| 📦 Turbo Golo d710c1b k33g 12h ago | 1 | package gololang |
| 2 | |
| 3 | // The quoted literals of Golo: "strings", """multi-line strings""" and |
| 4 | // 'characters', and the one rule that governs all three — each runs to its |
| 5 | // closing quote, wherever that quote is. |
| 6 | |
| 7 | import "rickub.com/turbo-editors/turbo-core/syntax" |
| 8 | |
| 9 | // multilineStringQuote opens and closes a multi-line string. Inside one the |
| 10 | // lexer interprets nothing — no escape, no interpolation — so the only thing |
| 11 | // that can end it is these three runes. |
| 12 | const multilineStringQuote = `"""` |
| 13 | |
| 14 | // takeQuoted colours a "…" or '…' literal from its opening quote to its |
| 15 | // closing one, and reports it as still open when the line ends first. |
| 16 | // |
| 17 | // Carrying it is the honest reading of the language. The interpreter reads a |
| 18 | // string to its closing quote and nothing stops it at a newline, so a line |
| 19 | // ending inside a literal is not broken source — it is a literal with a line |
| 20 | // break in it — and stopping the colour at the line would draw the next line |
| 21 | // as code the interpreter will never run as code. |
| 22 | // |
| 23 | // A character literal is read the same way, by the same loop in lexer.go, so |
| 24 | // it is carried the same way. That a 'character' spanning lines is nonsense to |
| 25 | // a reader is beside the point: the colour says what the interpreter will do. |
| 26 | func takeQuoted(s *syntax.LineScanner, quote rune, class syntax.Class, ifOpen carry) carry { |
| 27 | start := s.Pos() |
| 28 | s.Advance(1) // the opening quote |
| 29 | |
| 30 | closed := consumeQuoted(s, quote) |
| 31 | s.Emit(start, s.Pos(), class) |
| 32 | return stillOpen(closed, ifOpen) |
| 33 | } |
| 34 | |
| 35 | // finishQuoted colours the rest of a literal opened on an earlier line, and |
| 36 | // says whether it is still open at the end of this one. |
| 37 | func finishQuoted(s *syntax.LineScanner, quote rune, class syntax.Class, ifOpen carry) carry { |
| 38 | closed := consumeQuoted(s, quote) |
| 39 | s.Emit(0, s.Pos(), class) |
| 40 | return stillOpen(closed, ifOpen) |
| 41 | } |
| 42 | |
| 43 | // consumeQuoted runs to the closing quote, or to the end of the line, and |
| 44 | // reports which it found. |
| 45 | // |
| 46 | // A backslash takes the rune after it out of consideration. That one rule |
| 47 | // covers every escape the lexer knows — \n, \t, \r, \\, \", \', \0 and \xHH — |
| 48 | // and the ones it does not, which it keeps as the character itself; all any of |
| 49 | // them need from this scanner is that the rune after the backslash cannot |
| 50 | // close the literal. A backslash that ends the line escapes the newline, which |
| 51 | // the lexer also reads as part of the string, and the carry covers that. |
| 52 | func consumeQuoted(s *syntax.LineScanner, quote rune) bool { |
| 53 | for !s.AtEnd() { |
| 54 | switch s.Peek(0) { |
| 55 | case '\\': |
| 56 | s.Advance(2) |
| 57 | case quote: |
| 58 | s.Advance(1) |
| 59 | return true |
| 60 | default: |
| 61 | s.Advance(1) |
| 62 | } |
| 63 | } |
| 64 | return false |
| 65 | } |
| 66 | |
| 67 | // takeMultilineString colours a """…""" literal from its opening quotes to its |
| 68 | // closing ones, and reports it as still open when the line ends first. |
| 69 | // