendered.join(", "), |
| 2122 | ret.render() |
| 2123 | ) |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 2124 | }; |
| 2125 | self.line(&head); |
| 2126 | self.indent += 1; |
| 2127 | let outer_ret = self.ret.replace(ret.clone()); |
| 2128 | |
| 2129 | // A Rust fn's trailing expression is its return value. Naming Nim's |
| 2130 | // implicit `result` as the target makes that true whether the tail is |
| 2131 | // a plain expression or an `if`/`match` with statement arms. |
| 2132 | let outer_target = if ret == Nim::Unit { |
| 2133 | self.target.take() |
| 2134 | } else { |
| 2135 | self.target.replace(("result".to_string(), Some(ret.clone()))) |
| 2136 | }; |
| 2137 | let before = self.out.len(); |
| 2138 | let tail = self.block_body_at(body, Some(&ret))?; |
| 2139 | self.target = outer_target; |
| 2140 | match tail { |
| 2141 | Some(v) if ret != Nim::Unit => { |
| 2142 | let code = v.code.clone(); |
| 2143 | self.line(&format!("result = {code}")); |
| 2144 | } |
| 2145 | Some(v) => { |
| 2146 | // A trailing expression in a `()`-returning fn is evaluated for |
| 2147 | // its effect; Nim requires an explicit discard. |
| 2148 | let needs_discard = v.ty.as_ref().is_none_or(|t| *t != Nim::Unit); |
| 2149 | if needs_discard && !v.code.is_empty() { |
| 2150 | let code = v.code.clone(); |
| 2151 | self.line(&format!("discard {code}")); |
| 2152 | } |
| 2153 | } |
| 2154 | None => {} |
| 2155 | } |
| 2156 | if self.out.len() == before { |
| 2157 | self.line("discard"); |
| 2158 | } |
| 2159 | |
| 2160 | self.indent -= 1; |
| 2161 | self.ret = outer_ret; |
| Add generics; transpile the part of cosmic-theme that is reachable ff34e1b nandithebull 7h ago | 2162 | self.fn_generics = outer_fg; |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 2163 | self.pop_scope(); |
| 2164 | self.blank(); |
| 2165 | Ok(()) |
| 2166 | } |
| 2167 | |
| 2168 | // ---------------------------------------------------------- statements |
| 2169 | |
| 2170 | /// Lower a block's statements. Returns the block's trailing expression, |
| 2171 | /// if it has one, *without* emitting it — the caller decides whether that |
| 2172 | /// value is a return value, a binding, or discarded. |
| 2173 | fn block_body(&mut self, b: &syn::Block) -> Result<Option<Val>, String> { |
| 2174 | self.block_body_at(b, None) |
| 2175 | } |
| 2176 | |
| 2177 | fn block_body_at( |
| 2178 | &mut self, |
| 2179 | b: &syn::Block, |
| 2180 | expect: Option<&Nim>, |
| 2181 | ) -> Result<Option<Val>, String> { |
| 2182 | // An assignment target belongs to *this* block's trailing expression |
| 2183 | // only. A non-final `if` is a statement and must not assign anything. |
| 2184 | let target = self.target.take(); |
| 2185 | let n = b.stmts.len(); |
| 2186 | let mut tail = None; |
| 2187 | for (i, st) in b.stmts.iter().enumerate() { |
| 2188 | let last = i + 1 == n; |
| 2189 | match st { |
| 2190 | Stmt::Expr(e, None) if last && expressible(e) => { |
| 2191 | tail = Some(self.expr_at(e, expect)?) |
| 2192 | } |
| 2193 | Stmt::Expr(e, None) if last => { |
| 2194 | // A trailing `if`/`match` with statement arms, or a loop. |
| 2195 | // Lower it as statements; if this block's value is wanted, |
| 2196 | // each arm assigns it. |
| 2197 | match &target { |
| 2198 | Some((t, ty)) => { |
| 2199 | let (t, ty) = (t.clone(), ty.clone()); |
| 2200 | self.assign_from(e, &t, ty.as_ref())?; |
| 2201 | } |
| 2202 | None => self.stmt(st)?, |
| 2203 | } |
| 2204 | } |
| 2205 | _ => self.stmt(st)?, |
| 2206 | } |
| 2207 | } |
| 2208 | self.target = target; |
| 2209 | Ok(tail) |
| 2210 | } |
| 2211 | |
| 2212 | /// Lower a block in statement position (loop bodies, `if` arms). |
| 2213 | fn nested_block(&mut self, b: &syn::Block) -> Result<(), String> { |
| 2214 | self.push_scope(); |
| 2215 | self.indent += 1; |
| 2216 | let before = self.out.len(); |
| 2217 | let want = self.target.clone().and_then(|(_, t)| t); |
| 2218 | let tail = self.block_body_at(b, want.as_ref())?; |
| 2219 | self.emit_tail(tail); |
| 2220 | if self.out.len() == before { |
| 2221 | self.line("discard"); |
| 2222 | } |
| 2223 | self.indent -= 1; |
| 2224 | self.pop_scope(); |
| 2225 | Ok(()) |
| 2226 | } |
| 2227 | |
| 2228 | fn stmt(&mut self, s: &Stmt) -> Result<(), String> { |
| 2229 | match s { |
| 2230 | Stmt::Local(l) => self.local(l), |
| 2231 | Stmt::Expr(e, _) => { |
| 2232 | let v = self.expr_stmt(e)?; |
| 2233 | if let Some(v) = v { |
| 2234 | // A bare expression with a value must be discarded in Nim. |
| 2235 | let needs = v.ty.as_ref().is_none_or(|t| *t != Nim::Unit); |
| 2236 | let code = v.code.clone(); |
| 2237 | if needs { |
| 2238 | self.line(&format!("discard {code}")); |
| 2239 | } else if !code.is_empty() { |
| 2240 | self.line(&code); |
| 2241 | } |
| 2242 | } |
| 2243 | Ok(()) |
| 2244 | } |
| Transpile a second crate, adler2, to test whether any of this generalises 5fdd5be nandithebull 8h ago | 2245 | // A `const` declared inside a function body is local to it, and |
| 2246 | // must be emitted here rather than skipped as an already-emitted |
| 2247 | // top-level type. |
| 2248 | Stmt::Item(i) => self.item_inner(i), |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 2249 | Stmt::Macro(m) => { |
| 2250 | let line = self.macro_call(&m.mac)?; |
| 2251 | self.line(&line); |
| 2252 | Ok(()) |
| 2253 | } |
| 2254 | } |
| 2255 | } |
| 2256 | |
| 2257 | fn local(&mut self, l: &Local) -> Result<(), String> { |
| 2258 | let (name, mutable, ann): (String, bool, Option<Nim>) = match &l.pat { |
| 2259 | Pat::Ident(i) => (i.ident.to_string(), i.mutability.is_some(), None), |
| 2260 | Pat::Type(t) => match &*t.pat { |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 2261 | Pat::Ident(i) => (i.ident.to_string(), i.mutability.is_some(), Some(self.map_ty(&t.ty)?)), |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 2262 | _ => return Err("only `let <ident>` bindings are supported".into()), |
| 2263 | }, |
| 2264 | Pat::Wild(_) => ("_".into(), false, None), |
| Transpile a second crate, adler2, to test whether any of this generalises 5fdd5be nandithebull 8h ago | 2265 | Pat::Tuple(t) => return self.local_tuple(l, t), |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 2266 | _ => return Err("destructuring `let` is not implemented yet".into()), |
| 2267 | }; |
| 2268 | |
| 2269 | let Some(init) = &l.init else { |
| 2270 | // `let x: T;` — Nim's `var x: T` zero-initialises, which Rust does |
| 2271 | // not. Rust's own rules make reading it before assignment illegal, |
| 2272 | // so the two agree on every program rustc accepts. |
| 2273 | let t = ann.ok_or("`let` without an initialiser needs a type annotation")?; |
| 2274 | let t = t.owned(); |
| 2275 | self.line(&format!("var {}: {}", ident(&name), t.render())); |
| 2276 | self.bind(&name, t); |
| 2277 | return Ok(()); |
| 2278 | }; |
| 2279 | if init.diverge.is_some() { |
| 2280 | return Err("`let ... else` is not implemented yet".into()); |
| 2281 | } |
| 2282 | |
| 2283 | if !expressible(&init.expr) && name != "_" { |
| 2284 | // The initialiser is an `if`/`match` whose arms are statements. |
| 2285 | // Declare first, then let each arm assign into the binding. |
| 2286 | let t = ann |
| 2287 | .clone() |
| 2288 | .ok_or_else(|| { |
| 2289 | format!( |
| 2290 | "`let {name} = match/if ...` needs a type annotation: \ |
| 2291 | its arms are statements, so the binding must be \ |
| 2292 | declared before they run" |
| 2293 | ) |
| 2294 | })? |
| 2295 | .owned(); |
| 2296 | self.line(&format!("var {}: {}", ident(&name), t.render())); |
| 2297 | self.bind(&name, t.clone()); |
| 2298 | let target = ident(&name); |
| 2299 | return self.assign_from(&init.expr, &target, Some(&t)); |
| 2300 | } |
| 2301 | |
| Transpile a second crate, adler2, to test whether any of this generalises 5fdd5be nandithebull 8h ago | 2302 | // `let it = xs.chunks_exact(k)` binds an iterator, not a value. |
| 2303 | if is_iterator_expr(&init.expr) { |
| 2304 | let it = self.resolve_iter(&init.expr)?; |
| 2305 | self.bind_alias(&name, Alias::Iterator(Box::new(it))); |
| 2306 | return Ok(()); |
| 2307 | } |
| 2308 | |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 2309 | let v = self.expr_at(&init.expr, ann.as_ref())?; |
| Prove byte-identity for base16ct by enumerating whole input domains 99b8376 nandithebull 8h ago | 2310 | |
| 2311 | // `let s = &buf[..n]` binds a view of a place that is already in |
| 2312 | // scope. Nim's borrow checker will not let a `let` borrow out of a |
| 2313 | // local, and there is nothing to materialise anyway -- a view is a |
| 2314 | // reference. Binding it as an alias substitutes the same expression at |
| 2315 | // each use, which re-evaluates nothing because the initialiser is a |
| 2316 | // place expression with no side effects. |
| 2317 | if v.window.is_none() |
| 2318 | && matches!(v.ty, Some(Nim::OpenArray(_))) |
| 2319 | && is_pure_place(&init.expr) |
| 2320 | { |
| 2321 | let t = v.ty.clone().unwrap(); |
| 2322 | let elem = match &t { |
| 2323 | Nim::OpenArray(e) => Some((**e).clone()), |
| 2324 | _ => None, |
| 2325 | }; |
| 2326 | self.bind_alias(&name, Alias::Value { code: v.code.clone(), ty: Some(t) }); |
| 2327 | let _ = elem; |
| 2328 | return Ok(()); |
| 2329 | } |
| 2330 | |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 2331 | if let Some(w) = v.window.clone() { |
| 2332 | // `let dst = dst.get_mut(..n).ok_or(..)?;` -- the binding names a |
| 2333 | // view into the caller's buffer. Copying it into a `seq` would |
| 2334 | // still print the right bytes but would stop writes reaching the |
| 2335 | // caller, so it is bound as an alias. |
| 2336 | if v.guard.is_some() && v.guard_err.is_some() { |
| 2337 | return Err(format!( |
| 2338 | "`let {name} = ...get(..)` keeps an `Option` of a slice view, \ |
| 2339 | which Nim cannot represent; apply `?` or `unwrap()` to it \ |
| 2340 | in the same expression" |
| 2341 | )); |
| 2342 | } |
| 2343 | self.bind_alias(&name, w); |
| 2344 | return Ok(()); |
| 2345 | } |
| Add display.rs and the alloc half: all of base16ct now goes through afb2a6e nandithebull 9h ago | 2346 | // A `let` binding a borrow keeps the view: `let res = encode(..)?` |
| 2347 | // names the caller's buffer, and copying it into a `seq` would still |
| 2348 | // print the right bytes while silently breaking the aliasing. |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 2349 | let t = match (ann, &v.ty) { |
| Add display.rs and the alloc half: all of base16ct now goes through afb2a6e nandithebull 9h ago | 2350 | (Some(a), _) => a.unvar(), |
| 2351 | (None, Some(t)) => t.clone().unvar(), |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 2352 | (None, None) => { |
| 2353 | return Err(format!( |
| 2354 | "cannot infer the type of `let {name}`; annotate it — \ |
| 2355 | guessing here would change integer width, and with it the \ |
| 2356 | meaning of any arithmetic on `{name}`" |
| 2357 | )) |
| 2358 | } |
| 2359 | }; |
| 2360 | |
| 2361 | if name == "_" { |
| 2362 | let code = v.code.clone(); |
| 2363 | self.line(&format!("discard {code}")); |
| 2364 | return Ok(()); |
| 2365 | } |
| 2366 | // Rust's immutable `let` is Nim's `let`; `let mut` is `var`. Shadowing |
| 2367 | // works in both, so a re-`let` of the same name needs no rename. |
| Prove byte-identity for base16ct by enumerating whole input domains 99b8376 nandithebull 8h ago | 2368 | // |
| 2369 | // `let x = &mut y[..n]` is an immutable binding of a *mutable* borrow: |
| 2370 | // Rust may write through it, and Nim only accepts a `var` where a |
| 2371 | // `var` parameter is wanted, so the binding has to be one. |
| 2372 | let mutable = mutable || is_mut_borrow(&init.expr); |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 2373 | let kw = if mutable { "var" } else { "let" }; |
| Add generics; transpile the part of cosmic-theme that is reachable ff34e1b nandithebull 7h ago | 2374 | // Inside a generic proc the binding's type may mention a parameter Nim |
| 2375 | // will infer; naming it in an annotation would not resolve. |
| 2376 | let line = if self.mentions_type_param(&t) { |
| 2377 | format!("{} {} = {}", kw, ident(&name), v.code) |
| 2378 | } else { |
| 2379 | format!("{} {}: {} = {}", kw, ident(&name), t.render(), v.code) |
| 2380 | }; |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 2381 | self.line(&line); |
| 2382 | self.bind(&name, t); |
| 2383 | Ok(()) |
| 2384 | } |
| 2385 | |
| Transpile a second crate, adler2, to test whether any of this generalises 5fdd5be nandithebull 8h ago | 2386 | /// `let (a, b) = ..` — tuple destructuring. |
| 2387 | fn local_tuple(&mut self, l: &Local, t: &syn::PatTuple) -> Result<(), String> { |
| 2388 | let Some(init) = &l.init else { |
| 2389 | return Err("a destructuring `let` needs an initialiser".into()); |
| 2390 | }; |
| 2391 | let names: Vec<(String, bool)> = t |
| 2392 | .elems |
| 2393 | .iter() |
| 2394 | .map(|p| match p { |
| 2395 | Pat::Ident(i) => Ok((i.ident.to_string(), i.mutability.is_some())), |
| 2396 | Pat::Wild(_) => Ok(("_".to_string(), false)), |
| 2397 | _ => Err("only plain identifiers are supported in a destructuring `let`"), |
| 2398 | }) |
| 2399 | .collect::<Result<_, _>>()?; |
| 2400 | |
| 2401 | // `split_at` hands back two *views* of the same slice. Nim has no |
| 2402 | // tuple of views, and there is nothing to materialise anyway, so each |
| 2403 | // name becomes a window into the original. |
| 2404 | if let Expr::MethodCall(m) = &*init.expr { |
| 2405 | let mname = m.method.to_string(); |
| 2406 | if (mname == "split_at" || mname == "split_at_mut") |
| 2407 | && m.args.len() == 1 |
| 2408 | && names.len() == 2 |
| 2409 | { |
| 2410 | let (code, base, len, elem) = self.slice_parts(&m.receiver)?; |
| 2411 | let at = self.expr(&m.args[0])?; |
| 2412 | let cut = self.fresh("Cut"); |
| 2413 | self.line(&format!("let {}: int = int({})", cut, at.code)); |
| 2414 | self.bind_alias( |
| 2415 | &names[0].0, |
| 2416 | Alias::Window { |
| 2417 | code: code.clone(), |
| 2418 | off: base.clone(), |
| 2419 | len: cut.clone(), |
| 2420 | elem: elem.clone(), |
| 2421 | }, |
| 2422 | ); |
| 2423 | self.bind_alias( |
| 2424 | &names[1].0, |
| 2425 | Alias::Window { |
| 2426 | code, |
| 2427 | off: format!("({} + {})", base, cut), |
| 2428 | len: format!("({} - {})", len, cut), |
| 2429 | elem, |
| 2430 | }, |
| 2431 | ); |
| 2432 | return Ok(()); |
| 2433 | } |
| 2434 | } |
| 2435 | |
| 2436 | let v = self.expr(&init.expr)?; |
| 2437 | let tys = match &v.ty { |
| 2438 | Some(Nim::Tuple(ts)) if ts.len() == names.len() => ts.clone(), |
| 2439 | _ => { |
| 2440 | return Err(format!( |
| 2441 | "cannot destructure this into {} bindings: its type is not a \ |
| 2442 | tuple of that many elements", |
| 2443 | names.len() |
| 2444 | )) |
| 2445 | } |
| 2446 | }; |
| 2447 | let kw = if names.iter().any(|(_, m)| *m) { "var" } else { "let" }; |
| 2448 | let lhs: Vec<String> = names.iter().map(|(n, _)| ident(n)).collect(); |
| 2449 | self.line(&format!("{} ({}) = {}", kw, lhs.join(", "), v.code)); |
| 2450 | for ((n, _), t) in names.iter().zip(tys) { |
| 2451 | self.bind(n, t); |
| 2452 | } |
| 2453 | Ok(()) |
| 2454 | } |
| 2455 | |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 2456 | /// Expressions that are statements in Rust and statements in Nim too |
| 2457 | /// (control flow). Returns `None` when it emitted lines itself. |
| 2458 | fn expr_stmt(&mut self, e: &Expr) -> Result<Option<Val>, String> { |
| 2459 | match e { |
| 2460 | Expr::If(_) => { |
| 2461 | self.if_stmt(e)?; |
| 2462 | Ok(None) |
| 2463 | } |
| 2464 | Expr::While(w) => { |
| 2465 | if w.label.is_some() { |
| 2466 | return Err("loop labels are not implemented yet".into()); |
| 2467 | } |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 2468 | self.in_loop_cond = true; |
| 2469 | let c = self.expr(&w.cond); |
| 2470 | self.in_loop_cond = false; |
| 2471 | let c = c?; |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 2472 | self.line(&format!("while {}:", c.code)); |
| 2473 | let saved = self.target.take(); |
| 2474 | self.nested_block(&w.body)?; |
| 2475 | self.target = saved; |
| 2476 | Ok(None) |
| 2477 | } |
| 2478 | Expr::Loop(l) => { |
| 2479 | if l.label.is_some() { |
| 2480 | return Err("loop labels are not implemented yet".into()); |
| 2481 | } |
| 2482 | self.line("while true:"); |
| 2483 | let saved = self.target.take(); |
| 2484 | self.nested_block(&l.body)?; |
| 2485 | self.target = saved; |
| 2486 | Ok(None) |
| 2487 | } |
| 2488 | Expr::ForLoop(f) => { |
| 2489 | self.for_loop(f)?; |
| 2490 | Ok(None) |
| 2491 | } |
| 2492 | Expr::Block(b) => { |
| 2493 | if b.label.is_some() { |
| 2494 | return Err("block labels are not implemented yet".into()); |
| 2495 | } |
| 2496 | self.line("block:"); |
| 2497 | self.nested_block(&b.block)?; |
| 2498 | Ok(None) |
| 2499 | } |
| Add closures and unsafe; base16ct's lower.rs and upper.rs go through 0a375d8 nandithebull 9h ago | 2500 | Expr::Unsafe(u) => { |
| 2501 | // Transparent in statement position too, for the same reason. |
| 2502 | self.nested_block_flat(&u.block)?; |
| 2503 | Ok(None) |
| 2504 | } |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 2505 | Expr::Match(_) => { |
| 2506 | self.match_stmt(e)?; |
| 2507 | Ok(None) |
| 2508 | } |
| 2509 | Expr::Return(r) => { |
| 2510 | match &r.expr { |
| 2511 | Some(e) => { |
| 2512 | let want = self.ret.clone(); |
| 2513 | let v = self.expr_at(e, want.as_ref())?; |
| 2514 | self.line(&format!("return {}", v.code)); |
| 2515 | } |
| 2516 | None => self.line("return"), |
| 2517 | } |
| 2518 | Ok(None) |
| 2519 | } |
| 2520 | Expr::Break(b) => { |
| 2521 | if b.expr.is_some() || b.label.is_some() { |
| 2522 | return Err("`break` with a value or a label is not implemented yet".into()); |
| 2523 | } |
| 2524 | self.line("break"); |
| 2525 | Ok(None) |
| 2526 | } |
| 2527 | Expr::Continue(c) => { |
| 2528 | if c.label.is_some() { |
| 2529 | return Err("labelled `continue` is not implemented yet".into()); |
| 2530 | } |
| 2531 | self.line("continue"); |
| 2532 | Ok(None) |
| 2533 | } |
| 2534 | Expr::Assign(a) => { |
| 2535 | let lhs = self.expr(&a.left)?; |
| 2536 | if !expressible(&a.right) { |
| 2537 | let target = lhs.code.clone(); |
| 2538 | return self.assign_from(&a.right, &target, lhs.ty.as_ref()).map(|_| None); |
| 2539 | } |
| 2540 | let rhs = self.expr_at(&a.right, lhs.ty.as_ref())?; |
| 2541 | self.line(&format!("{} = {}", lhs.code, rhs.code)); |
| 2542 | Ok(None) |
| 2543 | } |
| 2544 | Expr::Binary(b) if is_compound(&b.op) => { |
| 2545 | let lhs = self.expr(&b.left)?; |
| Transpile a second crate, adler2, to test whether any of this generalises 5fdd5be nandithebull 8h ago | 2546 | // A compound assignment on a user type goes to that type's own |
| 2547 | // `impl OpAssign`, not to Nim's built-in operator. |
| 2548 | if let Some(f) = self.op_proc(&lhs.ty, compound_symbol(&b.op)) { |
| 2549 | // The impl's own parameter type types the right operand, |
| 2550 | // so `b_vec *= 4` takes 4 at the width the impl declares. |
| 2551 | let want = self.op_param(&lhs.ty, compound_symbol(&b.op)); |
| 2552 | let rhs = self.expr_at(&b.right, want.as_ref())?; |
| 2553 | self.line(&format!("{}({}, {})", f, lhs.code, rhs.code)); |
| 2554 | return Ok(None); |
| 2555 | } |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 2556 | // `i += 1` must widen the literal to `i`'s type, not to the |
| 2557 | // i32 an unconstrained Rust literal would default to. |
| 2558 | let rhs = self.expr_at(&b.right, lhs.ty.as_ref())?; |
| 2559 | let op = self.bin_op(&b.op, &lhs, &rhs)?; |
| 2560 | // Nim has no `shl=` etc., and `+=` on a `let` is illegal in |
| 2561 | // both languages, so the expanded form is always correct. |
| 2562 | self.line(&format!("{} = {} {} {}", lhs.code, lhs.code, op, rhs.code)); |
| 2563 | Ok(None) |
| 2564 | } |
| 2565 | Expr::Macro(m) => { |
| 2566 | let line = self.macro_call(&m.mac)?; |
| 2567 | self.line(&line); |
| 2568 | Ok(None) |
| 2569 | } |
| 2570 | _ => Ok(Some(self.expr(e)?)), |
| 2571 | } |
| 2572 | } |
| 2573 | |
| 2574 | /// Lower `e` in statement position, assigning each arm's value to |
| 2575 | /// `target`. This is how Rust's expression-oriented `if`/`match` survive |
| 2576 | /// the trip when their arms are too big for a Nim `if`-expression. |
| 2577 | fn assign_from( |
| 2578 | &mut self, |
| 2579 | e: &Expr, |
| 2580 | target: &str, |
| 2581 | expect: Option<&Nim>, |
| 2582 | ) -> Result<(), String> { |
| 2583 | let saved = self.target.replace((target.to_string(), expect.cloned())); |
| 2584 | let r = match e { |
| 2585 | Expr::If(_) => self.if_stmt(e), |
| 2586 | Expr::Match(_) => self.match_stmt(e), |
| 2587 | other => { |
| 2588 | let v = self.expr_at(other, expect)?; |
| 2589 | self.line(&format!("{} = {}", target, v.code)); |
| 2590 | Ok(()) |
| 2591 | } |
| 2592 | }; |
| 2593 | self.target = saved; |
| 2594 | r |
| 2595 | } |
| 2596 | |
| 2597 | /// Emit a block's value into the active assignment target, if there is |
| 2598 | /// one, or discard it if there is not. |
| 2599 | fn emit_tail(&mut self, v: Option<Val>) { |
| 2600 | let Some(v) = v else { return }; |
| 2601 | match self.target.clone() { |
| 2602 | Some((t, _)) => { |
| 2603 | let code = v.code.clone(); |
| 2604 | self.line(&format!("{t} = {code}")); |
| 2605 | } |
| 2606 | None => { |
| 2607 | let needs = v.ty.as_ref().is_none_or(|t| *t != Nim::Unit); |
| 2608 | let code = v.code.clone(); |
| 2609 | if needs { |
| 2610 | self.line(&format!("discard {code}")); |
| 2611 | } else if !code.is_empty() { |
| 2612 | self.line(&code); |
| 2613 | } |
| 2614 | } |
| 2615 | } |
| 2616 | } |
| 2617 | |
| 2618 | fn if_stmt(&mut self, e: &Expr) -> Result<(), String> { |
| 2619 | let Expr::If(i) = e else { unreachable!() }; |
| 2620 | if let Expr::Let(_) = &*i.cond { |
| 2621 | return Err("`if let` is not implemented yet".into()); |
| 2622 | } |
| 2623 | let c = self.expr(&i.cond)?; |
| 2624 | self.line(&format!("if {}:", c.code)); |
| 2625 | self.nested_block(&i.then_branch)?; |
| 2626 | match &i.else_branch { |
| 2627 | None => {} |
| 2628 | Some((_, els)) => match &**els { |
| 2629 | Expr::If(_) => { |
| 2630 | // Nim needs `elif`; splice the nested `if` in as one. |
| 2631 | let mark = self.out.len(); |
| 2632 | self.if_stmt(els)?; |
| 2633 | let tail = self.out.split_off(mark); |
| 2634 | let indent = " ".repeat(self.indent); |
| 2635 | self.out.push_str(&tail.replacen(&format!("{indent}if "), &format!("{indent}elif "), 1)); |
| 2636 | } |
| 2637 | Expr::Block(b) => { |
| 2638 | self.line("else:"); |
| 2639 | self.nested_block(&b.block)?; |
| 2640 | } |
| 2641 | _ => return Err("unsupported `else` form".into()), |
| 2642 | }, |
| 2643 | } |
| 2644 | Ok(()) |
| 2645 | } |
| 2646 | |
| 2647 | fn for_loop(&mut self, f: &syn::ExprForLoop) -> Result<(), String> { |
| 2648 | if f.label.is_some() { |
| 2649 | return Err("loop labels are not implemented yet".into()); |
| 2650 | } |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 2651 | let it = self.resolve_iter(&f.expr)?; |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 2652 | |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 2653 | // One index loop drives the whole chain. Rust's adaptors are lazy and |
| 2654 | // compose; resolving them to an index and binding each name to an |
| 2655 | // lvalue reproduces that without materialising anything. |
| 2656 | let i = self.fresh("Idx"); |
| 2657 | self.line(&format!("for {} in 0 ..< int({}):", i, it.len())); |
| 2658 | self.indent += 1; |
| 2659 | self.push_scope(); |
| 2660 | let before = self.out.len(); |
| 2661 | |
| 2662 | self.bind_pattern(&f.pat, &it, &i)?; |
| 2663 | |
| 2664 | let saved = self.target.take(); |
| 2665 | if let Some(v) = self.block_body(&f.body)? { |
| 2666 | let code = v.code.clone(); |
| 2667 | self.line(&format!("discard {code}")); |
| 2668 | } |
| 2669 | self.target = saved; |
| 2670 | if self.out.len() == before { |
| 2671 | self.line("discard"); |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 2672 | } |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 2673 | self.pop_scope(); |
| 2674 | self.indent -= 1; |
| 2675 | Ok(()) |
| 2676 | } |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 2677 | |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 2678 | /// Resolve a chain of iterator adaptors into a single `Iter`. |
| 2679 | /// |
| 2680 | /// Only adaptors with an exact index-loop equivalent are accepted. `map`, |
| 2681 | /// `filter`, `take_while` and friends are rejected rather than partially |
| 2682 | /// honoured: silently dropping an adaptor would change which elements the |
| 2683 | /// loop visits. |
| 2684 | fn resolve_iter(&mut self, e: &Expr) -> Result<Iter, String> { |
| 2685 | match e { |
| 2686 | Expr::Reference(r) => self.resolve_iter(&r.expr), |
| 2687 | Expr::Paren(p) => self.resolve_iter(&p.expr), |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 2688 | Expr::Range(r) => { |
| 2689 | let lo = match &r.start { |
| 2690 | Some(e) => self.expr(e)?, |
| 2691 | None => return Err("a `for` over `..n` needs a start bound".into()), |
| 2692 | }; |
| 2693 | let hi = match &r.end { |
| 2694 | Some(e) => self.expr(e)?, |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 2695 | None => { |
| 2696 | return Err("a `for` over an unbounded range would not terminate".into()) |
| 2697 | } |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 2698 | }; |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 2699 | let ty = lo.ty.clone().or(hi.ty.clone()); |
| 2700 | Ok(Iter::Range { |
| 2701 | lo: lo.code, |
| 2702 | hi: hi.code, |
| 2703 | closed: matches!(r.limits, syn::RangeLimits::Closed(_)), |
| 2704 | ty, |
| 2705 | }) |
| 2706 | } |
| 2707 | Expr::MethodCall(m) => { |
| 2708 | let name = m.method.to_string(); |
| 2709 | match name.as_str() { |
| 2710 | "iter" | "into_iter" | "iter_mut" if m.args.is_empty() => { |
| 2711 | let mut it = self.resolve_iter(&m.receiver)?; |
| 2712 | if name == "iter_mut" { |
| 2713 | if let Iter::Elems { mutable, .. } = &mut it { |
| 2714 | *mutable = true; |
| 2715 | } |
| 2716 | } |
| 2717 | Ok(it) |
| 2718 | } |
| 2719 | "enumerate" if m.args.is_empty() => { |
| 2720 | Ok(Iter::Enumerate(Box::new(self.resolve_iter(&m.receiver)?))) |
| 2721 | } |
| 2722 | "zip" if m.args.len() == 1 => { |
| 2723 | let a = self.resolve_iter(&m.receiver)?; |
| 2724 | let b = self.resolve_iter(&m.args[0])?; |
| 2725 | Ok(Iter::Zip(Box::new(a), Box::new(b))) |
| 2726 | } |
| 2727 | "chunks_exact" | "chunks_exact_mut" if m.args.len() == 1 => { |
| Add closures and unsafe; base16ct's lower.rs and upper.rs go through 0a375d8 nandithebull 9h ago | 2728 | let (code, base, len, elem) = self.slice_parts(&m.receiver)?; |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 2729 | let k = self.expr(&m.args[0])?; |
| 2730 | Ok(Iter::Chunks { |
| Add closures and unsafe; base16ct's lower.rs and upper.rs go through 0a375d8 nandithebull 9h ago | 2731 | code, |
| 2732 | base, |
| 2733 | len, |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 2734 | k: k.code, |
| Add closures and unsafe; base16ct's lower.rs and upper.rs go through 0a375d8 nandithebull 9h ago | 2735 | elem, |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 2736 | mutable: name.ends_with("_mut"), |
| 2737 | }) |
| 2738 | } |
| 2739 | "windows" if m.args.len() == 1 => { |
| Add closures and unsafe; base16ct's lower.rs and upper.rs go through 0a375d8 nandithebull 9h ago | 2740 | let (code, base, len, elem) = self.slice_parts(&m.receiver)?; |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 2741 | let k = self.expr(&m.args[0])?; |
| Add closures and unsafe; base16ct's lower.rs and upper.rs go through 0a375d8 nandithebull 9h ago | 2742 | Ok(Iter::Windows { code, base, len, k: k.code, elem }) |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 2743 | } |
| 2744 | other => Err(format!( |
| 2745 | "iterator adaptor `.{other}()` is not implemented; it has \ |
| 2746 | no index-loop equivalent here, and dropping it would \ |
| 2747 | change which elements the loop visits" |
| 2748 | )), |
| 2749 | } |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 2750 | } |
| Transpile a second crate, adler2, to test whether any of this generalises 5fdd5be nandithebull 8h ago | 2751 | Expr::Path(p) => { |
| 2752 | let n = path_name(&p.path); |
| 2753 | if let Some(Alias::Iterator(it)) = self.lookup_alias(&n) { |
| 2754 | return Ok((*it).clone()); |
| 2755 | } |
| 2756 | if let Some(Alias::Window { code, off, len, elem }) = self.lookup_alias(&n) { |
| 2757 | return Ok(Iter::Elems { code, off, len, elem, mutable: false }); |
| 2758 | } |
| 2759 | let v = self.expr(e)?; |
| 2760 | Ok(Iter::Elems { |
| 2761 | len: format!("{}.len", v.code), |
| 2762 | elem: elem_of(&v.ty), |
| 2763 | code: v.code, |
| 2764 | off: "0".into(), |
| 2765 | mutable: false, |
| 2766 | }) |
| 2767 | } |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 2768 | other => { |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 2769 | // A `for` binding that is itself a window iterates that window, |
| 2770 | // not the whole container it points into. |
| 2771 | if let Some(Alias::Window { code, off, len, elem }) = self.window_of(other) { |
| Add closures and unsafe; base16ct's lower.rs and upper.rs go through 0a375d8 nandithebull 9h ago | 2772 | return Ok(Iter::Elems { code, off, len, elem, mutable: false }); |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 2773 | } |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 2774 | let v = self.expr(other)?; |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 2775 | Ok(Iter::Elems { |
| 2776 | len: format!("{}.len", v.code), |
| 2777 | elem: elem_of(&v.ty), |
| 2778 | code: v.code, |
| 2779 | off: "0".into(), |
| 2780 | mutable: false, |
| 2781 | }) |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 2782 | } |
| 2783 | } |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 2784 | } |
| 2785 | |
| 2786 | /// Bind a `for` pattern against a resolved iterator at index `i`. |
| 2787 | fn bind_pattern(&mut self, p: &Pat, it: &Iter, i: &str) -> Result<(), String> { |
| 2788 | match (p, it) { |
| 2789 | (Pat::Tuple(t), Iter::Zip(a, b)) if t.elems.len() == 2 => { |
| 2790 | self.bind_pattern(&t.elems[0], a, i)?; |
| 2791 | self.bind_pattern(&t.elems[1], b, i) |
| 2792 | } |
| 2793 | (Pat::Tuple(t), Iter::Enumerate(inner)) if t.elems.len() == 2 => { |
| 2794 | if let Pat::Ident(id) = &t.elems[0] { |
| 2795 | let n = id.ident.to_string(); |
| 2796 | // Rust's `enumerate` counts in `usize`. |
| 2797 | self.line(&format!("let {}: uint = uint({})", ident(&n), i)); |
| 2798 | self.bind(&n, Nim::Prim("uint".into())); |
| 2799 | } |
| 2800 | self.bind_pattern(&t.elems[1], inner, i) |
| 2801 | } |
| 2802 | (_, Iter::Zip(..) | Iter::Enumerate(..)) => Err( |
| 2803 | "a `zip`/`enumerate` loop needs a two-element tuple pattern".into(), |
| 2804 | ), |
| 2805 | (Pat::Wild(_), _) => Ok(()), |
| Add closures and unsafe; base16ct's lower.rs and upper.rs go through 0a375d8 nandithebull 9h ago | 2806 | // `for &byte in xs` — the `&` destructures the reference, which in |
| 2807 | // Nim is already the value. |
| 2808 | (Pat::Reference(r), _) => self.bind_pattern(&r.pat, it, i), |
| 2809 | (Pat::Paren(p), _) => self.bind_pattern(&p.pat, it, i), |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 2810 | (Pat::Ident(id), _) => { |
| 2811 | let name = id.ident.to_string(); |
| 2812 | match it { |
| 2813 | Iter::Range { lo, ty, .. } => { |
| 2814 | let t = ty.clone().unwrap_or(Nim::Prim("int".into())); |
| 2815 | // The loop counts from zero; the range's own start is |
| 2816 | // added back so the binding has Rust's value and type. |
| 2817 | self.line(&format!( |
| 2818 | "let {}: {} = {}({}) + {}", |
| 2819 | ident(&name), |
| 2820 | t.render(), |
| 2821 | t.render(), |
| 2822 | i, |
| 2823 | lo |
| 2824 | )); |
| 2825 | self.bind(&name, t); |
| 2826 | Ok(()) |
| 2827 | } |
| 2828 | Iter::Elems { code, off, elem, mutable, .. } => { |
| 2829 | let access = if off == "0" { |
| 2830 | format!("{}[{}]", code, i) |
| 2831 | } else { |
| 2832 | format!("{}[{} + {}]", code, off, i) |
| 2833 | }; |
| 2834 | if *mutable { |
| 2835 | // An alias, not a copy: assigning through the |
| 2836 | // binding must reach the original element. |
| 2837 | self.bind_alias( |
| 2838 | &name, |
| 2839 | Alias::Value { code: access, ty: elem.clone() }, |
| 2840 | ); |
| 2841 | } else { |
| 2842 | let t = elem |
| 2843 | .clone() |
| 2844 | .ok_or("cannot infer the element type of this `for`")?; |
| 2845 | self.line(&format!( |
| 2846 | "let {}: {} = {}", |
| 2847 | ident(&name), |
| 2848 | t.render(), |
| 2849 | access |
| 2850 | )); |
| 2851 | self.bind(&name, t); |
| 2852 | } |
| 2853 | Ok(()) |
| 2854 | } |
| Add closures and unsafe; base16ct's lower.rs and upper.rs go through 0a375d8 nandithebull 9h ago | 2855 | Iter::Chunks { code, base, k, elem, .. } => { |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 2856 | self.bind_alias( |
| 2857 | &name, |
| 2858 | Alias::Window { |
| 2859 | code: code.clone(), |
| Add closures and unsafe; base16ct's lower.rs and upper.rs go through 0a375d8 nandithebull 9h ago | 2860 | off: format!("({} + {} * int({}))", base, i, k), |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 2861 | len: format!("int({})", k), |
| 2862 | elem: elem.clone(), |
| 2863 | }, |
| 2864 | ); |
| 2865 | Ok(()) |
| 2866 | } |
| Add closures and unsafe; base16ct's lower.rs and upper.rs go through 0a375d8 nandithebull 9h ago | 2867 | Iter::Windows { code, base, k, elem, .. } => { |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 2868 | self.bind_alias( |
| 2869 | &name, |
| 2870 | Alias::Window { |
| 2871 | code: code.clone(), |
| Add closures and unsafe; base16ct's lower.rs and upper.rs go through 0a375d8 nandithebull 9h ago | 2872 | off: format!("({} + {})", base, i), |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 2873 | len: format!("int({})", k), |
| 2874 | elem: elem.clone(), |
| 2875 | }, |
| 2876 | ); |
| 2877 | Ok(()) |
| 2878 | } |
| 2879 | // Handled above: a zip or enumerate needs a tuple pattern, |
| 2880 | // and binding one name to the pair is not supported. |
| 2881 | Iter::Zip(..) | Iter::Enumerate(..) => unreachable!(), |
| 2882 | } |
| 2883 | } |
| 2884 | _ => Err("unsupported `for` pattern".into()), |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 2885 | } |
| 2886 | } |
| 2887 | |
| 2888 | fn match_stmt(&mut self, e: &Expr) -> Result<(), String> { |
| 2889 | let Expr::Match(m) = e else { unreachable!() }; |
| 2890 | let scrut = self.expr(&m.expr)?; |
| 2891 | let t = scrut |
| 2892 | .ty |
| 2893 | .clone() |
| 2894 | .ok_or("cannot infer the type of a `match` scrutinee")?; |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 2895 | let name = self.fresh("Match"); |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 2896 | self.line(&format!("let {}: {} = {}", name, t.render(), scrut.code)); |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 2897 | |
| 2898 | // A `match` whose arms neither bind nor guard is a Nim `case`, which |
| 2899 | // is exhaustiveness-checked the way Rust's is. Anything richer becomes |
| 2900 | // an if/elif chain, because Nim's `case` cannot destructure. |
| 2901 | let plain = m.arms.iter().all(|a| { |
| 2902 | !matches!(a.pat, Pat::Guard(_)) && !binds(&a.pat) && !destructures(&a.pat) |
| 2903 | }); |
| 2904 | if plain { |
| 2905 | self.match_case(m, &name, &t) |
| 2906 | } else { |
| 2907 | self.match_chain(m, &name, &t) |
| 2908 | } |
| 2909 | } |
| 2910 | |
| 2911 | fn match_case( |
| 2912 | &mut self, |
| 2913 | m: &syn::ExprMatch, |
| 2914 | name: &str, |
| 2915 | t: &Nim, |
| 2916 | ) -> Result<(), String> { |
| 2917 | // A variant object is discriminated by its `kind` field. |
| 2918 | let on_kind = matches!(t, Nim::Named(n, _) if self.enums.get(n).is_some_and(|d| !d.simple)); |
| 2919 | self.line(&format!("case {}{}", name, if on_kind { ".kind" } else { "" })); |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 2920 | |
| 2921 | let mut saw_wild = false; |
| 2922 | for arm in &m.arms { |
| 2923 | match &arm.pat { |
| 2924 | Pat::Wild(_) => { |
| 2925 | saw_wild = true; |
| 2926 | self.line("else:"); |
| 2927 | } |
| 2928 | p => { |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 2929 | let labels = self.pat_labels(p, Some(t))?; |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 2930 | self.line(&format!("of {}:", labels.join(", "))); |
| 2931 | } |
| 2932 | } |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 2933 | self.arm_body(&arm.body)?; |
| 2934 | } |
| 2935 | if !saw_wild && !self.case_is_total(t, m) { |
| 2936 | // Rust checked exhaustiveness already, but Nim cannot always see |
| 2937 | // it -- an integer `case` needs every value covered -- so make the |
| 2938 | // unreachable arm explicit rather than leave a compile error. |
| 2939 | self.line("else:"); |
| 2940 | self.line(" rsPanic(\"unreachable match arm\")"); |
| 2941 | } |
| 2942 | Ok(()) |
| 2943 | } |
| 2944 | |
| 2945 | /// Whether a Nim `case` over this type is already total, in which case |
| 2946 | /// adding an `else` would be a compile error rather than a safety net. |
| 2947 | fn case_is_total(&self, t: &Nim, m: &syn::ExprMatch) -> bool { |
| 2948 | let Nim::Named(n, _) = t else { return false }; |
| 2949 | let Some(def) = self.enums.get(n) else { return false }; |
| 2950 | def.variants.len() == m.arms.len() |
| 2951 | } |
| 2952 | |
| 2953 | /// The if/elif form, for arms that bind or destructure. |
| 2954 | fn match_chain( |
| 2955 | &mut self, |
| 2956 | m: &syn::ExprMatch, |
| 2957 | name: &str, |
| 2958 | t: &Nim, |
| 2959 | ) -> Result<(), String> { |
| 2960 | let mut first = true; |
| 2961 | let mut closed = false; |
| 2962 | for arm in &m.arms { |
| 2963 | let (pat, guard) = match &arm.pat { |
| 2964 | Pat::Guard(g) => (&*g.pat, Some(&*g.guard)), |
| 2965 | p => (p, None), |
| 2966 | }; |
| 2967 | if guard.is_some() && binds(pat) { |
| 2968 | return Err("a `match` guard on a binding pattern is not \ |
| 2969 | implemented yet" |
| 2970 | .into()); |
| 2971 | } |
| 2972 | let test = self.pat_test(pat, name, t)?; |
| 2973 | let test = match (test, guard) { |
| 2974 | (Some(t), Some(g)) => { |
| 2975 | let g = self.expr(g)?; |
| 2976 | Some(format!("({}) and ({})", t, g.code)) |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 2977 | } |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 2978 | (None, Some(g)) => Some(self.expr(g)?.code), |
| 2979 | (t, None) => t, |
| 2980 | }; |
| 2981 | match test { |
| 2982 | Some(test) => { |
| 2983 | self.line(&format!( |
| 2984 | "{} {}:", |
| 2985 | if first { "if" } else { "elif" }, |
| 2986 | test |
| 2987 | )); |
| 2988 | first = false; |
| 2989 | } |
| 2990 | None => { |
| 2991 | // An irrefutable pattern: everything left falls here. |
| 2992 | if first { |
| 2993 | self.line("block:"); |
| 2994 | } else { |
| 2995 | self.line("else:"); |
| 2996 | } |
| 2997 | closed = true; |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 2998 | } |
| 2999 | } |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 3000 | self.indent += 1; |
| 3001 | self.push_scope(); |
| 3002 | let before = self.out.len(); |
| 3003 | self.pat_bind(pat, name, t)?; |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 3004 | self.indent -= 1; |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 3005 | self.arm_body_at(&arm.body, before)?; |
| 3006 | self.pop_scope(); |
| 3007 | if closed { |
| 3008 | break; |
| 3009 | } |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 3010 | } |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 3011 | if !closed { |
| 3012 | // Rust proved this unreachable; Nim cannot see that, and leaving |
| 3013 | // the chain open would silently fall through instead. |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 3014 | self.line("else:"); |
| 3015 | self.line(" rsPanic(\"unreachable match arm\")"); |
| 3016 | } |
| 3017 | Ok(()) |
| 3018 | } |
| 3019 | |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 3020 | /// The condition that selects this arm, or `None` if it always matches. |
| 3021 | fn pat_test(&mut self, p: &Pat, name: &str, t: &Nim) -> Result<Option<String>, String> { |
| 3022 | Ok(match p { |
| 3023 | Pat::Wild(_) => None, |
| 3024 | Pat::Ident(i) if i.subpat.is_none() => None, |
| 3025 | Pat::Or(o) => { |
| 3026 | let mut parts = Vec::new(); |
| 3027 | for c in &o.cases { |
| 3028 | match self.pat_test(c, name, t)? { |
| 3029 | Some(x) => parts.push(x), |
| 3030 | None => return Ok(None), |
| 3031 | } |
| 3032 | } |
| 3033 | Some(format!("({})", parts.join(" or "))) |
| 3034 | } |
| 3035 | Pat::Lit(_) | Pat::Range(_) => { |
| 3036 | let labels = self.pat_labels(p, Some(t))?; |
| 3037 | Some(match p { |
| 3038 | Pat::Range(_) => format!("({} in {})", name, labels[0]), |
| 3039 | _ => format!("({} == {})", name, labels[0]), |
| 3040 | }) |
| 3041 | } |
| 3042 | Pat::Path(pp) => Some(self.variant_test(&pp.path, name, t)?), |
| 3043 | Pat::TupleStruct(ts) => Some(self.variant_test(&ts.path, name, t)?), |
| 3044 | Pat::Struct(st) => Some(self.variant_test(&st.path, name, t)?), |
| 3045 | Pat::Paren(pp) => return self.pat_test(&pp.pat, name, t), |
| 3046 | Pat::Reference(r) => return self.pat_test(&r.pat, name, t), |
| 3047 | _ => return Err("unsupported `match` pattern".into()), |
| 3048 | }) |
| 3049 | } |
| 3050 | |
| 3051 | /// The discriminant test for `Ok`/`Err`/`Some`/`None` or an enum variant. |
| 3052 | fn variant_test(&self, path: &syn::Path, name: &str, t: &Nim) -> Result<String, String> { |
| 3053 | let last = path_name(path); |
| 3054 | match last.as_str() { |
| 3055 | "Ok" => return Ok(format!("{name}.ok")), |
| 3056 | "Err" => return Ok(format!("(not {name}.ok)")), |
| 3057 | "Some" => return Ok(format!("{name}.has")), |
| 3058 | "None" => return Ok(format!("(not {name}.has)")), |
| 3059 | _ => {} |
| 3060 | } |
| 3061 | let Some((def, v)) = self.resolve_variant(path) else { |
| 3062 | return Err(format!( |
| 3063 | "`{last}` in a pattern is not a known enum variant; if it names \ |
| 3064 | an enum declared in another module, that is not implemented yet" |
| 3065 | )); |
| 3066 | }; |
| 3067 | if let Nim::Named(n, _) = t { |
| 3068 | if *n != def.name { |
| 3069 | return Err(format!( |
| 3070 | "pattern `{}::{}` does not match the scrutinee type `{}`", |
| 3071 | def.name, v, n |
| 3072 | )); |
| 3073 | } |
| 3074 | } |
| 3075 | Ok(if def.simple { |
| 3076 | format!("({} == {}.{})", name, ident(&def.name), ident(&v)) |
| 3077 | } else { |
| 3078 | format!("({}.kind == {})", name, def.kind_ident(&v)) |
| 3079 | }) |
| 3080 | } |
| 3081 | |
| 3082 | /// Emit the `let`s that a pattern's bindings introduce. |
| 3083 | fn pat_bind(&mut self, p: &Pat, name: &str, t: &Nim) -> Result<(), String> { |
| 3084 | match p { |
| 3085 | Pat::Wild(_) | Pat::Lit(_) | Pat::Range(_) | Pat::Path(_) | Pat::Or(_) => Ok(()), |
| 3086 | Pat::Paren(pp) => self.pat_bind(&pp.pat, name, t), |
| 3087 | Pat::Reference(r) => self.pat_bind(&r.pat, name, t), |
| 3088 | Pat::Ident(i) if i.subpat.is_none() => { |
| 3089 | let b = i.ident.to_string(); |
| 3090 | self.line(&format!("let {}: {} = {}", ident(&b), t.render(), name)); |
| 3091 | self.bind(&b, t.clone()); |
| 3092 | Ok(()) |
| 3093 | } |
| 3094 | Pat::TupleStruct(ts) => { |
| 3095 | let fields = self.variant_fields(&ts.path, t)?; |
| 3096 | for (i, sub) in ts.elems.iter().enumerate() { |
| 3097 | let Some((fname, fty)) = fields.get(i) else { |
| 3098 | return Err(format!( |
| 3099 | "pattern binds {} field(s) but the variant has {}", |
| 3100 | ts.elems.len(), |
| 3101 | fields.len() |
| 3102 | )); |
| 3103 | }; |
| 3104 | let access = format!("{}.{}", name, ident(fname)); |
| 3105 | self.pat_bind(sub, &access, fty)?; |
| 3106 | } |
| 3107 | Ok(()) |
| 3108 | } |
| 3109 | Pat::Struct(st) => { |
| 3110 | let fields = self.variant_fields(&st.path, t)?; |
| 3111 | for f in &st.fields { |
| 3112 | let syn::Member::Named(m) = &f.member else { |
| 3113 | return Err("unsupported struct pattern field".into()); |
| 3114 | }; |
| 3115 | let m = m.to_string(); |
| 3116 | let Some((fname, fty)) = fields.iter().find(|(f, _)| f.ends_with(&m)) else { |
| 3117 | return Err(format!("unknown field `{m}` in pattern")); |
| 3118 | }; |
| 3119 | let access = format!("{}.{}", name, ident(fname)); |
| 3120 | self.pat_bind(&f.pat, &access, fty)?; |
| 3121 | } |
| 3122 | Ok(()) |
| 3123 | } |
| 3124 | _ => Err("unsupported `match` pattern".into()), |
| 3125 | } |
| 3126 | } |
| 3127 | |
| 3128 | /// The payload fields a variant pattern destructures. |
| 3129 | fn variant_fields( |
| 3130 | &self, |
| 3131 | path: &syn::Path, |
| 3132 | t: &Nim, |
| 3133 | ) -> Result<Vec<(String, Nim)>, String> { |
| 3134 | let last = path_name(path); |
| 3135 | // `Ok`/`Err`/`Some` read the prelude's own field names. |
| 3136 | if let Nim::Named(n, a) = t { |
| 3137 | match (n.as_str(), last.as_str()) { |
| 3138 | ("Result", "Ok") if a.len() == 2 => return Ok(vec![("val".into(), a[0].clone())]), |
| 3139 | ("Result", "Err") if a.len() == 2 => return Ok(vec![("err".into(), a[1].clone())]), |
| 3140 | ("Option", "Some") if a.len() == 1 => return Ok(vec![("val".into(), a[0].clone())]), |
| 3141 | _ => {} |
| 3142 | } |
| 3143 | } |
| 3144 | let Some((def, v)) = self.resolve_variant(path) else { |
| 3145 | return Err(format!("`{last}` is not a known enum variant")); |
| 3146 | }; |
| Add generics; transpile the part of cosmic-theme that is reachable ff34e1b nandithebull 7h ago | 3147 | let fields = def.get(&v).map(|v| v.fields.clone()).unwrap_or_default(); |
| 3148 | // The variant's payload is declared in the enum's own parameters; the |
| 3149 | // scrutinee says what they are here. |
| 3150 | Ok(fields |
| 3151 | .into_iter() |
| 3152 | .map(|(n, ft)| (n, self.subst_type_args(&def.name, t, ft))) |
| 3153 | .collect()) |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 3154 | } |
| 3155 | |
| 3156 | fn arm_body(&mut self, body: &Expr) -> Result<(), String> { |
| 3157 | self.indent += 1; |
| 3158 | let before = self.out.len(); |
| 3159 | self.indent -= 1; |
| 3160 | self.arm_body_at(body, before) |
| 3161 | } |
| 3162 | |
| 3163 | fn arm_body_at(&mut self, body: &Expr, before: usize) -> Result<(), String> { |
| 3164 | match body { |
| 3165 | Expr::Block(b) => self.nested_block(&b.block)?, |
| 3166 | other => { |
| 3167 | self.indent += 1; |
| 3168 | // An arm's value is the `match`'s value, so it is typed by |
| 3169 | // whatever the `match` is being assigned to -- without which |
| 3170 | // an `Ok(..)` arm has no way to know its `Result<T, E>`. |
| 3171 | let want = self.target.clone().and_then(|(_, t)| t); |
| 3172 | let v = match (want, expressible(other)) { |
| 3173 | (Some(t), true) => Some(self.expr_at(other, Some(&t))?), |
| 3174 | _ => self.expr_stmt(other)?, |
| 3175 | }; |
| 3176 | self.emit_tail(v); |
| 3177 | self.indent -= 1; |
| 3178 | } |
| 3179 | } |
| 3180 | if self.out.len() == before { |
| 3181 | self.indent += 1; |
| 3182 | self.line("discard"); |
| 3183 | self.indent -= 1; |
| 3184 | } |
| 3185 | Ok(()) |
| 3186 | } |
| 3187 | |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 3188 | fn pat_labels(&mut self, p: &Pat, expect: Option<&Nim>) -> Result<Vec<String>, String> { |
| 3189 | match p { |
| 3190 | Pat::Lit(l) => Ok(vec![self.lit_at(&l.lit, expect)?.code]), |
| 3191 | Pat::Or(o) => { |
| 3192 | let mut out = Vec::new(); |
| 3193 | for p in &o.cases { |
| 3194 | out.extend(self.pat_labels(p, expect)?); |
| 3195 | } |
| 3196 | Ok(out) |
| 3197 | } |
| 3198 | Pat::Range(r) => { |
| 3199 | let lo = r.start.as_ref().ok_or("open-ended range pattern")?; |
| 3200 | let hi = r.end.as_ref().ok_or("open-ended range pattern")?; |
| 3201 | let (lo, hi) = (self.expr_at(lo, expect)?, self.expr_at(hi, expect)?); |
| 3202 | let op = match r.limits { |
| 3203 | syn::RangeLimits::HalfOpen(_) => "..<", |
| 3204 | syn::RangeLimits::Closed(_) => "..", |
| 3205 | }; |
| 3206 | Ok(vec![format!("{} {} {}", lo.code, op, hi.code)]) |
| 3207 | } |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 3208 | Pat::Path(pp) => { |
| 3209 | if let Some((def, v)) = self.resolve_variant(&pp.path) { |
| 3210 | return Ok(vec![if def.simple { |
| 3211 | format!("{}.{}", ident(&def.name), ident(&v)) |
| 3212 | } else { |
| 3213 | def.kind_ident(&v) |
| 3214 | }]); |
| 3215 | } |
| 3216 | Ok(vec![ident(&path_name(&pp.path))]) |
| 3217 | } |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 3218 | _ => Err("unsupported `match` pattern; only literals, ranges, `|` \ |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 3219 | alternatives, enum variants and `_` are implemented" |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 3220 | .into()), |
| 3221 | } |
| 3222 | } |
| 3223 | |
| 3224 | // --------------------------------------------------------- expressions |
| 3225 | |
| 3226 | fn expr(&mut self, e: &Expr) -> Result<Val, String> { |
| 3227 | self.expr_at(e, None) |
| 3228 | } |
| 3229 | |
| 3230 | /// Lower `e`, with the type the surrounding code expects of it. |
| 3231 | /// |
| 3232 | /// Rust infers an unsuffixed integer literal's type from its context and |
| 3233 | /// falls back to `i32`; Nim falls back to 64-bit `int`. Carrying the |
| 3234 | /// expected type down to the literal is what makes `let x: u8 = 255` and |
| 3235 | /// `x.wrapping_add(100)` mean the same thing on both sides. Without it the |
| 3236 | /// widths silently diverge, which is exactly the class of bug this |
| 3237 | /// project refuses to ship. |
| 3238 | fn expr_at(&mut self, e: &Expr, expect: Option<&Nim>) -> Result<Val, String> { |
| 3239 | match e { |
| 3240 | Expr::Lit(l) => self.lit_at(&l.lit, expect), |
| 3241 | Expr::Path(p) => { |
| 3242 | let name = path_name(&p.path); |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 3243 | if name == "None" { |
| 3244 | return Ok(Val::new(self.none_of(expect), expect.cloned())); |
| 3245 | } |
| Lower the `log` facade, and add explicit enum discriminants 12c0a01 nandithebull 6h ago | 3246 | // `log::Level` and `log::LevelFilter` come from the facade |
| 3247 | // shim, under names no crate can collide with. |
| 3248 | if let Some(q) = p.path.segments.iter().rev().nth(1).map(|s| s.ident.to_string()) { |
| 3249 | if (q == "Level" || q == "LevelFilter") && !self.enums.contains_key(&q) { |
| 3250 | let pre = if q == "Level" { "rsLvl" } else { "rsFlt" }; |
| 3251 | let t = if q == "Level" { "RsLogLevel" } else { "RsLogFilter" }; |
| 3252 | if q == "LevelFilter" && name == "Off" { |
| 3253 | return Ok(Val::new("rsFltOff", Some(Nim::Prim(t.into())))); |
| 3254 | } |
| 3255 | if matches!(name.as_str(), "Error" | "Warn" | "Info" | "Debug" | "Trace") { |
| 3256 | return Ok(Val::new( |
| 3257 | format!("{pre}{name}"), |
| 3258 | Some(Nim::Prim(t.into())), |
| 3259 | )); |
| 3260 | } |
| 3261 | } |
| 3262 | } |
| 3263 | |
| Lower `bitflags!` directly, checked against the real crate af6e50f nandithebull 7h ago | 3264 | // `Perms::READ`: a constant of a `bitflags!` type. |
| 3265 | if let Some(q) = p.path.segments.iter().rev().nth(1).map(|s| s.ident.to_string()) { |
| 3266 | let q = if q == "Self" { |
| 3267 | self.self_ty.as_ref().map(type_name).unwrap_or(q) |
| 3268 | } else { |
| 3269 | q |
| 3270 | }; |
| 3271 | if let Some(c) = self.flag_consts.get(&(q.clone(), name.clone())) { |
| 3272 | return Ok(Val::new(c.clone(), Some(Nim::Named(q, vec![])))); |
| 3273 | } |
| 3274 | } |
| 3275 | |
| Add associated types and consts, and test whether the blocker stack bottoms out 8354895 nandithebull 7h ago | 3276 | // `Grid::BORDER`: a `const` declared inside an `impl`. |
| 3277 | if let Some(q) = p.path.segments.iter().rev().nth(1).map(|s| s.ident.to_string()) { |
| 3278 | let q = if q == "Self" { |
| 3279 | self.self_ty.as_ref().map(type_name).unwrap_or(q) |
| 3280 | } else { |
| 3281 | q |
| 3282 | }; |
| 3283 | if let Some((nim, t)) = self.assoc_consts.get(&(q, name.clone())) { |
| 3284 | return Ok(Val::new(nim.clone(), Some(t.clone()))); |
| 3285 | } |
| 3286 | } |
| 3287 | |
| Add generics; transpile the part of cosmic-theme that is reachable ff34e1b nandithebull 7h ago | 3288 | // `i32::MAX` and friends: an associated const on a primitive. |
| 3289 | if matches!(name.as_str(), "MAX" | "MIN") { |
| 3290 | if let Some(q) = p.path.segments.iter().rev().nth(1) { |
| 3291 | if let Some(t @ Nim::Prim(_)) = ty::prim(&q.ident.to_string()) { |
| 3292 | if t.is_integer() { |
| 3293 | let f = if name == "MAX" { "high" } else { "low" }; |
| 3294 | return Ok(Val::new( |
| 3295 | format!("{}({})", f, t.render()), |
| 3296 | Some(t), |
| 3297 | )); |
| 3298 | } |
| 3299 | } |
| 3300 | } |
| 3301 | } |
| 3302 | |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 3303 | // A unit struct used as a value: `fmt::Error`, or a `struct S;` |
| 3304 | // declared here. In Nim that is a constructor call. |
| 3305 | if p.path.segments.len() > 1 { |
| 3306 | let ty = syn::Type::Path(syn::TypePath { attrs: Vec::new(), qself: None, path: p.path.clone() }); |
| 3307 | if let Ok(Nim::Prim(n)) = ty::map(&ty) { |
| 3308 | if n == "FmtError" { |
| 3309 | return Ok(Val::new("FmtError()", Some(Nim::Prim(n)))); |
| 3310 | } |
| 3311 | } |
| 3312 | } |
| 3313 | if self.structs.get(&name).is_some_and(|f| f.is_empty()) { |
| 3314 | return Ok(Val::new( |
| 3315 | format!("{}()", ident(&name)), |
| 3316 | Some(Nim::Named(name.clone(), vec![])), |
| 3317 | )); |
| 3318 | } |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 3319 | // A unit enum variant used as a value: `Error::InvalidLength`. |
| 3320 | if let Some((def, v)) = self.resolve_variant(&p.path) { |
| Add generics; transpile the part of cosmic-theme that is reachable ff34e1b nandithebull 7h ago | 3321 | let (ty, targs) = self.variant_type(&def, expect)?; |
| 3322 | return Ok(if def.simple && targs.is_empty() { |
| 3323 | Val::new(format!("{}.{}", ident(&def.name), ident(&v)), Some(ty)) |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 3324 | } else { |
| Add generics; transpile the part of cosmic-theme that is reachable ff34e1b nandithebull 7h ago | 3325 | // A unit variant of a generic enum has no argument to |
| 3326 | // infer the parameters from, so they are written out. |
| 3327 | Val::new( |
| 3328 | format!("{}{}()", def.ctor_ident(&v), targs), |
| 3329 | Some(ty), |
| 3330 | ) |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 3331 | }); |
| 3332 | } |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 3333 | // A `for` binding that stands for an element of the container |
| 3334 | // it came from: using it must read (and assigning through it |
| 3335 | // must write) that element, not a copy. |
| 3336 | if let Some(a) = self.lookup_alias(&name) { |
| 3337 | return Ok(match a { |
| 3338 | Alias::Value { code, ty } => Val::new(code, ty), |
| 3339 | // A window *is* a slice; as a value it is the view it |
| 3340 | // denotes, which is what Rust's `&[T]` means too. |
| 3341 | Alias::Window { code, off, len, elem } => Val::new( |
| 3342 | format!("{}.toOpenArray({}, {} + {} - 1)", code, off, off, len), |
| 3343 | elem.map(|e| Nim::OpenArray(Box::new(e))), |
| 3344 | ), |
| Transpile a second crate, adler2, to test whether any of this generalises 5fdd5be nandithebull 8h ago | 3345 | // An iterator is not a value here: it is consumed by a |
| 3346 | // `for`, or asked for its `.remainder()`. |
| 3347 | Alias::Iterator(_) => { |
| 3348 | return Err(format!( |
| 3349 | "`{name}` is an iterator; it can be iterated or asked \ |
| 3350 | for its `remainder()`, but not used as a value" |
| 3351 | )) |
| 3352 | } |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 3353 | }); |
| 3354 | } |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 3355 | if let Some(t) = self.lookup(&name) { |
| 3356 | return Ok(Val::new(ident(&name), Some(t))); |
| 3357 | } |
| 3358 | // A top-level function used as a value, e.g. passed to a |
| 3359 | // parameter of `impl Fn(..)` type. |
| Add closures and unsafe; base16ct's lower.rs and upper.rs go through 0a375d8 nandithebull 9h ago | 3360 | if let Some(k) = self.resolve_fn(&p.path) { |
| 3361 | let sig = &self.fns[&k]; |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 3362 | let t = Nim::Proc(sig.params.clone(), Box::new(sig.ret.clone())); |
| Add closures and unsafe; base16ct's lower.rs and upper.rs go through 0a375d8 nandithebull 9h ago | 3363 | return Ok(Val::new(self.fn_name(&k.0, &k.1), Some(t))); |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 3364 | } |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 3365 | Ok(Val::new(ident(&name), None)) |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 3366 | } |
| 3367 | Expr::Paren(p) => { |
| 3368 | let v = self.expr_at(&p.expr, expect)?; |
| 3369 | Ok(Val::new(format!("({})", v.code), v.ty)) |
| 3370 | } |
| 3371 | Expr::Group(g) => self.expr_at(&g.expr, expect), |
| 3372 | // `&x` is a value in Nim; `&mut x` in an argument position binds to |
| 3373 | // a `var` parameter, which is also just `x` at the call site. |
| 3374 | Expr::Reference(r) => self.expr_at(&r.expr, expect), |
| 3375 | Expr::Unary(u) => self.unary(u, expect), |
| 3376 | Expr::Binary(b) => self.binary(b, expect), |
| 3377 | Expr::Cast(c) => self.cast(c), |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 3378 | Expr::Index(i) if matches!(&*i.index, Expr::Range(_)) => { |
| 3379 | let Expr::Range(r) = &*i.index else { unreachable!() }; |
| 3380 | let base = self.expr(&i.expr)?; |
| 3381 | let lo = match &r.start { |
| 3382 | Some(e) => format!("int({})", self.expr(e)?.code), |
| 3383 | None => "0".into(), |
| 3384 | }; |
| 3385 | // Nim's `toOpenArray` takes an inclusive upper bound. |
| 3386 | let hi = match (&r.end, r.limits) { |
| 3387 | (Some(e), syn::RangeLimits::HalfOpen(_)) => { |
| 3388 | format!("int({}) - 1", self.expr(e)?.code) |
| 3389 | } |
| 3390 | (Some(e), syn::RangeLimits::Closed(_)) => { |
| 3391 | format!("int({})", self.expr(e)?.code) |
| 3392 | } |
| 3393 | (None, _) => format!("{}.len - 1", base.code), |
| 3394 | }; |
| 3395 | let elem = elem_of(&base.ty) |
| 3396 | .ok_or("cannot infer the element type of this slice")?; |
| 3397 | Ok(Val::new( |
| 3398 | format!("{}.toOpenArray({}, {})", base.code, lo, hi), |
| 3399 | Some(Nim::OpenArray(Box::new(elem))), |
| 3400 | )) |
| 3401 | } |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 3402 | Expr::Index(i) => { |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 3403 | if let Some(Alias::Window { code, off, elem, .. }) = self.window_of(&i.expr) { |
| 3404 | let idx = self.expr(&i.index)?; |
| 3405 | return Ok(Val::new( |
| 3406 | format!("{}[{} + int({})]", code, off, idx.code), |
| 3407 | elem, |
| 3408 | )); |
| 3409 | } |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 3410 | let base = self.expr(&i.expr)?; |
| 3411 | let idx = self.expr(&i.index)?; |
| 3412 | // Rust indexes with usize; Nim wants an `int`, and a `uint` |
| 3413 | // index is a type error there rather than a silent conversion. |
| 3414 | let idx_code = match &idx.ty { |
| 3415 | Some(t) if t.is_unsigned() => format!("int({})", idx.code), |
| 3416 | _ => idx.code.clone(), |
| 3417 | }; |
| 3418 | let elem = match base.ty.clone() { |
| 3419 | Some(Nim::Seq(t)) | Some(Nim::OpenArray(t)) | Some(Nim::Array(_, t)) => Some(*t), |
| 3420 | Some(Nim::Prim(p)) if p == "string" => Some(Nim::Prim("char".into())), |
| 3421 | _ => None, |
| 3422 | }; |
| 3423 | Ok(Val::new(format!("{}[{}]", base.code, idx_code), elem)) |
| 3424 | } |
| 3425 | Expr::Field(f) => { |
| 3426 | let base = self.expr(&f.base)?; |
| 3427 | let name = match &f.member { |
| 3428 | syn::Member::Named(n) => n.to_string(), |
| 3429 | syn::Member::Unnamed(i) => format!("f{}", i.index), |
| 3430 | }; |
| 3431 | let t = match &base.ty { |
| Add generics; transpile the part of cosmic-theme that is reachable ff34e1b nandithebull 7h ago | 3432 | Some(bt @ Nim::Named(s, _)) => self |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 3433 | .structs |
| 3434 | .get(s) |
| 3435 | .and_then(|fs| fs.iter().find(|(f, _)| *f == name)) |
| Add generics; transpile the part of cosmic-theme that is reachable ff34e1b nandithebull 7h ago | 3436 | .map(|(_, t)| self.subst_type_args(s, bt, t.clone())), |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 3437 | _ => None, |
| 3438 | }; |
| 3439 | Ok(Val::new(format!("{}.{}", base.code, ident(&name)), t)) |
| 3440 | } |
| Add closures and unsafe; base16ct's lower.rs and upper.rs go through 0a375d8 nandithebull 9h ago | 3441 | // `unsafe` is a permission marker, not a semantic change: it does |
| 3442 | // not alter what the enclosed operations mean. So the block is |
| 3443 | // transparent here, and each operation inside still goes through |
| 3444 | // the ordinary lowering -- and is still rejected if it has no |
| 3445 | // faithful mapping. |
| 3446 | Expr::Unsafe(u) => match single_expr(&u.block) { |
| 3447 | Some(e) => self.expr_at(e, expect), |
| 3448 | None => Err("an `unsafe` block used as a value must be a single \ |
| 3449 | expression" |
| 3450 | .into()), |
| 3451 | }, |
| 3452 | Expr::Closure(c) => self.closure(c, expect), |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 3453 | Expr::Try(t) => self.try_op(t), |
| 3454 | Expr::Call(c) => self.call(c, expect), |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 3455 | Expr::MethodCall(m) => self.method(m, expect), |
| Add closures and unsafe; base16ct's lower.rs and upper.rs go through 0a375d8 nandithebull 9h ago | 3456 | Expr::Macro(m) if path_name(&m.mac.path) == "vec" => { |
| 3457 | // `vec![..]`'s elements take their type from the annotation on |
| 3458 | // the binding, exactly as Rust's would. |
| 3459 | let want = match expect { |
| 3460 | Some(Nim::Seq(e)) | Some(Nim::OpenArray(e)) => Some((**e).clone()), |
| 3461 | _ => None, |
| 3462 | }; |
| 3463 | let saved = std::mem::replace(&mut self.vec_expect, want.clone()); |
| 3464 | let code = self.macro_call(&m.mac); |
| 3465 | self.vec_expect = saved; |
| 3466 | let code = code?; |
| 3467 | let ty = match want { |
| 3468 | Some(e) => Some(Nim::Seq(Box::new(e))), |
| 3469 | None => self.vec_elem(&m.mac)?.map(|e| Nim::Seq(Box::new(e))), |
| 3470 | }; |
| 3471 | Ok(Val::new(code, ty)) |
| 3472 | } |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 3473 | Expr::Macro(m) => { |
| Add display.rs and the alloc half: all of base16ct now goes through afb2a6e nandithebull 9h ago | 3474 | let is_write = matches!(path_name(&m.mac.path).as_str(), "write" | "writeln"); |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 3475 | let code = self.macro_call(&m.mac)?; |
| Add display.rs and the alloc half: all of base16ct now goes through afb2a6e nandithebull 9h ago | 3476 | // A formatter write is a statement that appends, not a value. |
| 3477 | let ty = if is_write { Some(Nim::Unit) } else { None }; |
| 3478 | Ok(Val::new(code, ty)) |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 3479 | } |
| 3480 | Expr::Struct(s) => { |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 3481 | if s.rest.is_some() { |
| 3482 | return Err("struct update syntax `..rest` is not implemented yet".into()); |
| 3483 | } |
| 3484 | // `Shape::Rect { w: 3, h: 5 }` is a struct-shaped *enum variant*, |
| 3485 | // which is constructed positionally in Nim. |
| 3486 | if let Some((def, v)) = self.resolve_variant(&s.path) { |
| 3487 | let fields = def.get(&v).map(|v| v.fields.clone()).unwrap_or_default(); |
| 3488 | let mut args = vec![String::new(); fields.len()]; |
| 3489 | for f in &s.fields { |
| 3490 | let syn::Member::Named(m) = &f.member else { |
| 3491 | return Err("unsupported enum variant field".into()); |
| 3492 | }; |
| 3493 | let want = format!("{}_{}", v, m); |
| 3494 | let i = fields |
| 3495 | .iter() |
| 3496 | .position(|(n, _)| *n == want) |
| 3497 | .ok_or_else(|| format!("`{}::{}` has no field `{m}`", def.name, v))?; |
| 3498 | args[i] = self.expr_at(&f.expr, Some(&fields[i].1))?.code; |
| 3499 | } |
| 3500 | if let Some(i) = args.iter().position(|a| a.is_empty()) { |
| 3501 | return Err(format!( |
| 3502 | "`{}::{}` is missing field `{}`", |
| 3503 | def.name, v, fields[i].0 |
| 3504 | )); |
| 3505 | } |
| 3506 | return Ok(Val::new( |
| 3507 | format!("{}({})", def.ctor_ident(&v), args.join(", ")), |
| 3508 | Some(Nim::Named(def.name.clone(), vec![])), |
| 3509 | )); |
| 3510 | } |
| Add generics; transpile the part of cosmic-theme that is reachable ff34e1b nandithebull 7h ago | 3511 | // `Self { .. }` inside an `impl` names the type being |
| 3512 | // implemented, and its fields are that type's fields. |
| 3513 | let name = match path_name(&s.path).as_str() { |
| 3514 | "Self" => self |
| 3515 | .self_ty |
| 3516 | .as_ref() |
| 3517 | .map(type_name) |
| 3518 | .ok_or("`Self` outside an `impl` block")?, |
| 3519 | other => other.to_string(), |
| 3520 | }; |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 3521 | let mut parts = Vec::new(); |
| 3522 | for f in &s.fields { |
| 3523 | let fname = match &f.member { |
| 3524 | syn::Member::Named(n) => n.to_string(), |
| 3525 | syn::Member::Unnamed(i) => format!("f{}", i.index), |
| 3526 | }; |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 3527 | let want = self |
| 3528 | .structs |
| 3529 | .get(&name) |
| 3530 | .and_then(|fs| fs.iter().find(|(n, _)| *n == fname)) |
| 3531 | .map(|(_, t)| t.clone()); |
| 3532 | let v = self.expr_at(&f.expr, want.as_ref())?; |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 3533 | parts.push(format!("{}: {}", ident(&fname), v.code)); |
| 3534 | } |
| Add generics; transpile the part of cosmic-theme that is reachable ff34e1b nandithebull 7h ago | 3535 | // Nim cannot infer an object's generic parameters from a |
| 3536 | // constructor's field values, so they are written out. |
| 3537 | let gp = self.type_generics.get(&name).cloned().unwrap_or_default(); |
| 3538 | let ty = if gp.is_empty() { |
| 3539 | Nim::Named(name.clone(), vec![]) |
| 3540 | } else { |
| 3541 | match expect { |
| 3542 | Some(Nim::Named(n, a)) if *n == name && a.len() == gp.len() => { |
| 3543 | Nim::Named(name.clone(), a.clone()) |
| 3544 | } |
| 3545 | _ => { |
| 3546 | return Err(format!( |
| 3547 | "`{name} {{ .. }}` is generic, and Nim cannot infer \ |
| 3548 | its parameters from the field values; annotate the \ |
| 3549 | binding or the return type" |
| 3550 | )) |
| 3551 | } |
| 3552 | } |
| 3553 | }; |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 3554 | Ok(Val::new( |
| Add generics; transpile the part of cosmic-theme that is reachable ff34e1b nandithebull 7h ago | 3555 | format!("{}({})", ty.render(), parts.join(", ")), |
| 3556 | Some(ty), |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 3557 | )) |
| 3558 | } |
| 3559 | Expr::Array(a) => { |
| 3560 | let mut parts = Vec::new(); |
| 3561 | let mut elem = match expect { |
| 3562 | Some(Nim::Array(_, t)) | Some(Nim::Seq(t)) | Some(Nim::OpenArray(t)) => { |
| 3563 | Some((**t).clone()) |
| 3564 | } |
| 3565 | _ => None, |
| 3566 | }; |
| 3567 | for e in &a.elems { |
| 3568 | let want = elem.clone(); |
| 3569 | let v = self.expr_at(e, want.as_ref())?; |
| 3570 | elem = elem.or(v.ty.clone()); |
| 3571 | parts.push(v.code); |
| 3572 | } |
| 3573 | let t = elem.map(|t| Nim::Array(a.elems.len(), Box::new(t))); |
| 3574 | Ok(Val::new(format!("[{}]", parts.join(", ")), t)) |
| 3575 | } |
| 3576 | Expr::Repeat(r) => { |
| Transpile a second crate, adler2, to test whether any of this generalises 5fdd5be nandithebull 8h ago | 3577 | // `[0; 4]` is an array in Rust. Nim distinguishes a fixed-size |
| 3578 | // array from a `seq`, so the expected type decides which, and |
| 3579 | // an array needs its elements written out. |
| 3580 | let want_elem = match expect { |
| 3581 | Some(Nim::Array(_, e)) | Some(Nim::Seq(e)) | Some(Nim::OpenArray(e)) => { |
| 3582 | Some((**e).clone()) |
| 3583 | } |
| 3584 | _ => None, |
| 3585 | }; |
| 3586 | let v = self.expr_at(&r.expr, want_elem.as_ref())?; |
| 3587 | if let Some(Nim::Array(n, _)) = expect { |
| 3588 | let elems: Vec<String> = (0..*n).map(|_| v.code.clone()).collect(); |
| 3589 | let t = v.ty.clone().map(|t| Nim::Array(*n, Box::new(t))); |
| 3590 | return Ok(Val::new(format!("[{}]", elems.join(", ")), t)); |
| 3591 | } |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 3592 | let n = self.expr(&r.len)?; |
| 3593 | let t = v.ty.clone().map(|t| Nim::Seq(Box::new(t))); |
| 3594 | Ok(Val::new(format!("newSeqWith(int({}), {})", n.code, v.code), t)) |
| 3595 | } |
| 3596 | Expr::Tuple(t) if t.elems.is_empty() => Ok(Val::new("", Some(Nim::Unit))), |
| 3597 | Expr::Tuple(t) => { |
| 3598 | let mut parts = Vec::new(); |
| 3599 | let mut tys = Vec::new(); |
| 3600 | for e in &t.elems { |
| 3601 | let v = self.expr(e)?; |
| 3602 | tys.push(v.ty.clone()); |
| 3603 | parts.push(v.code); |
| 3604 | } |
| 3605 | let ty = tys |
| 3606 | .iter() |
| 3607 | .cloned() |
| 3608 | .collect::<Option<Vec<_>>>() |
| 3609 | .map(Nim::Tuple); |
| 3610 | Ok(Val::new(format!("({})", parts.join(", ")), ty)) |
| 3611 | } |
| 3612 | // `if` and `match` are expressions in both languages, but only |
| 3613 | // when every arm is itself a single expression. |
| 3614 | Expr::If(i) => self.if_expr(i, expect), |
| Expand `$(..)` repetition in macro_rules 3d4a7d2 nandithebull 6h ago | 3615 | // A block with statements used as a value: the statements are |
| 3616 | // emitted ahead of the line being built and the block's trailing |
| 3617 | // expression becomes the value. Every caller lowers its |
| 3618 | // sub-expressions before emitting its own line, which is what |
| 3619 | // makes that ordering hold. |
| 3620 | Expr::Block(b) |
| 3621 | if b.label.is_none() |
| 3622 | && b.block.stmts.len() > 1 |
| 3623 | && matches!(b.block.stmts.last(), Some(Stmt::Expr(_, None))) => |
| 3624 | { |
| 3625 | if self.in_loop_cond { |
| 3626 | return Err("a block expression in a loop condition is not \ |
| 3627 | implemented yet: its statements would run once, \ |
| 3628 | before the loop" |
| 3629 | .into()); |
| 3630 | } |
| 3631 | // Nim's `block:` is an expression too, so the statements get |
| 3632 | // their own scope rather than being hoisted into the enclosing |
| 3633 | // one -- which would collide if the same block is written |
| 3634 | // twice, as a macro expanded at two call sites is. |
| 3635 | let tmp = self.fresh("Blk"); |
| 3636 | self.line(&format!("let {} = block:", tmp)); |
| 3637 | self.indent += 1; |
| 3638 | self.push_scope(); |
| 3639 | let saved = self.target.take(); |
| 3640 | let before = self.out.len(); |
| 3641 | let tail = self.block_body_at(&b.block, expect)?; |
| 3642 | let ty = tail.as_ref().and_then(|v| v.ty.clone()); |
| 3643 | match tail { |
| 3644 | Some(v) => { |
| 3645 | let code = v.code.clone(); |
| 3646 | self.line(&code); |
| 3647 | } |
| 3648 | None => { |
| 3649 | return Err( |
| 3650 | "a block used as a value needs a trailing expression".into() |
| 3651 | ) |
| 3652 | } |
| 3653 | } |
| 3654 | let _ = before; |
| 3655 | self.target = saved; |
| 3656 | self.pop_scope(); |
| 3657 | self.indent -= 1; |
| 3658 | Ok(Val::new(tmp, ty)) |
| 3659 | } |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 3660 | Expr::Block(b) if b.block.stmts.len() == 1 => { |
| 3661 | if let Some(Stmt::Expr(e, None)) = b.block.stmts.first() { |
| 3662 | self.expr_at(e, expect) |
| 3663 | } else { |
| 3664 | Err("block expression with statements in value position is not implemented yet".into()) |
| 3665 | } |
| 3666 | } |
| 3667 | other => Err(format!( |
| 3668 | "unsupported expression in value position: {}", |
| 3669 | expr_kind(other) |
| 3670 | )), |
| 3671 | } |
| 3672 | } |
| 3673 | |
| 3674 | fn if_expr(&mut self, i: &syn::ExprIf, expect: Option<&Nim>) -> Result<Val, String> { |
| 3675 | let (Some(then), Some((_, els))) = (single_expr(&i.then_branch), &i.else_branch) else { |
| 3676 | return Err( |
| 3677 | "an `if` used as a value must have an `else` and single-expression arms".into(), |
| 3678 | ); |
| 3679 | }; |
| 3680 | let c = self.expr(&i.cond)?; |
| 3681 | let t = self.expr_at(then, expect)?; |
| 3682 | let want = expect.cloned().or_else(|| t.ty.clone()); |
| 3683 | let e = match &**els { |
| 3684 | Expr::Block(b) => match single_expr(&b.block) { |
| 3685 | Some(x) => self.expr_at(x, want.as_ref())?, |
| 3686 | None => return Err("an `if` used as a value must have single-expression arms".into()), |
| 3687 | }, |
| 3688 | other => self.expr_at(other, want.as_ref())?, |
| 3689 | }; |
| 3690 | let ty = t.ty.clone().or(e.ty.clone()); |
| 3691 | Ok(Val::new( |
| 3692 | format!("(if {}: {} else: {})", c.code, t.code, e.code), |
| 3693 | ty, |
| 3694 | )) |
| 3695 | } |
| 3696 | |
| 3697 | fn lit_at(&mut self, l: &Lit, expect: Option<&Nim>) -> Result<Val, String> { |
| 3698 | match l { |
| 3699 | Lit::Int(i) => { |
| 3700 | let suffix = i.suffix(); |
| 3701 | if let Some(why) = ty::rejected(suffix) { |
| 3702 | return Err(format!("integer literal `{}`: {}", i, why)); |
| 3703 | } |
| 3704 | let digits = i.base10_digits().to_string(); |
| 3705 | // Rust's default for an unconstrained integer literal is i32. |
| 3706 | // Nim's is `int` (64-bit). Making the width explicit is what |
| 3707 | // keeps overflow behaviour the same on both sides. |
| 3708 | let t = if suffix.is_empty() { |
| 3709 | match expect { |
| 3710 | Some(t) if t.is_integer() => t.clone(), |
| 3711 | // Rust's fallback for an otherwise-unconstrained |
| 3712 | // integer literal. |
| 3713 | _ => Nim::Prim("int32".into()), |
| 3714 | } |
| 3715 | } else { |
| 3716 | ty::prim(suffix).ok_or_else(|| format!("unknown literal suffix `{suffix}`"))? |
| 3717 | }; |
| 3718 | Ok(Val::new(format!("{}'{}", digits, nim_suffix(&t)?), Some(t))) |
| 3719 | } |
| 3720 | Lit::Float(f) => { |
| 3721 | let t = match f.suffix() { |
| 3722 | "" => match expect { |
| 3723 | Some(Nim::Prim(p)) if p == "float32" => Nim::Prim("float32".into()), |
| 3724 | _ => Nim::Prim("float64".into()), |
| 3725 | }, |
| 3726 | "f64" => Nim::Prim("float64".into()), |
| 3727 | "f32" => Nim::Prim("float32".into()), |
| 3728 | s => return Err(format!("unknown float suffix `{s}`")), |
| 3729 | }; |
| 3730 | let d = f.base10_digits(); |
| 3731 | let d = if d.contains('.') || d.contains('e') { d.to_string() } else { format!("{d}.0") }; |
| 3732 | Ok(Val::new(d, Some(t))) |
| 3733 | } |
| 3734 | Lit::Bool(b) => Ok(Val::new(b.value.to_string(), Some(Nim::Prim("bool".into())))), |
| 3735 | Lit::Str(s) => Ok(Val::new( |
| 3736 | fmt::nim_str(&s.value()), |
| 3737 | Some(Nim::Prim("string".into())), |
| 3738 | )), |
| 3739 | Lit::Char(c) => Ok(Val::new( |
| 3740 | format!("Rune({})", c.value() as u32), |
| 3741 | Some(Nim::Prim("Rune".into())), |
| 3742 | )), |
| 3743 | Lit::Byte(b) => Ok(Val::new( |
| 3744 | format!("{}'u8", b.value()), |
| 3745 | Some(Nim::Prim("uint8".into())), |
| 3746 | )), |
| 3747 | Lit::ByteStr(b) => { |
| 3748 | let bytes: Vec<String> = b.value().iter().map(|x| format!("{x}'u8")).collect(); |
| 3749 | Ok(Val::new( |
| 3750 | format!("@[{}]", bytes.join(", ")), |
| 3751 | Some(Nim::Seq(Box::new(Nim::Prim("uint8".into())))), |
| 3752 | )) |
| 3753 | } |
| 3754 | other => Err(format!("unsupported literal: {other:?}")), |
| 3755 | } |
| 3756 | } |
| 3757 | |
| 3758 | fn unary(&mut self, u: &syn::ExprUnary, expect: Option<&Nim>) -> Result<Val, String> { |
| 3759 | // `-128i8` is a literal in Rust, but `-(128'i8)` in Nim would overflow |
| 3760 | // the positive half of the range before the negation runs. Folding the |
| 3761 | // sign into the literal keeps `i8::MIN` and friends expressible. |
| 3762 | if let (UnOp::Neg(_), Expr::Lit(l)) = (&u.op, &*u.expr) { |
| 3763 | if matches!(l.lit, Lit::Int(_) | Lit::Float(_)) { |
| 3764 | let v = self.lit_at(&l.lit, expect)?; |
| 3765 | return Ok(Val::new(format!("-{}", v.code), v.ty)); |
| 3766 | } |
| 3767 | } |
| 3768 | let v = self.expr_at(&u.expr, expect)?; |
| 3769 | match u.op { |
| 3770 | UnOp::Neg(_) => Ok(Val::new(format!("(-{})", v.code), v.ty)), |
| 3771 | // Rust's `!` is logical on bool and bitwise-complement on integers. |
| 3772 | // Nim spells those `not` and `not` as well, so one mapping covers |
| 3773 | // both — but only because Nim overloads `not` the same way. |
| Lower `bitflags!` directly, checked against the real crate af6e50f nandithebull 7h ago | 3774 | UnOp::Not(_) => { |
| 3775 | if let Some(f) = self.op_proc(&v.ty, "not") { |
| 3776 | return Ok(Val::new(format!("{}({})", f, v.code), v.ty)); |
| 3777 | } |
| 3778 | Ok(Val::new(format!("(not {})", v.code), v.ty)) |
| 3779 | } |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 3780 | UnOp::Deref(_) => Ok(v), |
| 3781 | _ => Err("unsupported unary operator".into()), |
| 3782 | } |
| 3783 | } |
| 3784 | |
| 3785 | fn binary(&mut self, b: &syn::ExprBinary, expect: Option<&Nim>) -> Result<Val, String> { |
| 3786 | // A comparison's operands are unrelated to the `bool` it produces, so |
| 3787 | // the outer expectation is not passed through to them. |
| 3788 | let down = match b.op { |
| 3789 | BinOp::Eq(_) | BinOp::Ne(_) | BinOp::Lt(_) | BinOp::Le(_) | BinOp::Gt(_) |
| 3790 | | BinOp::Ge(_) | BinOp::And(_) | BinOp::Or(_) => None, |
| 3791 | _ => expect, |
| 3792 | }; |
| 3793 | let mut l = self.expr_at(&b.left, down)?; |
| 3794 | // Rust unifies the two operand types; propagating whichever side is |
| 3795 | // known to the other reproduces that, and disagreement then surfaces |
| 3796 | // as a Nim type error rather than as a silent width change. |
| 3797 | let mut r = self.expr_at(&b.right, l.ty.as_ref().or(down))?; |
| 3798 | if l.ty.is_none() && r.ty.is_some() { |
| 3799 | l = self.expr_at(&b.left, r.ty.as_ref())?; |
| 3800 | } |
| 3801 | let r = std::mem::replace(&mut r, Val::untyped("")); |
| Transpile a second crate, adler2, to test whether any of this generalises 5fdd5be nandithebull 8h ago | 3802 | // A binary operator on a user type goes to that type's own impl. |
| 3803 | if let Some(f) = self.op_proc(&l.ty, binary_symbol(&b.op)) { |
| 3804 | let want = self.op_param(&l.ty, binary_symbol(&b.op)); |
| 3805 | let r = self.expr_at(&b.right, want.as_ref())?; |
| 3806 | let ret = self |
| 3807 | .methods |
| 3808 | .get(&( |
| 3809 | type_name(l.ty.as_ref().unwrap()), |
| 3810 | op_method(binary_symbol(&b.op)).to_string(), |
| 3811 | )) |
| 3812 | .map(|s| s.ret.clone()); |
| 3813 | return Ok(Val::new(format!("{}({}, {})", f, l.code, r.code), ret)); |
| 3814 | } |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 3815 | let op = self.bin_op(&b.op, &l, &r)?; |
| 3816 | let ty = match b.op { |
| 3817 | BinOp::Eq(_) | BinOp::Ne(_) | BinOp::Lt(_) | BinOp::Le(_) | BinOp::Gt(_) |
| 3818 | | BinOp::Ge(_) | BinOp::And(_) | BinOp::Or(_) => Some(Nim::Prim("bool".into())), |
| 3819 | // Rust's shift takes its result type from the *left* operand, and |
| 3820 | // the right may be a different width entirely. |
| 3821 | BinOp::Shl(_) | BinOp::Shr(_) => l.ty.clone(), |
| 3822 | _ => l.ty.clone().or(r.ty.clone()), |
| 3823 | }; |
| 3824 | Ok(Val::new(format!("({} {} {})", l.code, op, r.code), ty)) |
| 3825 | } |
| 3826 | |
| 3827 | fn bin_op(&mut self, op: &BinOp, l: &Val, r: &Val) -> Result<&'static str, String> { |
| 3828 | Ok(match op { |
| 3829 | BinOp::Add(_) | BinOp::AddAssign(_) => "+", |
| 3830 | BinOp::Sub(_) | BinOp::SubAssign(_) => "-", |
| 3831 | BinOp::Mul(_) | BinOp::MulAssign(_) => "*", |
| 3832 | BinOp::Div(_) | BinOp::DivAssign(_) => { |
| 3833 | // Nim spells integer division `div`. Both languages truncate |
| 3834 | // toward zero, so once the right operator is chosen the |
| 3835 | // semantics match, including for negative operands. |
| 3836 | let t = l.ty.clone().or(r.ty.clone()).ok_or( |
| 3837 | "cannot tell integer from float division here; annotate the operands", |
| 3838 | )?; |
| 3839 | if t.is_integer() { "div" } else { "/" } |
| 3840 | } |
| 3841 | BinOp::Rem(_) | BinOp::RemAssign(_) => { |
| 3842 | let t = l.ty.clone().or(r.ty.clone()).ok_or( |
| 3843 | "cannot tell integer from float remainder here; annotate the operands", |
| 3844 | )?; |
| 3845 | if t.is_integer() { "mod" } else { return Err("float `%` is not implemented yet".into()) } |
| 3846 | } |
| 3847 | BinOp::And(_) => "and", |
| 3848 | BinOp::Or(_) => "or", |
| 3849 | // Nim's `and`/`or`/`xor` are bitwise on integers and logical on |
| 3850 | // bools, exactly as Rust's `&`/`|`/`^` are. |
| 3851 | BinOp::BitAnd(_) | BinOp::BitAndAssign(_) => "and", |
| 3852 | BinOp::BitOr(_) | BinOp::BitOrAssign(_) => "or", |
| 3853 | BinOp::BitXor(_) | BinOp::BitXorAssign(_) => "xor", |
| 3854 | // Settled empirically: Nim's `shr` on a signed integer is |
| 3855 | // arithmetic, matching Rust. See DESIGN.md. |
| 3856 | BinOp::Shl(_) | BinOp::ShlAssign(_) => "shl", |
| 3857 | BinOp::Shr(_) | BinOp::ShrAssign(_) => "shr", |
| 3858 | BinOp::Eq(_) => "==", |
| 3859 | BinOp::Ne(_) => "!=", |
| 3860 | BinOp::Lt(_) => "<", |
| 3861 | BinOp::Le(_) => "<=", |
| 3862 | BinOp::Gt(_) => ">", |
| 3863 | BinOp::Ge(_) => ">=", |
| 3864 | other => return Err(format!("unsupported binary operator {other:?}")), |
| 3865 | }) |
| 3866 | } |
| 3867 | |
| 3868 | fn cast(&mut self, c: &syn::ExprCast) -> Result<Val, String> { |
| 3869 | let v = self.expr(&c.expr)?; |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 3870 | let to = self.map_ty(&c.ty)?; |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 3871 | let from = v.ty.clone().ok_or_else(|| { |
| 3872 | format!( |
| 3873 | "cannot lower `as {}`: the source type is unknown, and `as` \ |
| 3874 | truncates, so the source width decides the result", |
| 3875 | to.render() |
| 3876 | ) |
| 3877 | })?; |
| 3878 | |
| 3879 | let code = match (&from, &to) { |
| 3880 | (f, t) if f.is_integer() && t.is_integer() => { |
| 3881 | // Rust's `as` between integers is a pure bit-width truncation |
| Prove byte-identity for base16ct by enumerating whole input domains 99b8376 nandithebull 8h ago | 3882 | // or sign-extension, never a range check. `cast` says exactly |
| 3883 | // that. (Nim's `T(x)` turns out to truncate here as well -- |
| 3884 | // see DESIGN.md item 5 -- but `cast` is the spelling that |
| 3885 | // means it rather than the one that happens to agree.) |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 3886 | format!("cast[{}]({})", t.render(), v.code) |
| 3887 | } |
| 3888 | (f, Nim::Prim(p)) if f.is_integer() && (p == "float64" || p == "float32") => { |
| 3889 | format!("{}({})", p, v.code) |
| 3890 | } |
| Lower the `log` facade, and add explicit enum discriminants 12c0a01 nandithebull 6h ago | 3891 | // The facade's level enums carry their Rust discriminants, so |
| 3892 | // `Level::Info as usize` is the ordinal. |
| 3893 | (Nim::Prim(p), t) |
| 3894 | if t.is_integer() && (p == "RsLogLevel" || p == "RsLogFilter") => |
| 3895 | { |
| 3896 | format!("{}(ord({}))", t.render(), v.code) |
| 3897 | } |
| 3898 | // A C-like enum's `as` yields its discriminant, which is its |
| 3899 | // ordinal in Nim. |
| 3900 | (Nim::Named(n, _), t) if t.is_integer() && self.enums.get(n).is_some_and(|d| d.simple) => { |
| 3901 | format!("{}(ord({}))", t.render(), v.code) |
| 3902 | } |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 3903 | (Nim::Prim(b), t) if b == "bool" && t.is_integer() => { |
| 3904 | format!("{}(ord({}))", t.render(), v.code) |
| 3905 | } |
| 3906 | (Nim::Prim(r), t) if r == "Rune" && t.is_integer() => { |
| 3907 | format!("cast[{}](int32({}))", t.render(), v.code) |
| 3908 | } |
| 3909 | (f, Nim::Prim(r)) if f.is_integer() && r == "Rune" => { |
| 3910 | format!("Rune(int32({}))", v.code) |
| 3911 | } |
| Lower `extern "C"` blocks to Nim importc; do not transpile libc 7db7991 nandithebull 6h ago | 3912 | // Pointer-to-pointer, and integer-to-pointer, are reinterpretations |
| 3913 | // in both languages. |
| 3914 | (Nim::Ptr(_) | Nim::ConstPtr(_), Nim::Ptr(_) | Nim::ConstPtr(_)) => { |
| 3915 | format!("cast[{}]({})", to.render(), v.code) |
| 3916 | } |
| 3917 | (f, Nim::Ptr(_) | Nim::ConstPtr(_)) if f.is_integer() => { |
| 3918 | format!("cast[{}]({})", to.render(), v.code) |
| 3919 | } |
| 3920 | (Nim::Ptr(_) | Nim::ConstPtr(_), t) if t.is_integer() => { |
| 3921 | format!("cast[{}]({})", t.render(), v.code) |
| 3922 | } |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 3923 | (Nim::Prim(a), Nim::Prim(b)) if a == b => v.code.clone(), |
| 3924 | (f, t) if matches!(f, Nim::Prim(p) if p.starts_with("float")) && t.is_integer() => { |
| 3925 | // Rust saturates float->int casts; Nim rounds and range-errors. |
| 3926 | // Not the same operation, so it is refused rather than mapped. |
| 3927 | return Err(format!( |
| 3928 | "`as {}` from a float: Rust saturates, Nim rounds and range-checks; \ |
| 3929 | no faithful mapping is implemented", |
| 3930 | t.render() |
| 3931 | )); |
| 3932 | } |
| 3933 | (f, t) => { |
| 3934 | return Err(format!( |
| 3935 | "unsupported cast from `{}` to `{}`", |
| 3936 | f.render(), |
| 3937 | t.render() |
| 3938 | )) |
| 3939 | } |
| 3940 | }; |
| 3941 | Ok(Val::new(code, Some(to))) |
| 3942 | } |
| 3943 | |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 3944 | /// Rust's `?`: return early on the error branch, otherwise yield the value. |
| 3945 | /// |
| 3946 | /// The early return is statements, not an expression, so they are emitted |
| 3947 | /// ahead of the line being built. Every caller lowers its sub-expressions |
| 3948 | /// before emitting its own line, which is what makes that ordering hold. |
| Add closures and unsafe; base16ct's lower.rs and upper.rs go through 0a375d8 nandithebull 9h ago | 3949 | /// The container, start offset, length and element type an expression |
| 3950 | /// denotes as a slice. A window alias contributes its own offset, so |
| 3951 | /// `dst.get_mut(..n)` followed by `.chunks_exact_mut(2)` indexes straight |
| 3952 | /// into the original buffer rather than through a rebuilt view. |
| 3953 | fn slice_parts( |
| 3954 | &mut self, |
| 3955 | e: &Expr, |
| 3956 | ) -> Result<(String, String, String, Option<Nim>), String> { |
| 3957 | if let Some(Alias::Window { code, off, len, elem }) = self.window_of(e) { |
| 3958 | return Ok((code, off, len, elem)); |
| 3959 | } |
| 3960 | let v = self.expr(e)?; |
| 3961 | let len = format!("{}.len", v.code); |
| 3962 | Ok((v.code, "0".to_string(), len, elem_of(&v.ty))) |
| 3963 | } |
| 3964 | |
| 3965 | /// Expand `opt.map(|x| body)` / `res.and_then(|x| body)` inline. |
| 3966 | fn map_closure( |
| 3967 | &mut self, |
| 3968 | what: &str, |
| 3969 | recv: &Val, |
| 3970 | kind: &str, |
| 3971 | targs: &[Nim], |
| 3972 | c: &syn::ExprClosure, |
| 3973 | ) -> Result<Val, String> { |
| 3974 | if c.capture.is_some() { |
| 3975 | return Err("a `move` closure captures by value; Nim's closures \ |
| 3976 | capture by reference, and the two are not the same" |
| 3977 | .into()); |
| 3978 | } |
| 3979 | if c.inputs.len() != 1 { |
| 3980 | return Err(format!("`.{what}()` takes a one-argument closure")); |
| 3981 | } |
| 3982 | let pname = match &c.inputs[0] { |
| 3983 | Pat::Ident(i) => i.ident.to_string(), |
| 3984 | Pat::Wild(_) => "unused0".into(), |
| 3985 | _ => return Err("only plain identifier closure parameters are supported".into()), |
| 3986 | }; |
| 3987 | |
| 3988 | let is_opt = kind == "Option"; |
| 3989 | let tmp = self.fresh("Map"); |
| 3990 | let recv_ty = Nim::Named(kind.to_string(), targs.to_vec()); |
| 3991 | self.line(&format!("let {}: {} = {}", tmp, recv_ty.render(), recv.code)); |
| 3992 | |
| 3993 | let body = match &*c.body { |
| 3994 | Expr::Block(b) => single_expr(&b.block) |
| 3995 | .ok_or("a closure body with statements is not implemented yet")?, |
| 3996 | other => other, |
| 3997 | }; |
| 3998 | self.push_scope(); |
| 3999 | // The parameter names the payload itself, so a view stays a view. |
| 4000 | self.bind_alias( |
| 4001 | &pname, |
| 4002 | Alias::Value { |
| 4003 | code: format!("{}.val", tmp), |
| 4004 | ty: Some(targs[0].clone()), |
| 4005 | }, |
| 4006 | ); |
| 4007 | let v = self.expr(body)?; |
| 4008 | self.pop_scope(); |
| 4009 | |
| 4010 | let inner = v |
| 4011 | .ty |
| 4012 | .clone() |
| 4013 | .ok_or_else(|| format!("cannot infer the result type of `.{what}()`"))?; |
| 4014 | // `and_then`'s closure already returns the wrapped type; `map`'s does |
| 4015 | // not and has to be re-wrapped. |
| 4016 | let (test, some_branch, none_branch, out_ty) = if is_opt { |
| 4017 | let out = if what == "map" { |
| 4018 | Nim::Named("Option".into(), vec![inner.clone()]) |
| 4019 | } else { |
| 4020 | inner.clone() |
| 4021 | }; |
| 4022 | let body_code = if what == "map" { |
| 4023 | format!("rsSome[{}]({})", inner.render(), v.code) |
| 4024 | } else { |
| 4025 | v.code.clone() |
| 4026 | }; |
| 4027 | ( |
| 4028 | format!("{}.has", tmp), |
| 4029 | body_code, |
| 4030 | format!("rsNone[{}]()", elem_arg(&out).render()), |
| 4031 | out, |
| 4032 | ) |
| 4033 | } else { |
| 4034 | let e = targs[1].clone(); |
| 4035 | let out = if what == "map" { |
| 4036 | Nim::Named("Result".into(), vec![inner.clone(), e.clone()]) |
| 4037 | } else { |
| 4038 | inner.clone() |
| 4039 | }; |
| 4040 | let ok_ty = elem_arg(&out); |
| 4041 | let body_code = if what == "map" { |
| 4042 | format!("rsOk[{}, {}]({})", inner.render(), e.render(), v.code) |
| 4043 | } else { |
| 4044 | v.code.clone() |
| 4045 | }; |
| 4046 | ( |
| 4047 | format!("{}.ok", tmp), |
| 4048 | body_code, |
| 4049 | format!("rsErr[{}, {}]({}.err)", ok_ty.render(), e.render(), tmp), |
| 4050 | out, |
| 4051 | ) |
| 4052 | }; |
| 4053 | Ok(Val::new( |
| 4054 | format!("(if {}: {} else: {})", test, some_branch, none_branch), |
| 4055 | Some(out_ty), |
| 4056 | )) |
| 4057 | } |
| 4058 | |
| 4059 | /// `|x| x + 1` -> a Nim anonymous proc. |
| 4060 | /// |
| 4061 | /// Nim's closures capture by reference, as Rust's non-`move` closures do. |
| 4062 | /// A `move` closure captures by value, which is a different thing, so it |
| 4063 | /// is rejected rather than lowered to the same construct. |
| 4064 | fn closure(&mut self, c: &syn::ExprClosure, expect: Option<&Nim>) -> Result<Val, String> { |
| 4065 | if c.capture.is_some() { |
| 4066 | return Err("a `move` closure captures by value; Nim's closures \ |
| 4067 | capture by reference, and the two are not the same" |
| 4068 | .into()); |
| 4069 | } |
| 4070 | let want: Option<&Vec<Nim>> = match expect { |
| 4071 | Some(Nim::Proc(a, _)) => Some(a), |
| 4072 | _ => None, |
| 4073 | }; |
| 4074 | |
| 4075 | self.push_scope(); |
| 4076 | let mut parts = Vec::new(); |
| 4077 | let mut ptys = Vec::new(); |
| 4078 | for (i, p) in c.inputs.iter().enumerate() { |
| 4079 | let (name, ann) = match p { |
| 4080 | Pat::Ident(id) => (id.ident.to_string(), None), |
| 4081 | Pat::Type(t) => match &*t.pat { |
| 4082 | Pat::Ident(id) => (id.ident.to_string(), Some(self.map_ty(&t.ty)?)), |
| 4083 | _ => return Err("only plain identifier closure parameters are supported".into()), |
| 4084 | }, |
| 4085 | Pat::Wild(_) => (format!("unused{i}"), None), |
| 4086 | _ => return Err("only plain identifier closure parameters are supported".into()), |
| 4087 | }; |
| 4088 | let t = ann |
| 4089 | .or_else(|| want.and_then(|w| w.get(i).cloned())) |
| 4090 | .ok_or_else(|| { |
| 4091 | format!( |
| 4092 | "cannot infer the type of closure parameter `{name}`; \ |
| 4093 | annotate it" |
| 4094 | ) |
| 4095 | })?; |
| 4096 | parts.push(format!("{}: {}", ident(&name), t.render())); |
| 4097 | self.bind(&name, t.clone()); |
| 4098 | ptys.push(t); |
| 4099 | } |
| 4100 | |
| 4101 | let ret_ann = match &c.output { |
| 4102 | ReturnType::Default => None, |
| 4103 | ReturnType::Type(_, t) => Some(self.map_ty(t)?.owned()), |
| 4104 | }; |
| 4105 | let body = match &*c.body { |
| 4106 | Expr::Block(b) => single_expr(&b.block) |
| 4107 | .ok_or("a closure body with statements is not implemented yet")?, |
| 4108 | other => other, |
| 4109 | }; |
| 4110 | let v = self.expr_at(body, ret_ann.as_ref())?; |
| 4111 | self.pop_scope(); |
| 4112 | |
| 4113 | let ret = ret_ann |
| 4114 | .or_else(|| v.ty.clone()) |
| 4115 | .ok_or("cannot infer a closure's return type; annotate it")?; |
| 4116 | Ok(Val::new( |
| 4117 | format!("(proc ({}): {} = {})", parts.join(", "), ret.render(), v.code), |
| 4118 | Some(Nim::Proc(ptys, Box::new(ret))), |
| 4119 | )) |
| 4120 | } |
| 4121 | |
| 4122 | /// Lower a block's statements at the current indentation, without opening |
| 4123 | /// a Nim `block:` -- used for `unsafe { .. }`, which introduces no scope |
| 4124 | /// of its own in the generated code. |
| 4125 | fn nested_block_flat(&mut self, b: &syn::Block) -> Result<(), String> { |
| 4126 | self.push_scope(); |
| 4127 | let tail = self.block_body(b)?; |
| 4128 | self.emit_tail(tail); |
| 4129 | self.pop_scope(); |
| 4130 | Ok(()) |
| 4131 | } |
| 4132 | |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 4133 | fn try_op(&mut self, t: &syn::ExprTry) -> Result<Val, String> { |
| 4134 | if self.in_loop_cond { |
| 4135 | return Err("`?` in a loop condition is not implemented yet: the \ |
| 4136 | early-return it expands to would be evaluated once, \ |
| 4137 | before the loop, rather than on each iteration" |
| 4138 | .into()); |
| 4139 | } |
| 4140 | let v = self.expr(&t.expr)?; |
| Add display.rs and the alloc half: all of base16ct now goes through afb2a6e nandithebull 9h ago | 4141 | if self.fmt_param.is_some() { |
| 4142 | // Writing into a string cannot fail, so `?` on a formatter write |
| 4143 | // is a no-op. `?` on anything else can fail, and `format!` panics |
| 4144 | // when a formatting impl returns an error -- so that is what the |
| 4145 | // error branch does here, with std's own message. |
| 4146 | if v.ty.as_ref() == Some(&Nim::Unit) { |
| 4147 | return Ok(v); |
| 4148 | } |
| 4149 | if let Some(Nim::Named(n, a)) = v.ty.clone() { |
| 4150 | if n == "Result" && a.len() == 2 { |
| 4151 | let tmp = self.fresh("Fmt"); |
| 4152 | self.line(&format!( |
| 4153 | "let {}: {} = {}", |
| 4154 | tmp, |
| 4155 | Nim::Named(n, a.clone()).render(), |
| 4156 | v.code |
| 4157 | )); |
| 4158 | self.line(&format!("if not {}.ok:", tmp)); |
| 4159 | self.line( |
| 4160 | " rsPanic(\"a formatting trait implementation returned an error\")", |
| 4161 | ); |
| 4162 | return Ok(Val::new(format!("{}.val", tmp), Some(a[0].clone()))); |
| 4163 | } |
| 4164 | } |
| 4165 | } |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 4166 | if let (Some(guard), Some(w)) = (v.guard.clone(), v.window.clone()) { |
| 4167 | // An `Option`/`Result` of a view: the check is emitted here and the |
| 4168 | // view itself survives as an alias, since it has no value form. |
| 4169 | let ret = self.ret.clone().ok_or("`?` outside a function with a return type")?; |
| 4170 | let err = v.guard_err.clone().ok_or( |
| 4171 | "`?` on a `get`/`get_mut` needs an `ok_or` to say what the error is", |
| 4172 | )?; |
| 4173 | let Nim::Named(n, ra) = &ret else { |
| 4174 | return Err(format!("`?` in a function returning `{}`", ret.render())); |
| 4175 | }; |
| 4176 | if n != "Result" || ra.len() != 2 { |
| 4177 | return Err(format!("`?` in a function returning `{}`", ret.render())); |
| 4178 | } |
| 4179 | self.line(&format!("if not {}:", guard)); |
| 4180 | self.line(&format!( |
| 4181 | " return rsErr[{}, {}]({})", |
| 4182 | ra[0].render(), |
| 4183 | ra[1].render(), |
| 4184 | err |
| 4185 | )); |
| 4186 | let mut out = Val::new(String::new(), None); |
| 4187 | out.window = Some(w); |
| 4188 | return Ok(out); |
| 4189 | } |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 4190 | let vt = v.ty.clone().ok_or( |
| 4191 | "`?` needs a known `Result`/`Option` type; annotate the expression it applies to", |
| 4192 | )?; |
| 4193 | let ret = self |
| 4194 | .ret |
| 4195 | .clone() |
| 4196 | .ok_or("`?` outside a function with a return type")?; |
| 4197 | let tmp = self.fresh("Try"); |
| 4198 | self.line(&format!("let {}: {} = {}", tmp, vt.render(), v.code)); |
| 4199 | |
| 4200 | match (&vt, &ret) { |
| 4201 | (Nim::Named(a, ai), Nim::Named(b, bi)) |
| 4202 | if a == "Result" && b == "Result" && ai.len() == 2 && bi.len() == 2 => |
| 4203 | { |
| Add closures and unsafe; base16ct's lower.rs and upper.rs go through 0a375d8 nandithebull 9h ago | 4204 | // Rust inserts a `From::from` on the error here. Where the |
| 4205 | // types differ we call the crate's own `impl From`; we never |
| 4206 | // assume the conversion is the identity. |
| 4207 | let err = if ai[1] == bi[1] { |
| 4208 | format!("{}.err", tmp) |
| 4209 | } else { |
| 4210 | let key = (type_name(&ai[1]), type_name(&bi[1])); |
| 4211 | let f = self.from_impls.get(&key).cloned().ok_or_else(|| { |
| 4212 | format!( |
| 4213 | "`?` needs `From<{}> for {}` to convert the error, and \ |
| 4214 | no such `impl` is in scope; assuming the conversion is \ |
| 4215 | the identity would be a guess", |
| 4216 | key.0, key.1 |
| 4217 | ) |
| 4218 | })?; |
| 4219 | format!("{}({}.err)", f, tmp) |
| 4220 | }; |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 4221 | self.line(&format!("if not {}.ok:", tmp)); |
| 4222 | self.line(&format!( |
| Add closures and unsafe; base16ct's lower.rs and upper.rs go through 0a375d8 nandithebull 9h ago | 4223 | " return rsErr[{}, {}]({})", |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 4224 | bi[0].render(), |
| 4225 | bi[1].render(), |
| Add closures and unsafe; base16ct's lower.rs and upper.rs go through 0a375d8 nandithebull 9h ago | 4226 | err |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 4227 | )); |
| 4228 | Ok(Val::new(format!("{}.val", tmp), Some(ai[0].clone()))) |
| 4229 | } |
| 4230 | (Nim::Named(a, ai), Nim::Named(b, bi)) |
| 4231 | if a == "Option" && b == "Option" && ai.len() == 1 && bi.len() == 1 => |
| 4232 | { |
| 4233 | self.line(&format!("if not {}.has:", tmp)); |
| 4234 | self.line(&format!(" return rsNone[{}]()", bi[0].render())); |
| 4235 | Ok(Val::new(format!("{}.val", tmp), Some(ai[0].clone()))) |
| 4236 | } |
| 4237 | _ => Err(format!( |
| 4238 | "`?` on `{}` in a function returning `{}` is not a supported \ |
| 4239 | combination", |
| 4240 | vt.render(), |
| 4241 | ret.render() |
| 4242 | )), |
| 4243 | } |
| 4244 | } |
| 4245 | |
| 4246 | fn call(&mut self, c: &syn::ExprCall, expect: Option<&Nim>) -> Result<Val, String> { |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 4247 | let Expr::Path(p) = &*c.func else { |
| 4248 | return Err("only calls to named functions are supported".into()); |
| 4249 | }; |
| 4250 | let name = path_name(&p.path); |
| Add closures and unsafe; base16ct's lower.rs and upper.rs go through 0a375d8 nandithebull 9h ago | 4251 | let target = self.resolve_fn(&p.path); |
| 4252 | let ptys: Vec<Nim> = target |
| 4253 | .as_ref() |
| 4254 | .and_then(|k| self.fns.get(k)) |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 4255 | .map(|s| s.params.clone()) |
| 4256 | .unwrap_or_default(); |
| 4257 | let mut args = Vec::new(); |
| 4258 | for (i, a) in c.args.iter().enumerate() { |
| 4259 | let want = ptys.get(i).cloned(); |
| 4260 | args.push(self.expr_at(a, want.as_ref())?); |
| 4261 | } |
| 4262 | let codes: Vec<String> = args.iter().map(|a| a.code.clone()).collect(); |
| 4263 | |
| 4264 | // Constructors from the prelude. |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 4265 | // `Ok`/`Err` must name the *whole* Result type, not just the half |
| 4266 | // being constructed: Nim cannot infer `E` from an `Ok(v)` alone. |
| 4267 | match name.as_str() { |
| 4268 | "Some" => { |
| 4269 | let inner = match expect { |
| 4270 | Some(Nim::Named(n, a)) if n == "Option" && a.len() == 1 => a[0].render(), |
| 4271 | _ => { |
| 4272 | return Err("`Some(..)` needs a known `Option<T>` type here; \ |
| 4273 | annotate the binding or the return type" |
| 4274 | .into()) |
| 4275 | } |
| 4276 | }; |
| 4277 | return Ok(Val::new( |
| 4278 | format!("rsSome[{}]({})", inner, codes.join(", ")), |
| 4279 | expect.cloned(), |
| 4280 | )); |
| 4281 | } |
| Add display.rs and the alloc half: all of base16ct now goes through afb2a6e nandithebull 9h ago | 4282 | "Ok" if self.fmt_param.is_some() |
| 4283 | && matches!(c.args.first(), Some(Expr::Tuple(t)) if t.elems.is_empty()) => |
| 4284 | { |
| 4285 | // `Ok(())` ends a `fmt` body: nothing more is written. |
| 4286 | return Ok(Val::new(String::new(), Some(Nim::Unit))); |
| 4287 | } |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 4288 | "Ok" | "Err" => { |
| 4289 | let (t, e) = match expect { |
| 4290 | Some(Nim::Named(n, a)) if n == "Result" && a.len() == 2 => { |
| 4291 | (a[0].render(), a[1].render()) |
| 4292 | } |
| 4293 | _ => { |
| 4294 | return Err(format!( |
| 4295 | "`{name}(..)` needs a known `Result<T, E>` type here; \ |
| 4296 | annotate the binding or the return type" |
| 4297 | )) |
| 4298 | } |
| 4299 | }; |
| 4300 | let ctor = if name == "Ok" { "rsOk" } else { "rsErr" }; |
| 4301 | let arg = if codes.is_empty() { String::new() } else { codes.join(", ") }; |
| 4302 | return Ok(Val::new( |
| 4303 | format!("{}[{}, {}]({})", ctor, t, e, arg), |
| 4304 | expect.cloned(), |
| 4305 | )); |
| 4306 | } |
| 4307 | _ => {} |
| 4308 | } |
| 4309 | |
| Add display.rs and the alloc half: all of base16ct now goes through afb2a6e nandithebull 9h ago | 4310 | // A tuple struct applied to arguments: `HexDisplay(bytes)`. Nim's |
| 4311 | // object constructor names its fields even when Rust's does not. |
| 4312 | if let Some(fields) = self.structs.get(&name).cloned() { |
| 4313 | if fields.len() == c.args.len() { |
| 4314 | let mut parts = Vec::new(); |
| 4315 | for (i, a) in c.args.iter().enumerate() { |
| 4316 | let v = self.expr_at(a, Some(&fields[i].1))?; |
| 4317 | parts.push(format!("{}: {}", ident(&fields[i].0), v.code)); |
| 4318 | } |
| 4319 | return Ok(Val::new( |
| 4320 | format!("{}({})", ident(&name), parts.join(", ")), |
| 4321 | Some(Nim::Named(name.clone(), vec![])), |
| 4322 | )); |
| 4323 | } |
| 4324 | } |
| 4325 | |
| Lower the `log` facade, and add explicit enum discriminants 12c0a01 nandithebull 6h ago | 4326 | // `log::set_max_level` / `log::max_level`. |
| 4327 | if name == "set_max_level" && codes.len() == 1 { |
| 4328 | return Ok(Val::new( |
| 4329 | format!("rsLogMaxLevel = int({})", codes[0]), |
| 4330 | Some(Nim::Unit), |
| 4331 | )); |
| 4332 | } |
| 4333 | if name == "max_level" && codes.is_empty() { |
| 4334 | return Ok(Val::new( |
| 4335 | "RsLogFilter(rsLogMaxLevel)", |
| 4336 | Some(Nim::Prim("RsLogFilter".into())), |
| 4337 | )); |
| 4338 | } |
| 4339 | |
| Add generics; transpile the part of cosmic-theme that is reachable ff34e1b nandithebull 7h ago | 4340 | // `Spacing::from(d)`: a `From` impl called through its target type. |
| 4341 | // Rust picks the impl by the argument's type, and so do we -- Nim |
| 4342 | // cannot overload on return type, so each impl has its own proc name. |
| 4343 | if name == "from" && codes.len() == 1 { |
| 4344 | if let Some(q) = p.path.segments.iter().rev().nth(1).map(|s| s.ident.to_string()) { |
| 4345 | let q = if q == "Self" { |
| 4346 | self.self_ty.as_ref().map(type_name).unwrap_or(q) |
| 4347 | } else { |
| 4348 | q |
| 4349 | }; |
| 4350 | if let Some(src) = args[0].ty.as_ref().map(type_name) { |
| 4351 | if let Some(f) = self.from_impls.get(&(src, q.clone())).cloned() { |
| 4352 | return Ok(Val::new( |
| 4353 | format!("{}({})", f, codes[0]), |
| 4354 | Some(Nim::Named(q, vec![])), |
| 4355 | )); |
| 4356 | } |
| 4357 | } |
| 4358 | } |
| 4359 | } |
| 4360 | |
| Transpile a second crate, adler2, to test whether any of this generalises 5fdd5be nandithebull 8h ago | 4361 | // `u32::from(b)`: `From` between primitives is lossless by definition |
| 4362 | // -- it is the widening direction only -- so a plain Nim conversion is |
| 4363 | // exact. (The truncating direction is `as`, which is `cast`.) |
| 4364 | if name == "from" && codes.len() == 1 { |
| 4365 | if let Some(q) = p.path.segments.iter().rev().nth(1) { |
| 4366 | if let Some(Nim::Prim(t)) = ty::prim(&q.ident.to_string()) { |
| 4367 | return Ok(Val::new( |
| 4368 | format!("{}({})", t, codes[0]), |
| 4369 | Some(Nim::Prim(t)), |
| 4370 | )); |
| 4371 | } |
| 4372 | } |
| 4373 | } |
| 4374 | |
| Add closures and unsafe; base16ct's lower.rs and upper.rs go through 0a375d8 nandithebull 9h ago | 4375 | // `core::str::from_utf8_unchecked(b)` reinterprets a byte view as a |
| 4376 | // string view; no copy, no validation, same memory. |
| 4377 | if name == "from_utf8_unchecked" && codes.len() == 1 { |
| Add display.rs and the alloc half: all of base16ct now goes through afb2a6e nandithebull 9h ago | 4378 | // `String::from_utf8_unchecked(v)` takes ownership and yields an |
| 4379 | // owned `String`; `str::from_utf8_unchecked(b)` borrows and yields |
| 4380 | // a view. Same name, different operations -- the qualifier says |
| 4381 | // which, and an unqualified call is ambiguous. |
| 4382 | let q = p |
| 4383 | .path |
| 4384 | .segments |
| 4385 | .iter() |
| 4386 | .rev() |
| 4387 | .nth(1) |
| 4388 | .map(|s| s.ident.to_string()); |
| 4389 | return match q.as_deref() { |
| 4390 | Some("String") => Ok(Val::new( |
| 4391 | format!("rsStringOf({})", codes[0]), |
| 4392 | Some(Nim::Prim("string".into())), |
| 4393 | )), |
| 4394 | Some("str") => Ok(Val::new( |
| 4395 | format!("rsStrView({})", codes[0]), |
| 4396 | Some(Nim::OpenArray(Box::new(Nim::Prim("char".into())))), |
| 4397 | )), |
| 4398 | _ => Err( |
| 4399 | "`from_utf8_unchecked` must be written as `str::..` (a \ |
| 4400 | borrowed view) or `String::..` (an owned string); the two \ |
| 4401 | are different operations" |
| 4402 | .into(), |
| 4403 | ), |
| 4404 | }; |
| Add closures and unsafe; base16ct's lower.rs and upper.rs go through 0a375d8 nandithebull 9h ago | 4405 | } |
| 4406 | |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 4407 | // A tuple enum variant applied to arguments: `Shape::Circle(1.0)`. |
| 4408 | if let Some((def, v)) = self.resolve_variant(&p.path) { |
| Add generics; transpile the part of cosmic-theme that is reachable ff34e1b nandithebull 7h ago | 4409 | let (ty, _) = self.variant_type(&def, expect)?; |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 4410 | return Ok(Val::new( |
| 4411 | format!("{}({})", def.ctor_ident(&v), codes.join(", ")), |
| Add generics; transpile the part of cosmic-theme that is reachable ff34e1b nandithebull 7h ago | 4412 | Some(ty), |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 4413 | )); |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 4414 | } |
| 4415 | |
| 4416 | // A bare path that names a primitive type is Rust's tuple-struct-like |
| 4417 | // conversion, e.g. `String::from(..)`; handled by the method path. |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 4418 | // Calling a proc-typed local, which is how an `impl Fn(..)` parameter |
| 4419 | // is invoked. |
| 4420 | if let Some(Nim::Proc(_, ret)) = self.lookup(&name) { |
| 4421 | return Ok(Val::new( |
| 4422 | format!("{}({})", ident(&name), codes.join(", ")), |
| 4423 | Some((*ret).clone()), |
| 4424 | )); |
| 4425 | } |
| Transpile a second crate, adler2, to test whether any of this generalises 5fdd5be nandithebull 8h ago | 4426 | // `Adler32::new()` / `Adler32::default()`: a method called through |
| 4427 | // its type rather than through a receiver. |
| 4428 | if let Some(q) = p.path.segments.iter().rev().nth(1).map(|s| s.ident.to_string()) { |
| 4429 | // `Self::new()` inside an `impl` names the type being implemented. |
| 4430 | let q = if q == "Self" { |
| 4431 | self.self_ty.as_ref().map(type_name).unwrap_or(q) |
| 4432 | } else { |
| 4433 | q |
| 4434 | }; |
| 4435 | if let Some(sig) = self.methods.get(&(q.clone(), name.clone())) { |
| Lower `bitflags!` directly, checked against the real crate af6e50f nandithebull 7h ago | 4436 | // Re-lower the arguments with the declared parameter types, so |
| 4437 | // a literal takes the width the signature asks for. |
| 4438 | let declared = sig.params.clone(); |
| 4439 | let mut args = args.clone(); |
| 4440 | let mut codes = codes.clone(); |
| 4441 | for (i, a) in c.args.iter().enumerate() { |
| 4442 | if let Some(want) = declared.get(i) { |
| 4443 | let want = want.clone().unvar(); |
| 4444 | args[i] = self.expr_at(a, Some(&want))?; |
| 4445 | codes[i] = args[i].code.clone(); |
| 4446 | } |
| 4447 | } |
| 4448 | let sig = &self.methods[&(q.clone(), name.clone())]; |
| Add generics; transpile the part of cosmic-theme that is reachable ff34e1b nandithebull 7h ago | 4449 | let arg_tys: Vec<Option<Nim>> = args.iter().map(|a| a.ty.clone()).collect(); |
| 4450 | let ret = Self::instantiate(sig, &arg_tys); |
| Transpile a second crate, adler2, to test whether any of this generalises 5fdd5be nandithebull 8h ago | 4451 | let nim = self |
| 4452 | .statics |
| 4453 | .get(&(q.clone(), name.clone())) |
| 4454 | .cloned() |
| 4455 | .unwrap_or_else(|| ident(&name)); |
| 4456 | return Ok(Val::new(format!("{}({})", nim, codes.join(", ")), Some(ret))); |
| 4457 | } |
| 4458 | } |
| Add generics; transpile the part of cosmic-theme that is reachable ff34e1b nandithebull 7h ago | 4459 | let arg_tys: Vec<Option<Nim>> = args.iter().map(|a| a.ty.clone()).collect(); |
| 4460 | let ret = target |
| 4461 | .as_ref() |
| 4462 | .and_then(|k| self.fns.get(k)) |
| 4463 | .map(|sig| Self::instantiate(sig, &arg_tys)); |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 4464 | if ret.is_none() && !self.structs.contains_key(&name) && !self.enums.contains_key(&name) { |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 4465 | return Err(format!( |
| 4466 | "call to unknown function `{name}`; only functions defined in \ |
| 4467 | this file and the supported standard-library subset can be lowered" |
| 4468 | )); |
| 4469 | } |
| Add closures and unsafe; base16ct's lower.rs and upper.rs go through 0a375d8 nandithebull 9h ago | 4470 | let nim = match &target { |
| 4471 | Some((m, n)) => self.fn_name(m, n), |
| 4472 | None => ident(&name), |
| 4473 | }; |
| 4474 | Ok(Val::new(format!("{}({})", nim, codes.join(", ")), ret)) |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 4475 | } |
| 4476 | |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 4477 | fn method(&mut self, m: &syn::ExprMethodCall, expect: Option<&Nim>) -> Result<Val, String> { |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 4478 | let name = m.method.to_string(); |
| Transpile a second crate, adler2, to test whether any of this generalises 5fdd5be nandithebull 8h ago | 4479 | // `chunk_iter.remainder()` — the tail `chunks_exact` will not yield. |
| 4480 | if name == "remainder" && m.args.is_empty() { |
| 4481 | if let Expr::Path(p) = &*m.receiver { |
| 4482 | if let Some(Alias::Iterator(it)) = self.lookup_alias(&path_name(&p.path)) { |
| 4483 | if let Iter::Chunks { code, base, len, k, elem, .. } = &*it { |
| 4484 | let kept = format!("(({} div int({})) * int({}))", len, k, k); |
| 4485 | let mut v = Val::new( |
| 4486 | String::new(), |
| 4487 | elem.clone().map(|e| Nim::OpenArray(Box::new(e))), |
| 4488 | ); |
| 4489 | v.window = Some(Alias::Window { |
| 4490 | code: code.clone(), |
| 4491 | off: format!("({} + {})", base, kept), |
| 4492 | len: format!("({} - {})", len, kept), |
| 4493 | elem: elem.clone(), |
| 4494 | }); |
| 4495 | return Ok(v); |
| 4496 | } |
| 4497 | return Err( |
| 4498 | "`.remainder()` is only defined for a `chunks_exact` iterator".into(), |
| 4499 | ); |
| 4500 | } |
| 4501 | } |
| 4502 | return Err("`.remainder()` needs an iterator bound by `let`".into()); |
| 4503 | } |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 4504 | if let Some(Alias::Window { len, .. }) = self.window_of(&m.receiver) { |
| 4505 | match name.as_str() { |
| 4506 | "len" => { |
| 4507 | return Ok(Val::new(format!("uint({})", len), Some(Nim::Prim("uint".into())))) |
| 4508 | } |
| 4509 | "is_empty" => { |
| 4510 | return Ok(Val::new(format!("({} == 0)", len), Some(Nim::Prim("bool".into())))) |
| 4511 | } |
| 4512 | other => { |
| 4513 | return Err(format!( |
| 4514 | "`.{other}()` on a slice window from `chunks_exact`/\ |
| 4515 | `windows` is not implemented; only indexing and \ |
| 4516 | `len()` are" |
| 4517 | )) |
| 4518 | } |
| 4519 | } |
| 4520 | } |
| 4521 | let recv = self.expr(&m.receiver)?; |
| 4522 | let rt0 = recv.ty.clone(); |
| 4523 | |
| 4524 | // `s.get(a..b)` / `s.get_mut(a..b)`: an `Option<&[T]>`. Nim has no |
| 4525 | // way to put a view in an object, so instead of materialising an |
| 4526 | // Option the view and its validity condition travel together until |
| 4527 | // an `ok_or`/`?`/`unwrap` resolves them. |
| 4528 | if matches!(name.as_str(), "get" | "get_mut") |
| 4529 | && matches!(m.args.first(), Some(Expr::Range(_))) |
| 4530 | { |
| 4531 | let Some(Expr::Range(r)) = m.args.first() else { unreachable!() }; |
| Add closures and unsafe; base16ct's lower.rs and upper.rs go through 0a375d8 nandithebull 9h ago | 4532 | let (code, base, blen, belem) = self.slice_parts(&m.receiver)?; |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 4533 | let lo = match &r.start { |
| 4534 | Some(e) => format!("int({})", self.expr(e)?.code), |
| 4535 | None => "0".into(), |
| 4536 | }; |
| 4537 | let len = match (&r.end, r.limits) { |
| 4538 | (Some(e), syn::RangeLimits::HalfOpen(_)) => { |
| 4539 | format!("(int({}) - {})", self.expr(e)?.code, lo) |
| 4540 | } |
| 4541 | (Some(e), syn::RangeLimits::Closed(_)) => { |
| 4542 | format!("(int({}) - {} + 1)", self.expr(e)?.code, lo) |
| 4543 | } |
| Add closures and unsafe; base16ct's lower.rs and upper.rs go through 0a375d8 nandithebull 9h ago | 4544 | (None, _) => format!("({} - {})", blen, lo), |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 4545 | }; |
| Add closures and unsafe; base16ct's lower.rs and upper.rs go through 0a375d8 nandithebull 9h ago | 4546 | // Hoisted, so the bounds are computed once -- as Rust computes |
| 4547 | // them once -- and cannot be re-evaluated later in a scope where |
| 4548 | // the names they mention have been shadowed by a loop pattern. |
| 4549 | let off_t = self.fresh("Off"); |
| 4550 | let len_t = self.fresh("Len"); |
| 4551 | self.line(&format!("let {}: int = {} + {}", off_t, base, lo)); |
| 4552 | self.line(&format!("let {}: int = {}", len_t, len)); |
| 4553 | let elem = belem |
| 4554 | .or_else(|| elem_of(&rt0)) |
| 4555 | .ok_or("cannot infer the element type of this slice")?; |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 4556 | let mut v = Val::new( |
| 4557 | String::new(), |
| 4558 | Some(Nim::Named( |
| 4559 | "Option".into(), |
| 4560 | vec![Nim::OpenArray(Box::new(elem.clone()))], |
| 4561 | )), |
| 4562 | ); |
| Add closures and unsafe; base16ct's lower.rs and upper.rs go through 0a375d8 nandithebull 9h ago | 4563 | v.guard = Some(format!("({} + {} <= {})", off_t, len_t, blen)); |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 4564 | v.window = Some(Alias::Window { |
| Add closures and unsafe; base16ct's lower.rs and upper.rs go through 0a375d8 nandithebull 9h ago | 4565 | code, |
| 4566 | off: off_t, |
| 4567 | len: len_t, |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 4568 | elem: Some(elem), |
| 4569 | }); |
| 4570 | return Ok(v); |
| 4571 | } |
| 4572 | |
| Add closures and unsafe; base16ct's lower.rs and upper.rs go through 0a375d8 nandithebull 9h ago | 4573 | // `.map`/`.and_then` over an `Option`/`Result` take a closure whose |
| 4574 | // parameter type comes from the receiver, so they are handled before |
| 4575 | // the arguments are lowered. The closure is expanded inline, with its |
| 4576 | // parameter aliased to the payload: that keeps the whole thing an |
| 4577 | // expression and avoids handing a view to a generic proc. |
| 4578 | if matches!(name.as_str(), "map" | "and_then") && m.args.len() == 1 { |
| 4579 | if let (Some(Nim::Named(kind, targs)), Expr::Closure(c)) = |
| 4580 | (recv.ty.clone(), &m.args[0]) |
| 4581 | { |
| 4582 | if (kind == "Option" && targs.len() == 1) || (kind == "Result" && targs.len() == 2) |
| 4583 | { |
| 4584 | return self.map_closure(&name, &recv, &kind, &targs, c); |
| 4585 | } |
| 4586 | } |
| 4587 | } |
| 4588 | |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 4589 | // `x.wrapping_add(1)` and `x.min(3)` take an argument of the receiver's |
| 4590 | // own type; `v.push(e)` takes the element type. |
| 4591 | let arg_want = match (name.as_str(), &recv.ty) { |
| 4592 | ("push", Some(Nim::Seq(t))) | ("push", Some(Nim::OpenArray(t))) => Some((**t).clone()), |
| 4593 | (_, t) => t.clone(), |
| 4594 | }; |
| 4595 | let mut args = Vec::new(); |
| 4596 | for a in &m.args { |
| 4597 | args.push(self.expr_at(a, arg_want.as_ref())?); |
| 4598 | } |
| 4599 | let a0 = args.first().map(|a| a.code.clone()); |
| 4600 | let rt = recv.ty.clone(); |
| 4601 | |
| Lower `bitflags!` directly, checked against the real crate af6e50f nandithebull 7h ago | 4602 | // A method the input defines wins over our model of the standard |
| 4603 | // library: `is_empty` on a `bitflags!` type is that type's, not the |
| 4604 | // sequence one. Rust resolves inherent methods the same way. |
| 4605 | if let Some(t) = &rt { |
| 4606 | let key = (type_name(t), name.clone()); |
| 4607 | if self.methods.contains_key(&key) { |
| 4608 | let declared = self.methods[&key].params.clone(); |
| 4609 | let skip = usize::from(declared.len() == m.args.len() + 1); |
| 4610 | for (i, a) in m.args.iter().enumerate() { |
| 4611 | if let Some(want) = declared.get(i + skip) { |
| 4612 | let want = want.clone().unvar(); |
| 4613 | args[i] = self.expr_at(a, Some(&want))?; |
| 4614 | } |
| 4615 | } |
| 4616 | let mut arg_tys: Vec<Option<Nim>> = vec![rt.clone()]; |
| 4617 | arg_tys.extend(args.iter().map(|a| a.ty.clone())); |
| 4618 | let ret = Self::instantiate(&self.methods[&key], &arg_tys); |
| 4619 | let nim = self |
| 4620 | .statics |
| 4621 | .get(&key) |
| 4622 | .cloned() |
| 4623 | .unwrap_or_else(|| ident(&name)); |
| 4624 | let mut all = vec![recv.code.clone()]; |
| 4625 | all.extend(args.iter().map(|a| a.code.clone())); |
| 4626 | return Ok(Val::new(format!("{}({})", nim, all.join(", ")), Some(ret))); |
| 4627 | } |
| 4628 | } |
| 4629 | |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 4630 | let (code, ty) = match name.as_str() { |
| 4631 | // Rust's `len()` is `usize`; Nim's is `int`. The conversion is |
| 4632 | // explicit so that a `usize` binding type-checks on the Nim side. |
| 4633 | "len" => (format!("uint({}.len)", recv.code), Some(Nim::Prim("uint".into()))), |
| 4634 | "is_empty" => (format!("({}.len == 0)", recv.code), Some(Nim::Prim("bool".into()))), |
| 4635 | "push" => (format!("{}.add({})", recv.code, a0.unwrap_or_default()), Some(Nim::Unit)), |
| 4636 | "clone" | "to_vec" | "to_owned" | "as_slice" | "as_ref" | "as_mut" | "iter" |
| 4637 | | "into_iter" => (recv.code.clone(), rt.clone()), |
| 4638 | "unwrap" | "expect" => { |
| Add display.rs and the alloc half: all of base16ct now goes through afb2a6e nandithebull 9h ago | 4639 | // Expanded inline rather than called as a generic proc: when |
| 4640 | // the payload is a view, Nim can only borrow from a path |
| 4641 | // expression, which a proc body containing the panic is not. |
| 4642 | let (kind, inner) = match &rt { |
| 4643 | Some(Nim::Named(n, a)) if n == "Option" && a.len() == 1 => { |
| 4644 | ("Option", a[0].clone()) |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 4645 | } |
| Add display.rs and the alloc half: all of base16ct now goes through afb2a6e nandithebull 9h ago | 4646 | Some(Nim::Named(n, a)) if n == "Result" && a.len() == 2 => { |
| 4647 | ("Result", a[0].clone()) |
| 4648 | } |
| 4649 | _ => { |
| 4650 | return Err(format!( |
| 4651 | "`.{name}()` needs a known `Option`/`Result` receiver type" |
| 4652 | )) |
| 4653 | } |
| 4654 | }; |
| 4655 | if self.in_loop_cond { |
| 4656 | return Err(format!( |
| 4657 | "`.{name}()` in a loop condition is not implemented yet: the \ |
| 4658 | check it expands to would run once, before the loop" |
| 4659 | )); |
| 4660 | } |
| 4661 | let tmp = self.fresh("Unwrap"); |
| 4662 | let rty = rt.clone().unwrap(); |
| 4663 | self.line(&format!("let {}: {} = {}", tmp, rty.render(), recv.code)); |
| 4664 | let (test, msg) = if kind == "Option" { |
| 4665 | (format!("{}.has", tmp), "called `Option::unwrap()` on a `None` value") |
| 4666 | } else { |
| 4667 | (format!("{}.ok", tmp), "called `Result::unwrap()` on an `Err` value") |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 4668 | }; |
| Add display.rs and the alloc half: all of base16ct now goes through afb2a6e nandithebull 9h ago | 4669 | let msg = if name == "expect" { |
| 4670 | args.first().map(|a| a.code.clone()).unwrap_or_else(|| fmt::nim_str(msg)) |
| 4671 | } else { |
| 4672 | fmt::nim_str(msg) |
| 4673 | }; |
| 4674 | self.line(&format!("if not {}:", test)); |
| 4675 | self.line(&format!(" rsPanic({})", msg)); |
| 4676 | // If the payload is a view, hand back an alias rather than a |
| 4677 | // value: Nim will not let a `let` borrow out of a local, and a |
| 4678 | // view is a reference anyway, so there is nothing to bind. |
| 4679 | // `{tmp}.val` is a plain field access, so substituting it at |
| 4680 | // each use re-evaluates nothing. |
| 4681 | if matches!(inner, Nim::OpenArray(_)) { |
| 4682 | let mut v = Val::new(format!("{}.val", tmp), Some(inner.clone())); |
| 4683 | v.window = Some(Alias::Value { |
| 4684 | code: format!("{}.val", tmp), |
| 4685 | ty: Some(inner), |
| 4686 | }); |
| 4687 | return Ok(v); |
| 4688 | } |
| 4689 | (format!("{}.val", tmp), Some(inner)) |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 4690 | } |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 4691 | "ok_or" if recv.guard.is_some() => { |
| 4692 | let e = args.first().ok_or("`ok_or` takes one argument")?; |
| 4693 | let ety = e.ty.clone(); |
| 4694 | let mut v = recv.clone(); |
| 4695 | v.guard_err = Some(e.code.clone()); |
| 4696 | v.ty = match (&recv.ty, ety) { |
| 4697 | (Some(Nim::Named(_, a)), Some(et)) if a.len() == 1 => { |
| 4698 | Some(Nim::Named("Result".into(), vec![a[0].clone(), et])) |
| 4699 | } |
| 4700 | _ => None, |
| 4701 | }; |
| 4702 | return Ok(v); |
| 4703 | } |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 4704 | "ok_or" => { |
| 4705 | let inner = match &rt { |
| 4706 | Some(Nim::Named(n, a)) if n == "Option" && a.len() == 1 => a[0].clone(), |
| 4707 | _ => return Err("`ok_or` needs a known `Option<T>` receiver".into()), |
| 4708 | }; |
| 4709 | let e = args.first().ok_or("`ok_or` takes one argument")?; |
| 4710 | let ety = e |
| 4711 | .ty |
| 4712 | .clone() |
| 4713 | .ok_or("`ok_or` needs a known error type for its argument")?; |
| 4714 | ( |
| 4715 | format!( |
| 4716 | "rsOkOr[{}, {}]({}, {})", |
| 4717 | inner.render(), |
| 4718 | ety.render(), |
| 4719 | recv.code, |
| 4720 | e.code |
| 4721 | ), |
| 4722 | Some(Nim::Named("Result".into(), vec![inner, ety])), |
| 4723 | ) |
| 4724 | } |
| 4725 | "unwrap_or" => { |
| 4726 | let inner = match &rt { |
| 4727 | Some(Nim::Named(n, a)) if (n == "Option" && a.len() == 1) || (n == "Result" && a.len() == 2) => { |
| 4728 | Some(a[0].clone()) |
| 4729 | } |
| 4730 | _ => None, |
| 4731 | }; |
| 4732 | ( |
| 4733 | format!("unwrapOr({}, {})", recv.code, a0.unwrap_or_default()), |
| 4734 | inner, |
| 4735 | ) |
| 4736 | } |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 4737 | "is_some" => (format!("{}.has", recv.code), Some(Nim::Prim("bool".into()))), |
| 4738 | "is_none" => (format!("(not {}.has)", recv.code), Some(Nim::Prim("bool".into()))), |
| 4739 | "is_ok" => (format!("{}.ok", recv.code), Some(Nim::Prim("bool".into()))), |
| 4740 | "is_err" => (format!("(not {}.ok)", recv.code), Some(Nim::Prim("bool".into()))), |
| 4741 | |
| 4742 | // Settled empirically: Nim's fixed-width *unsigned* arithmetic |
| 4743 | // wraps silently, matching Rust's `wrapping_*`. For *signed* types |
| 4744 | // Nim raises OverflowDefect, so the operation is routed through |
| 4745 | // the unsigned view of the same width, which is what Rust's |
| 4746 | // wrapping_* is defined to compute. |
| 4747 | "wrapping_add" | "wrapping_sub" | "wrapping_mul" => { |
| 4748 | let op = match name.as_str() { |
| 4749 | "wrapping_add" => "+", |
| 4750 | "wrapping_sub" => "-", |
| 4751 | _ => "*", |
| 4752 | }; |
| 4753 | let t = rt.clone().ok_or_else(|| { |
| 4754 | format!("`{name}` needs a known receiver type to pick the wrapping width") |
| 4755 | })?; |
| 4756 | if !t.is_integer() { |
| 4757 | return Err(format!("`{name}` on a non-integer type")); |
| 4758 | } |
| 4759 | let arg = a0.ok_or_else(|| format!("`{name}` takes one argument"))?; |
| 4760 | if t.is_unsigned() { |
| 4761 | (format!("({} {} {})", recv.code, op, arg), Some(t)) |
| 4762 | } else { |
| 4763 | let u = unsigned_peer(&t)?; |
| 4764 | ( |
| 4765 | format!( |
| 4766 | "cast[{}](cast[{}]({}) {} cast[{}]({}))", |
| 4767 | t.render(), u, recv.code, op, u, arg |
| 4768 | ), |
| 4769 | Some(t), |
| 4770 | ) |
| 4771 | } |
| 4772 | } |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 4773 | // Inside a formatting impl, a write through the `Formatter` *is* |
| 4774 | // the value the proc returns, so it lowers to the string written. |
| Add display.rs and the alloc half: all of base16ct now goes through afb2a6e nandithebull 9h ago | 4775 | "write_str" | "write_char" if self.is_fmt_param(&m.receiver) => { |
| 4776 | let a = args.first().ok_or("`write_str` takes one argument")?; |
| 4777 | // A `&str` argument is a character view, not a Nim string. |
| 4778 | let text = match &a.ty { |
| 4779 | Some(Nim::Prim(p)) if p == "string" => a.code.clone(), |
| 4780 | _ => format!("rsDisplay({})", a.code), |
| 4781 | }; |
| 4782 | (format!("result.add({})", text), Some(Nim::Unit)) |
| 4783 | } |
| Add generics; transpile the part of cosmic-theme that is reachable ff34e1b nandithebull 7h ago | 4784 | "saturating_add" | "saturating_sub" | "saturating_mul" | "checked_add" |
| 4785 | | "checked_sub" | "checked_mul" => { |
| 4786 | let t = rt |
| 4787 | .clone() |
| 4788 | .filter(|t| t.is_integer()) |
| 4789 | .ok_or_else(|| format!("`{name}` needs a known integer receiver"))?; |
| 4790 | let arg = args |
| 4791 | .first() |
| 4792 | .ok_or_else(|| format!("`{name}` takes one argument"))?; |
| 4793 | let f = match name.as_str() { |
| 4794 | "saturating_add" => "rsSatAdd", |
| 4795 | "saturating_sub" => "rsSatSub", |
| 4796 | "saturating_mul" => "rsSatMul", |
| 4797 | "checked_add" => "rsChkAdd", |
| 4798 | "checked_sub" => "rsChkSub", |
| 4799 | _ => "rsChkMul", |
| 4800 | }; |
| 4801 | let out = if name.starts_with("checked") { |
| 4802 | Nim::Named("Option".into(), vec![t]) |
| 4803 | } else { |
| 4804 | t |
| 4805 | }; |
| 4806 | (format!("{}({}, {})", f, recv.code, arg.code), Some(out)) |
| 4807 | } |
| Lower `extern "C"` blocks to Nim importc; do not transpile libc 7db7991 nandithebull 6h ago | 4808 | // `as_ptr` hands a C function the address of the first element, |
| 4809 | // which is what Rust's does. An empty slice has no first element |
| 4810 | // in either language, and reading through the pointer would be |
| 4811 | // undefined in both. |
| 4812 | "as_ptr" | "as_mut_ptr" => { |
| 4813 | let elem = elem_of(&rt) |
| 4814 | .ok_or("`as_ptr` needs a known element type")?; |
| 4815 | ( |
| 4816 | format!( |
| 4817 | "(if {r}.len == 0: nil else: cast[ptr {e}](addr {r}[0]))", |
| 4818 | r = recv.code, |
| 4819 | e = elem.render() |
| 4820 | ), |
| 4821 | Some(Nim::Ptr(Box::new(elem))), |
| 4822 | ) |
| 4823 | } |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 4824 | "abs" => (format!("abs({})", recv.code), rt.clone()), |
| 4825 | "min" => (format!("min({}, {})", recv.code, a0.unwrap_or_default()), rt.clone()), |
| 4826 | "max" => (format!("max({}, {})", recv.code, a0.unwrap_or_default()), rt.clone()), |
| 4827 | "to_string" => (format!("rsDisplay({})", recv.code), Some(Nim::Prim("string".into()))), |
| 4828 | "as_bytes" | "into_bytes" => ( |
| 4829 | format!("rsBytes({})", recv.code), |
| 4830 | Some(Nim::Seq(Box::new(Nim::Prim("uint8".into())))), |
| 4831 | ), |
| 4832 | |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 4833 | "into" => { |
| 4834 | // `.into()` resolves through the `impl From` declarations, and |
| 4835 | // needs the target type to pick one. |
| 4836 | let from = rt |
| 4837 | .clone() |
| 4838 | .ok_or("`.into()` needs a known receiver type")?; |
| 4839 | let to = expect |
| 4840 | .ok_or("`.into()` needs a known target type; annotate the binding")?; |
| 4841 | let key = (type_name(&from), type_name(to)); |
| 4842 | let f = self.from_impls.get(&key).cloned().ok_or_else(|| { |
| 4843 | format!( |
| 4844 | "no `impl From<{}> for {}` in this file, so `.into()` has \ |
| 4845 | no conversion to call", |
| 4846 | key.0, key.1 |
| 4847 | ) |
| 4848 | })?; |
| 4849 | (format!("{}({})", f, recv.code), Some(to.clone())) |
| 4850 | } |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 4851 | _ => { |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 4852 | // A method defined in this file via `impl`, found by the |
| 4853 | // receiver's type rather than by name alone. |
| 4854 | let key = rt.as_ref().map(|t| (type_name(t), name.clone())); |
| Add associated types and consts, and test whether the blocker stack bottoms out 8354895 nandithebull 7h ago | 4855 | // Re-lower the arguments with the declared parameter types: |
| 4856 | // a method's own signature says what width its literals are, |
| 4857 | // which the receiver's type does not. |
| 4858 | let declared: Option<Vec<Nim>> = key |
| 4859 | .as_ref() |
| 4860 | .and_then(|k| self.methods.get(k)) |
| 4861 | .map(|s| s.params.clone()); |
| 4862 | if let Some(d) = &declared { |
| 4863 | // params[0] is the receiver for a method with `self`. |
| 4864 | let skip = usize::from(d.len() == m.args.len() + 1); |
| 4865 | for (i, a) in m.args.iter().enumerate() { |
| 4866 | if let Some(want) = d.get(i + skip) { |
| 4867 | let want = want.clone().unvar(); |
| 4868 | args[i] = self.expr_at(a, Some(&want))?; |
| 4869 | } |
| 4870 | } |
| 4871 | } |
| Add generics; transpile the part of cosmic-theme that is reachable ff34e1b nandithebull 7h ago | 4872 | let mut arg_tys: Vec<Option<Nim>> = vec![recv.ty.clone()]; |
| 4873 | arg_tys.extend(args.iter().map(|a| a.ty.clone())); |
| Transpile a second crate, adler2, to test whether any of this generalises 5fdd5be nandithebull 8h ago | 4874 | let sig = key |
| 4875 | .as_ref() |
| 4876 | .and_then(|k| self.methods.get(k)) |
| Add generics; transpile the part of cosmic-theme that is reachable ff34e1b nandithebull 7h ago | 4877 | .map(|s| Self::instantiate(s, &arg_tys)); |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 4878 | if let Some(ret) = sig { |
| Transpile a second crate, adler2, to test whether any of this generalises 5fdd5be nandithebull 8h ago | 4879 | // Use the name the proc was actually emitted under: an |
| 4880 | // inherent method is qualified by its module, a trait |
| 4881 | // method by its trait. |
| 4882 | let nim = key |
| 4883 | .and_then(|k| self.statics.get(&k).cloned()) |
| 4884 | .unwrap_or_else(|| ident(&name)); |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 4885 | let mut all = vec![recv.code.clone()]; |
| 4886 | all.extend(args.iter().map(|a| a.code.clone())); |
| Transpile a second crate, adler2, to test whether any of this generalises 5fdd5be nandithebull 8h ago | 4887 | (format!("{}({})", nim, all.join(", ")), Some(ret)) |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 4888 | } else { |
| 4889 | return Err(format!( |
| 4890 | "unsupported method `.{name}()`; it is neither defined in \ |
| 4891 | this file nor part of the standard-library subset that \ |
| 4892 | has a verified Nim equivalent" |
| 4893 | )); |
| 4894 | } |
| 4895 | } |
| 4896 | }; |
| 4897 | Ok(Val::new(code, ty)) |
| 4898 | } |
| 4899 | |
| 4900 | // -------------------------------------------------------------- macros |
| 4901 | |
| Add closures and unsafe; base16ct's lower.rs and upper.rs go through 0a375d8 nandithebull 9h ago | 4902 | /// The element type of a `vec![..]`, from its first element. |
| 4903 | fn vec_elem(&mut self, mac: &syn::Macro) -> Result<Option<Nim>, String> { |
| 4904 | let body = mac.tokens.to_string(); |
| 4905 | if body.trim().is_empty() { |
| 4906 | return Ok(None); |
| 4907 | } |
| 4908 | let first: Option<Expr> = if body.contains(';') { |
| 4909 | // The whole body must be consumed or the parse fails, so the |
| 4910 | // length is parsed too even though only the element is wanted. |
| 4911 | mac.parse_body_with(|input: syn::parse::ParseStream| { |
| 4912 | let v: Expr = input.parse()?; |
| 4913 | input.parse::<syn::Token![;]>()?; |
| 4914 | let _len: Expr = input.parse()?; |
| 4915 | Ok(v) |
| 4916 | }) |
| 4917 | .ok() |
| 4918 | } else { |
| 4919 | mac.parse_body_with( |
| 4920 | syn::punctuated::Punctuated::<Expr, syn::Token![,]>::parse_terminated, |
| 4921 | ) |
| 4922 | .ok() |
| 4923 | .and_then(|p| p.into_iter().next()) |
| 4924 | }; |
| 4925 | match first { |
| 4926 | Some(e) => Ok(self.expr(&e)?.ty), |
| 4927 | None => Ok(None), |
| 4928 | } |
| 4929 | } |
| 4930 | |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 4931 | fn macro_call(&mut self, mac: &syn::Macro) -> Result<String, String> { |
| 4932 | let name = path_name(&mac.path); |
| 4933 | match name.as_str() { |
| 4934 | "println" | "print" | "eprintln" | "eprint" => { |
| 4935 | let s = self.format_args(mac)?; |
| 4936 | let nl = name.ends_with("ln"); |
| 4937 | Ok(match (name.starts_with('e'), nl) { |
| 4938 | (false, true) => format!("echo {s}"), |
| 4939 | (false, false) => format!("stdout.write({s})"), |
| 4940 | (true, true) => format!("stderr.writeLine({s})"), |
| 4941 | (true, false) => format!("stderr.write({s})"), |
| 4942 | }) |
| 4943 | } |
| 4944 | "format" => self.format_args(mac), |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 4945 | "write" | "writeln" => { |
| 4946 | // `write!(f, "..", ..)` inside a formatting impl: the first |
| 4947 | // argument is the sink, the rest is an ordinary format call. |
| 4948 | let args: Vec<Expr> = mac |
| 4949 | .parse_body_with(syn::punctuated::Punctuated::<Expr, syn::Token![,]>::parse_terminated) |
| 4950 | .map_err(|e| format!("write!: {e}"))? |
| 4951 | .into_iter() |
| 4952 | .collect(); |
| 4953 | let sink = args.first().ok_or("`write!` needs a sink")?; |
| 4954 | if !self.is_fmt_param(sink) { |
| 4955 | return Err("`write!` to anything but the `Formatter` of the \ |
| 4956 | enclosing formatting impl is not implemented" |
| 4957 | .into()); |
| 4958 | } |
| 4959 | let s = self.format_pieces(&args[1..])?; |
| Add display.rs and the alloc half: all of base16ct now goes through afb2a6e nandithebull 9h ago | 4960 | let s = if name == "writeln" { |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 4961 | format!("({} & \"\\n\")", s) |
| 4962 | } else { |
| 4963 | s |
| Add display.rs and the alloc half: all of base16ct now goes through afb2a6e nandithebull 9h ago | 4964 | }; |
| 4965 | Ok(format!("result.add({})", s)) |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 4966 | } |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 4967 | "panic" => { |
| 4968 | let s = self.format_args(mac)?; |
| 4969 | Ok(format!("rsPanic({s})")) |
| 4970 | } |
| Add display.rs and the alloc half: all of base16ct now goes through afb2a6e nandithebull 9h ago | 4971 | // `debug_assert*` fires in debug builds, which is the profile |
| 4972 | // this project models, so it lowers the same as `assert*`. |
| 4973 | "assert" | "debug_assert" => { |
| 4974 | let args: Vec<Expr> = mac |
| 4975 | .parse_body_with( |
| 4976 | syn::punctuated::Punctuated::<Expr, syn::Token![,]>::parse_terminated, |
| 4977 | ) |
| 4978 | .map_err(|e| format!("{name}!: {e}"))? |
| 4979 | .into_iter() |
| 4980 | .collect(); |
| 4981 | let cond = args.first().ok_or("`assert!` needs a condition")?; |
| 4982 | let v = self.expr(cond)?; |
| 4983 | let msg = if args.len() > 1 { |
| 4984 | self.format_pieces(&args[1..])? |
| 4985 | } else { |
| 4986 | fmt::nim_str("assertion failed") |
| 4987 | }; |
| 4988 | Ok(format!("(if not ({}): rsPanic({}))", v.code, msg)) |
| 4989 | } |
| 4990 | "assert_eq" | "assert_ne" | "debug_assert_eq" | "debug_assert_ne" => { |
| 4991 | let args: Vec<Expr> = mac |
| 4992 | .parse_body_with( |
| 4993 | syn::punctuated::Punctuated::<Expr, syn::Token![,]>::parse_terminated, |
| 4994 | ) |
| 4995 | .map_err(|e| format!("{name}!: {e}"))? |
| 4996 | .into_iter() |
| 4997 | .collect(); |
| 4998 | if args.len() < 2 { |
| 4999 | return Err(format!("`{name}!` takes two operands")); |
| 5000 | } |
| 5001 | let a = self.expr(&args[0])?; |
| 5002 | let b = self.expr_at(&args[1], a.ty.as_ref())?; |
| 5003 | let ne = name.ends_with("_ne"); |
| 5004 | let op = if ne { "!=" } else { "==" }; |
| 5005 | // Rust's message shows both sides; reproducing it keeps a |
| 5006 | // failing assertion as informative as the original. |
| 5007 | let label = if ne { "assertion failed: `(left != right)`" } else { "assertion failed: `(left == right)`" }; |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 5008 | Ok(format!( |
| Add display.rs and the alloc half: all of base16ct now goes through afb2a6e nandithebull 9h ago | 5009 | "(if not (({}) {} ({})): rsPanic({} & \"\\n left: \" & rsDebug({}) & \"\\n right: \" & rsDebug({})))", |
| 5010 | a.code, op, b.code, fmt::nim_str(label), a.code, b.code |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 5011 | )) |
| 5012 | } |
| Lower the `log` facade, and add explicit enum discriminants 12c0a01 nandithebull 6h ago | 5013 | // The `log` facade. See `src/prelude.nim` for why these are |
| 5014 | // lowered directly rather than expanded. The enabled check wraps |
| 5015 | // the whole thing because Rust does not evaluate a log record's |
| 5016 | // arguments when the level is disabled. |
| 5017 | "error" | "warn" | "info" | "debug" | "trace" | "log" => { |
| 5018 | let args: Vec<Expr> = mac |
| 5019 | .parse_body_with( |
| 5020 | syn::punctuated::Punctuated::<Expr, syn::Token![,]>::parse_terminated, |
| 5021 | ) |
| 5022 | .map_err(|e| format!("`{name}!`: {e}"))? |
| 5023 | .into_iter() |
| 5024 | .collect(); |
| 5025 | let (level, rest) = if name == "log" { |
| 5026 | let first = args.first().ok_or("`log!` needs a level")?; |
| 5027 | (self.log_level_of(first)?, &args[1..]) |
| 5028 | } else { |
| 5029 | ( |
| 5030 | match name.as_str() { |
| 5031 | "error" => "rsLvlError", |
| 5032 | "warn" => "rsLvlWarn", |
| 5033 | "info" => "rsLvlInfo", |
| 5034 | "debug" => "rsLvlDebug", |
| 5035 | _ => "rsLvlTrace", |
| 5036 | } |
| 5037 | .to_string(), |
| 5038 | &args[..], |
| 5039 | ) |
| 5040 | }; |
| 5041 | let msg = self.format_pieces(rest)?; |
| 5042 | let target = fmt::nim_str(&self.cur_mod.clone()); |
| 5043 | Ok(format!( |
| 5044 | "(if rsLogEnabled({lvl}): rsLog({lvl}, {target}, {msg}))", |
| 5045 | lvl = level |
| 5046 | )) |
| 5047 | } |
| 5048 | "log_enabled" => { |
| 5049 | let e: Expr = mac |
| 5050 | .parse_body() |
| 5051 | .map_err(|e| format!("`log_enabled!`: {e}"))?; |
| 5052 | let l = self.log_level_of(&e)?; |
| 5053 | Ok(format!("rsLogEnabled({l})")) |
| 5054 | } |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 5055 | "vec" => { |
| 5056 | let body = mac.tokens.to_string(); |
| 5057 | if body.trim().is_empty() { |
| 5058 | return Ok("@[]".into()); |
| 5059 | } |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 5060 | // `vec![elem; n]` is the repeat form, not a list. The macro |
| 5061 | // body has no brackets, so it is parsed directly. |
| 5062 | if body.contains(';') { |
| 5063 | let (v, n) = mac |
| 5064 | .parse_body_with(|input: syn::parse::ParseStream| { |
| 5065 | let v: Expr = input.parse()?; |
| 5066 | input.parse::<syn::Token![;]>()?; |
| 5067 | let n: Expr = input.parse()?; |
| 5068 | Ok((v, n)) |
| 5069 | }) |
| 5070 | .map_err(|e| format!("vec![elem; n]: {e}"))?; |
| Add closures and unsafe; base16ct's lower.rs and upper.rs go through 0a375d8 nandithebull 9h ago | 5071 | let want = self.vec_expect.clone(); |
| 5072 | let v = self.expr_at(&v, want.as_ref())?; |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 5073 | let n = self.expr(&n)?; |
| 5074 | return Ok(format!("newSeqWith(int({}), {})", n.code, v.code)); |
| 5075 | } |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 5076 | let elems: syn::punctuated::Punctuated<Expr, syn::Token![,]> = mac |
| 5077 | .parse_body_with(syn::punctuated::Punctuated::parse_terminated) |
| 5078 | .map_err(|e| format!("vec!: {e}"))?; |
| Add closures and unsafe; base16ct's lower.rs and upper.rs go through 0a375d8 nandithebull 9h ago | 5079 | let want = self.vec_expect.clone(); |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 5080 | let mut parts = Vec::new(); |
| 5081 | for e in &elems { |
| Add closures and unsafe; base16ct's lower.rs and upper.rs go through 0a375d8 nandithebull 9h ago | 5082 | parts.push(self.expr_at(e, want.as_ref())?.code); |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 5083 | } |
| 5084 | Ok(format!("@[{}]", parts.join(", "))) |
| 5085 | } |
| Expand `macro_rules!` rather than translating it to a Nim template 04eb29f nandithebull 6h ago | 5086 | other => { |
| 5087 | if let Some(why) = self.mrules_bad.get(other) { |
| 5088 | return Err(format!("`{other}!` cannot be expanded: {why}")); |
| 5089 | } |
| 5090 | if let Some(def) = self.mrules.get(other).cloned() { |
| Expand multi-rule and recursive macro_rules d459281 nandithebull 5h ago | 5091 | // A multi-rule macro commonly recurses, shedding one |
| 5092 | // argument per step. The depth limit turns a macro that |
| 5093 | // does not terminate into an error rather than a hang. |
| 5094 | if self.macro_depth > 64 { |
| 5095 | return Err(format!( |
| 5096 | "`{other}!` expanded more than 64 levels deep; it \ |
| 5097 | does not appear to terminate" |
| 5098 | )); |
| 5099 | } |
| Expand `macro_rules!` rather than translating it to a Nim template 04eb29f nandithebull 6h ago | 5100 | let expanded = def |
| 5101 | .expand(mac.tokens.clone()) |
| 5102 | .map_err(|e| format!("expanding `{other}!`: {e}"))?; |
| 5103 | // The expansion is ordinary Rust, lowered in a context |
| 5104 | // where its types are known. |
| 5105 | let e: Expr = syn::parse2(expanded.clone()).map_err(|_| { |
| 5106 | format!( |
| 5107 | "`{other}!` expands to something that is not an \ |
| 5108 | expression: `{}`", |
| 5109 | expanded |
| 5110 | ) |
| 5111 | })?; |
| Expand multi-rule and recursive macro_rules d459281 nandithebull 5h ago | 5112 | self.macro_depth += 1; |
| 5113 | let r = self.expr(&e); |
| 5114 | self.macro_depth -= 1; |
| 5115 | return Ok(r?.code); |
| Expand `macro_rules!` rather than translating it to a Nim template 04eb29f nandithebull 6h ago | 5116 | } |
| 5117 | Err(format!( |
| 5118 | "unsupported macro `{other}!`; a macro whose expansion is not \ |
| 5119 | known cannot be lowered faithfully" |
| 5120 | )) |
| 5121 | } |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 5122 | } |
| 5123 | } |
| 5124 | |
| 5125 | /// `println!("{} {}", a, b)` -> a Nim string-concatenation expression. |
| 5126 | fn format_args(&mut self, mac: &syn::Macro) -> Result<String, String> { |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 5127 | let args: Vec<Expr> = mac |
| 5128 | .parse_body_with(syn::punctuated::Punctuated::<Expr, syn::Token![,]>::parse_terminated) |
| 5129 | .map_err(|e| format!("format arguments: {e}"))? |
| 5130 | .into_iter() |
| 5131 | .collect(); |
| 5132 | self.format_pieces(&args) |
| 5133 | } |
| 5134 | |
| 5135 | /// `["{} {}", a, b]` -> a Nim string-concatenation expression. |
| 5136 | fn format_pieces(&mut self, args: &[Expr]) -> Result<String, String> { |
| 5137 | let Some(Expr::Lit(syn::ExprLit { lit: Lit::Str(s), .. })) = args.first() else { |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 5138 | if args.is_empty() { |
| 5139 | return Ok("\"\"".into()); |
| 5140 | } |
| 5141 | return Err("the first argument must be a literal format string".into()); |
| 5142 | }; |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 5143 | let rest: Vec<&Expr> = args[1..].iter().collect(); |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 5144 | |
| 5145 | let pieces = fmt::parse(&s.value())?; |
| 5146 | let mut parts: Vec<String> = Vec::new(); |
| 5147 | let mut next = 0usize; |
| 5148 | let mut used = vec![false; rest.len()]; |
| 5149 | for p in &pieces { |
| 5150 | match p { |
| 5151 | fmt::Piece::Lit(l) => parts.push(fmt::nim_str(l)), |
| 5152 | fmt::Piece::Arg { r#ref, spec } => { |
| 5153 | let v = match r#ref { |
| 5154 | fmt::Ref::Next => { |
| 5155 | let e = rest.get(next).ok_or("too few arguments for format string")?; |
| 5156 | used[next] = true; |
| 5157 | next += 1; |
| 5158 | self.expr(e)? |
| 5159 | } |
| 5160 | fmt::Ref::Index(i) => { |
| 5161 | let e = rest.get(*i).ok_or("format index out of range")?; |
| 5162 | used[*i] = true; |
| 5163 | self.expr(e)? |
| 5164 | } |
| 5165 | fmt::Ref::Named(n) => { |
| 5166 | let t = self.lookup(n).ok_or_else(|| { |
| 5167 | format!("`{{{n}}}` captures `{n}`, which is not in scope") |
| 5168 | })?; |
| 5169 | Val::new(ident(n), Some(t)) |
| 5170 | } |
| 5171 | }; |
| Add display.rs and the alloc half: all of base16ct now goes through afb2a6e nandithebull 9h ago | 5172 | let integer = v.ty.as_ref().is_some_and(|t| t.is_integer()); |
| 5173 | if spec.radix.is_some() && !integer && v.ty.is_none() { |
| 5174 | return Err( |
| 5175 | "a radix format (`{:x}`, `{:b}`, ...) needs a known \ |
| 5176 | argument type: on an integer it formats the bit \ |
| 5177 | pattern, on anything else it calls that type's own \ |
| 5178 | impl" |
| 5179 | .into(), |
| 5180 | ); |
| 5181 | } |
| 5182 | parts.push(fmt::render_arg(&v.code, spec, integer)); |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 5183 | } |
| 5184 | } |
| 5185 | } |
| 5186 | // Rust rejects an argument that no `{}` consumes; so do we, rather |
| 5187 | // than dropping it from the output. |
| 5188 | if let Some(i) = used.iter().position(|u| !u) { |
| 5189 | return Err(format!( |
| 5190 | "argument {} is never used by the format string", |
| 5191 | i + 1 |
| 5192 | )); |
| 5193 | } |
| 5194 | Ok(if parts.is_empty() { "\"\"".into() } else { parts.join(" & ") }) |
| 5195 | } |
| 5196 | } |
| 5197 | |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 5198 | /// Whether a pattern introduces a binding. |
| 5199 | fn binds(p: &Pat) -> bool { |
| 5200 | match p { |
| 5201 | Pat::Ident(_) => true, |
| 5202 | Pat::Guard(g) => binds(&g.pat), |
| 5203 | Pat::Paren(x) => binds(&x.pat), |
| 5204 | Pat::Reference(r) => binds(&r.pat), |
| 5205 | Pat::Or(o) => o.cases.iter().any(binds), |
| 5206 | Pat::TupleStruct(t) => t.elems.iter().any(|_| true), |
| 5207 | Pat::Struct(_) | Pat::Tuple(_) | Pat::Slice(_) => true, |
| 5208 | _ => false, |
| 5209 | } |
| 5210 | } |
| 5211 | |
| 5212 | /// Whether a pattern looks inside the value, which a Nim `case` cannot do. |
| 5213 | fn destructures(p: &Pat) -> bool { |
| 5214 | matches!( |
| 5215 | p, |
| 5216 | Pat::TupleStruct(_) | Pat::Struct(_) | Pat::Tuple(_) | Pat::Slice(_) |
| 5217 | ) || matches!(p, Pat::Guard(g) if destructures(&g.pat)) |
| 5218 | || matches!(p, Pat::Paren(x) if destructures(&x.pat)) |
| 5219 | || matches!(p, Pat::Reference(r) if destructures(&r.pat)) |
| 5220 | } |
| 5221 | |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 5222 | /// Whether an expression has a direct Nim expression form. |
| 5223 | /// |
| 5224 | /// Nim's `if` is an expression only when every arm is a single expression, and |
| 5225 | /// its `case` is never one here. Anything else has to be lowered as statements |
| 5226 | /// that assign into a target. |
| 5227 | fn expressible(e: &Expr) -> bool { |
| 5228 | match e { |
| 5229 | Expr::If(i) => { |
| 5230 | let Some(then) = single_expr(&i.then_branch) else { return false }; |
| 5231 | if !expressible(then) { |
| 5232 | return false; |
| 5233 | } |
| 5234 | match &i.else_branch { |
| 5235 | None => false, |
| 5236 | Some((_, els)) => match &**els { |
| 5237 | Expr::Block(b) => single_expr(&b.block).is_some_and(expressible), |
| 5238 | other => expressible(other), |
| 5239 | }, |
| 5240 | } |
| 5241 | } |
| Lower `extern "C"` blocks to Nim importc; do not transpile libc 7db7991 nandithebull 6h ago | 5242 | // `unsafe { .. }` is transparent, so it is an expression exactly when |
| 5243 | // its block is one. |
| 5244 | Expr::Unsafe(u) => single_expr(&u.block).is_some_and(expressible), |
| Expand `$(..)` repetition in macro_rules 3d4a7d2 nandithebull 6h ago | 5245 | Expr::Block(b) => { |
| 5246 | b.label.is_none() && matches!(b.block.stmts.last(), Some(Stmt::Expr(_, None))) |
| 5247 | } |
| 5248 | Expr::Match(_) | Expr::Loop(_) | Expr::While(_) | Expr::ForLoop(_) => false, |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 5249 | _ => true, |
| 5250 | } |
| 5251 | } |
| 5252 | |
| 5253 | /// The single expression a block consists of, if that is all it is. An `if` |
| 5254 | /// can only be lowered as a Nim `if`-expression when both arms are this shape. |
| 5255 | fn single_expr(b: &syn::Block) -> Option<&Expr> { |
| 5256 | match (b.stmts.len(), b.stmts.first()) { |
| 5257 | (1, Some(Stmt::Expr(e, None))) => Some(e), |
| 5258 | _ => None, |
| 5259 | } |
| 5260 | } |
| 5261 | |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 5262 | /// Substitute `params[i] -> args[i]` through a type. Enough of the type |
| 5263 | /// grammar is covered to expand the aliases we accept; anything else is left |
| 5264 | /// alone and will be reported by `ty::map` if it is unsupported. |
| 5265 | fn substitute(t: &syn::Type, params: &[String], args: &[syn::Type]) -> syn::Type { |
| 5266 | use syn::Type; |
| 5267 | match t { |
| 5268 | Type::Path(p) => { |
| 5269 | if p.qself.is_none() && p.path.segments.len() == 1 { |
| 5270 | let seg = &p.path.segments[0]; |
| 5271 | if seg.arguments.is_empty() { |
| 5272 | let name = seg.ident.to_string(); |
| 5273 | if let Some(i) = params.iter().position(|x| *x == name) { |
| 5274 | return args[i].clone(); |
| 5275 | } |
| 5276 | } |
| 5277 | } |
| 5278 | let mut p = p.clone(); |
| 5279 | for seg in &mut p.path.segments { |
| 5280 | if let syn::PathArguments::AngleBracketed(a) = &mut seg.arguments { |
| 5281 | for g in &mut a.args { |
| 5282 | if let syn::GenericArgument::Type(t) = g { |
| 5283 | *t = substitute(t, params, args); |
| 5284 | } |
| 5285 | } |
| 5286 | } |
| 5287 | } |
| 5288 | Type::Path(p) |
| 5289 | } |
| 5290 | Type::Reference(r) => { |
| 5291 | let mut r = r.clone(); |
| 5292 | r.elem = Box::new(substitute(&r.elem, params, args)); |
| 5293 | Type::Reference(r) |
| 5294 | } |
| 5295 | Type::Slice(sl) => { |
| 5296 | let mut sl = sl.clone(); |
| 5297 | sl.elem = Box::new(substitute(&sl.elem, params, args)); |
| 5298 | Type::Slice(sl) |
| 5299 | } |
| 5300 | Type::Array(a) => { |
| 5301 | let mut a = a.clone(); |
| 5302 | a.elem = Box::new(substitute(&a.elem, params, args)); |
| 5303 | Type::Array(a) |
| 5304 | } |
| 5305 | Type::Tuple(tp) => { |
| 5306 | let mut tp = tp.clone(); |
| 5307 | tp.elems = tp.elems.iter().map(|e| substitute(e, params, args)).collect(); |
| 5308 | Type::Tuple(tp) |
| 5309 | } |
| 5310 | Type::Paren(p) => substitute(&p.elem, params, args), |
| 5311 | Type::Group(g) => substitute(&g.elem, params, args), |
| 5312 | other => other.clone(), |
| 5313 | } |
| 5314 | } |
| 5315 | |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 5316 | // --------------------------------------------------------------- utilities |
| 5317 | |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 5318 | /// Whether a return type is a borrow of one of the arguments, which Nim |
| 5319 | /// models with a view rather than with an owned copy. |
| 5320 | fn returns_borrow(t: &syn::Type) -> bool { |
| 5321 | match t { |
| Add closures and unsafe; base16ct's lower.rs and upper.rs go through 0a375d8 nandithebull 9h ago | 5322 | syn::Type::Reference(r) => match &*r.elem { |
| 5323 | syn::Type::Slice(_) => true, |
| 5324 | // `&str` is a borrow of someone else's bytes too, and returning it |
| 5325 | // means returning a view, not an owned string. |
| 5326 | syn::Type::Path(p) => p.path.is_ident("str"), |
| 5327 | _ => false, |
| 5328 | }, |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 5329 | syn::Type::Paren(p) => returns_borrow(&p.elem), |
| 5330 | syn::Type::Group(g) => returns_borrow(&g.elem), |
| 5331 | _ => false, |
| 5332 | } |
| 5333 | } |
| 5334 | |
| Add closures and unsafe; base16ct's lower.rs and upper.rs go through 0a375d8 nandithebull 9h ago | 5335 | /// The module a `use` prefix names. `crate`, `self` and `super` all resolve |
| 5336 | /// to the crate root, which is where a flattened module's items live unless |
| 5337 | /// they came from one of the extra input files. |
| 5338 | fn module_of(prefix: &[String]) -> String { |
| 5339 | match prefix.last() { |
| 5340 | Some(m) if m != "crate" && m != "self" && m != "super" => m.clone(), |
| 5341 | _ => String::new(), |
| 5342 | } |
| 5343 | } |
| 5344 | |
| 5345 | /// The first type argument of an `Option[T]` / `Result[T, E]`. |
| 5346 | fn elem_arg(t: &Nim) -> Nim { |
| 5347 | match t { |
| 5348 | Nim::Named(_, a) if !a.is_empty() => a[0].clone(), |
| 5349 | other => other.clone(), |
| 5350 | } |
| 5351 | } |
| 5352 | |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 5353 | /// The element type of a sequence-like Nim type. |
| 5354 | fn elem_of(t: &Option<Nim>) -> Option<Nim> { |
| 5355 | match t { |
| 5356 | Some(Nim::Seq(e)) | Some(Nim::OpenArray(e)) | Some(Nim::Array(_, e)) => Some((**e).clone()), |
| 5357 | Some(Nim::Prim(p)) if p == "string" => Some(Nim::Prim("char".into())), |
| 5358 | _ => None, |
| 5359 | } |
| 5360 | } |
| 5361 | |
| 5362 | /// The short name a Nim type is known by, for keying method tables. |
| 5363 | fn type_name(t: &Nim) -> String { |
| 5364 | match t { |
| 5365 | Nim::Named(n, _) => n.clone(), |
| 5366 | Nim::Prim(p) => p.clone(), |
| 5367 | other => other.render(), |
| 5368 | } |
| 5369 | } |
| 5370 | |
| Transpile a second crate, adler2, to test whether any of this generalises 5fdd5be nandithebull 8h ago | 5371 | /// `(trait, operator)` for every operator trait we dispatch. |
| 5372 | const OPERATOR_TRAITS: &[(&str, &str)] = &[ |
| 5373 | ("Add", "+"), ("Sub", "-"), ("Mul", "*"), ("Div", "/"), ("Rem", "%"), |
| 5374 | ("BitAnd", "&"), ("BitOr", "|"), ("BitXor", "^"), ("Shl", "<<"), ("Shr", ">>"), |
| 5375 | ("AddAssign", "+="), ("SubAssign", "-="), ("MulAssign", "*="), ("DivAssign", "/="), |
| 5376 | ("RemAssign", "%="), ("BitAndAssign", "&="), ("BitOrAssign", "|="), |
| 5377 | ("BitXorAssign", "^="), ("ShlAssign", "<<="), ("ShrAssign", ">>="), |
| 5378 | ("Neg", "neg"), ("Not", "not"), |
| 5379 | ]; |
| 5380 | |
| 5381 | /// `(operator, trait method name)`. |
| 5382 | const OP_METHOD: &[(&str, &str)] = &[ |
| 5383 | ("+", "add"), ("-", "sub"), ("*", "mul"), ("/", "div"), ("%", "rem"), |
| 5384 | ("&", "bitand"), ("|", "bitor"), ("^", "bitxor"), ("<<", "shl"), (">>", "shr"), |
| 5385 | ("+=", "add_assign"), ("-=", "sub_assign"), ("*=", "mul_assign"), |
| 5386 | ("/=", "div_assign"), ("%=", "rem_assign"), ("&=", "bitand_assign"), |
| 5387 | ("|=", "bitor_assign"), ("^=", "bitxor_assign"), ("<<=", "shl_assign"), |
| 5388 | (">>=", "shr_assign"), ("neg", "neg"), ("not", "not"), |
| 5389 | ]; |
| 5390 | |
| 5391 | fn op_method(op: &str) -> &'static str { |
| 5392 | OP_METHOD.iter().find(|(o, _)| *o == op).map(|(_, m)| *m).unwrap_or("") |
| 5393 | } |
| 5394 | |
| 5395 | /// The operator symbol a compound assignment applies. |
| 5396 | fn compound_symbol(op: &BinOp) -> &'static str { |
| 5397 | match op { |
| 5398 | BinOp::AddAssign(_) => "+=", |
| 5399 | BinOp::SubAssign(_) => "-=", |
| 5400 | BinOp::MulAssign(_) => "*=", |
| 5401 | BinOp::DivAssign(_) => "/=", |
| 5402 | BinOp::RemAssign(_) => "%=", |
| 5403 | BinOp::BitAndAssign(_) => "&=", |
| 5404 | BinOp::BitOrAssign(_) => "|=", |
| 5405 | BinOp::BitXorAssign(_) => "^=", |
| 5406 | BinOp::ShlAssign(_) => "<<=", |
| 5407 | BinOp::ShrAssign(_) => ">>=", |
| 5408 | _ => "", |
| 5409 | } |
| 5410 | } |
| 5411 | |
| 5412 | fn binary_symbol(op: &BinOp) -> &'static str { |
| 5413 | match op { |
| 5414 | BinOp::Add(_) => "+", |
| 5415 | BinOp::Sub(_) => "-", |
| 5416 | BinOp::Mul(_) => "*", |
| 5417 | BinOp::Div(_) => "/", |
| 5418 | BinOp::Rem(_) => "%", |
| 5419 | BinOp::BitAnd(_) => "&", |
| 5420 | BinOp::BitOr(_) => "|", |
| 5421 | BinOp::BitXor(_) => "^", |
| 5422 | BinOp::Shl(_) => "<<", |
| 5423 | BinOp::Shr(_) => ">>", |
| 5424 | _ => "", |
| 5425 | } |
| 5426 | } |
| 5427 | |
| 5428 | /// The operator a trait overloads, if it is one of the operator traits. |
| 5429 | fn operator_trait(t: &str) -> Option<&'static str> { |
| 5430 | Some(match t { |
| 5431 | "Add" => "+", |
| 5432 | "Sub" => "-", |
| 5433 | "Mul" => "*", |
| 5434 | "Div" => "/", |
| 5435 | "Rem" => "%", |
| 5436 | "BitAnd" => "&", |
| 5437 | "BitOr" => "|", |
| 5438 | "BitXor" => "^", |
| 5439 | "Shl" => "<<", |
| 5440 | "Shr" => ">>", |
| 5441 | "AddAssign" => "+=", |
| 5442 | "SubAssign" => "-=", |
| 5443 | "MulAssign" => "*=", |
| 5444 | "DivAssign" => "/=", |
| 5445 | "RemAssign" => "%=", |
| 5446 | "BitAndAssign" => "&=", |
| 5447 | "BitOrAssign" => "|=", |
| 5448 | "BitXorAssign" => "^=", |
| 5449 | "ShlAssign" => "<<=", |
| 5450 | "ShrAssign" => ">>=", |
| 5451 | "Neg" => "neg", |
| 5452 | "Not" => "not", |
| 5453 | _ => return None, |
| 5454 | }) |
| 5455 | } |
| 5456 | |
| 5457 | /// The Nim proc name for a trait method, qualified by trait and type so that |
| 5458 | /// two traits declaring the same method name cannot collide. |
| 5459 | fn trait_method_name(ty: &str, tr: &str, m: &str) -> String { |
| 5460 | format!("rs{}_{}_{}", tr, ty, m) |
| 5461 | } |
| 5462 | |
| Add trait impls and slice iterators; base16ct's decoder now goes through ae9f986 nandithebull 9h ago | 5463 | fn is_fmt_trait(t: &str) -> bool { |
| 5464 | matches!(t, "Display" | "Debug" | "LowerHex" | "UpperHex" | "Binary" | "Octal") |
| 5465 | } |
| 5466 | |
| 5467 | /// The prelude proc a formatting trait's output is produced by. |
| 5468 | fn fmt_proc(t: &str) -> &'static str { |
| 5469 | match t { |
| 5470 | "Display" => "rsDisplay", |
| 5471 | "Debug" => "rsDebug", |
| 5472 | "LowerHex" => "rsLowerHex", |
| 5473 | "UpperHex" => "rsUpperHex", |
| 5474 | "Binary" => "rsBinary", |
| 5475 | _ => "rsOctal", |
| 5476 | } |
| 5477 | } |
| 5478 | |
| Transpile a second crate, adler2, to test whether any of this generalises 5fdd5be nandithebull 8h ago | 5479 | /// Whether an expression is an iterator-producing chain rather than a value. |
| 5480 | fn is_iterator_expr(e: &Expr) -> bool { |
| 5481 | match e { |
| 5482 | Expr::MethodCall(m) => matches!( |
| 5483 | m.method.to_string().as_str(), |
| 5484 | "iter" | "iter_mut" | "into_iter" | "enumerate" | "zip" | "chunks_exact" |
| 5485 | | "chunks_exact_mut" | "windows" |
| 5486 | ), |
| 5487 | Expr::Paren(p) => is_iterator_expr(&p.expr), |
| 5488 | _ => false, |
| 5489 | } |
| 5490 | } |
| 5491 | |
| Prove byte-identity for base16ct by enumerating whole input domains 99b8376 nandithebull 8h ago | 5492 | /// Whether an expression denotes a place -- a variable, a field, or an index |
| 5493 | /// or slice of one -- and so may be re-evaluated with no side effect. |
| 5494 | fn is_pure_place(e: &Expr) -> bool { |
| 5495 | match e { |
| 5496 | Expr::Path(_) => true, |
| 5497 | Expr::Field(f) => is_pure_place(&f.base), |
| 5498 | Expr::Index(i) => { |
| 5499 | is_pure_place(&i.expr) |
| 5500 | && match &*i.index { |
| 5501 | Expr::Range(r) => { |
| 5502 | r.start.as_deref().map_or(true, is_pure_place) |
| 5503 | && r.end.as_deref().map_or(true, is_pure_place) |
| 5504 | } |
| 5505 | other => is_pure_place(other), |
| 5506 | } |
| 5507 | } |
| 5508 | Expr::Lit(_) => true, |
| 5509 | Expr::Reference(r) => is_pure_place(&r.expr), |
| 5510 | Expr::Paren(p) => is_pure_place(&p.expr), |
| 5511 | Expr::Group(g) => is_pure_place(&g.expr), |
| 5512 | // Arithmetic on places is still side-effect free, so a bound like |
| 5513 | // `..want - 1` does not stop the binding being an alias. |
| 5514 | Expr::Binary(b) if !is_compound(&b.op) => { |
| 5515 | is_pure_place(&b.left) && is_pure_place(&b.right) |
| 5516 | } |
| 5517 | Expr::Unary(u) => is_pure_place(&u.expr), |
| 5518 | Expr::Cast(c) => is_pure_place(&c.expr), |
| 5519 | _ => false, |
| 5520 | } |
| 5521 | } |
| 5522 | |
| 5523 | /// Whether an expression is a `&mut` borrow, directly or through parens. |
| 5524 | fn is_mut_borrow(e: &Expr) -> bool { |
| 5525 | match e { |
| 5526 | Expr::Reference(r) => r.mutability.is_some(), |
| 5527 | Expr::Paren(p) => is_mut_borrow(&p.expr), |
| 5528 | Expr::Group(g) => is_mut_borrow(&g.expr), |
| 5529 | _ => false, |
| 5530 | } |
| 5531 | } |
| 5532 | |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 5533 | fn takes_self(sig: &syn::Signature) -> bool { |
| 5534 | matches!(sig.inputs.first(), Some(FnArg::Receiver(_))) |
| 5535 | } |
| 5536 | |
| 5537 | fn path_name(p: &syn::Path) -> String { |
| 5538 | p.segments |
| 5539 | .last() |
| 5540 | .map(|s| s.ident.to_string()) |
| 5541 | .unwrap_or_default() |
| 5542 | } |
| 5543 | |
| 5544 | fn is_compound(op: &BinOp) -> bool { |
| 5545 | matches!( |
| 5546 | op, |
| 5547 | BinOp::AddAssign(_) |
| 5548 | | BinOp::SubAssign(_) |
| 5549 | | BinOp::MulAssign(_) |
| 5550 | | BinOp::DivAssign(_) |
| 5551 | | BinOp::RemAssign(_) |
| 5552 | | BinOp::BitAndAssign(_) |
| 5553 | | BinOp::BitOrAssign(_) |
| 5554 | | BinOp::BitXorAssign(_) |
| 5555 | | BinOp::ShlAssign(_) |
| 5556 | | BinOp::ShrAssign(_) |
| 5557 | ) |
| 5558 | } |
| 5559 | |
| 5560 | /// The Nim literal suffix for an integer type (`5'i32`). |
| 5561 | fn nim_suffix(t: &Nim) -> Result<&'static str, String> { |
| 5562 | let Nim::Prim(p) = t else { |
| 5563 | return Err("not a primitive integer".into()); |
| 5564 | }; |
| 5565 | Ok(match p.as_str() { |
| 5566 | "int8" => "i8", |
| 5567 | "int16" => "i16", |
| 5568 | "int32" => "i32", |
| 5569 | "int64" => "i64", |
| 5570 | "int" => "i", |
| 5571 | "uint8" => "u8", |
| 5572 | "uint16" => "u16", |
| 5573 | "uint32" => "u32", |
| 5574 | "uint64" => "u64", |
| 5575 | "uint" => "u", |
| 5576 | other => return Err(format!("no Nim literal suffix for `{other}`")), |
| 5577 | }) |
| 5578 | } |
| 5579 | |
| 5580 | /// The unsigned integer type of the same width, used to spell `wrapping_*`. |
| 5581 | fn unsigned_peer(t: &Nim) -> Result<&'static str, String> { |
| 5582 | let Nim::Prim(p) = t else { |
| 5583 | return Err("not a primitive integer".into()); |
| 5584 | }; |
| 5585 | Ok(match p.as_str() { |
| 5586 | "int8" => "uint8", |
| 5587 | "int16" => "uint16", |
| 5588 | "int32" => "uint32", |
| 5589 | "int64" => "uint64", |
| 5590 | "int" => "uint", |
| 5591 | other => return Err(format!("`{other}` has no unsigned peer")), |
| 5592 | }) |
| 5593 | } |
| 5594 | |
| Add enums, Option/Result, `?`, and the machinery base16ct needs around them b0ccd80 nandithebull 10h ago | 5595 | fn quote_meta(m: &syn::Meta) -> String { |
| 5596 | match m { |
| 5597 | syn::Meta::Path(p) => path_name(p), |
| 5598 | syn::Meta::List(l) => format!("{}(..)", path_name(&l.path)), |
| 5599 | syn::Meta::NameValue(nv) => format!("{} = ..", path_name(&nv.path)), |
| 5600 | } |
| 5601 | } |
| 5602 | |
| 5603 | fn item_attrs(i: &Item) -> &[syn::Attribute] { |
| 5604 | match i { |
| 5605 | Item::Fn(f) => &f.attrs, |
| 5606 | Item::Struct(s) => &s.attrs, |
| 5607 | Item::Enum(e) => &e.attrs, |
| 5608 | Item::Impl(x) => &x.attrs, |
| 5609 | Item::Const(c) => &c.attrs, |
| 5610 | Item::Type(t) => &t.attrs, |
| 5611 | Item::Mod(m) => &m.attrs, |
| 5612 | Item::Use(u) => &u.attrs, |
| 5613 | Item::ExternCrate(e) => &e.attrs, |
| 5614 | Item::Static(s) => &s.attrs, |
| 5615 | _ => &[], |
| 5616 | } |
| 5617 | } |
| 5618 | |
| Add the differential test runner, and a lowering to measure with it 8ac32af nandithebull 10h ago | 5619 | fn item_kind(i: &Item) -> &'static str { |
| 5620 | match i { |
| 5621 | Item::Trait(_) => "`trait`", |
| 5622 | Item::Static(_) => "`static`", |
| 5623 | Item::Macro(_) => "macro definition", |
| 5624 | Item::Union(_) => "`union`", |
| 5625 | _ => "item", |
| 5626 | } |
| 5627 | } |
| 5628 | |
| 5629 | fn expr_kind(e: &Expr) -> &'static str { |
| 5630 | match e { |
| 5631 | Expr::Async(_) => "`async` block", |
| 5632 | Expr::Await(_) => "`.await`", |
| 5633 | Expr::Try(_) => "`?`", |
| 5634 | Expr::Range(_) => "range", |
| 5635 | Expr::Match(_) => "`match` (only statement position is implemented)", |
| 5636 | Expr::Let(_) => "`let` expression", |
| 5637 | Expr::Unsafe(_) => "`unsafe` block", |
| 5638 | Expr::Loop(_) | Expr::While(_) | Expr::ForLoop(_) => "loop (has no value in Nim)", |
| 5639 | _ => "expression", |
| 5640 | } |
| 5641 | } |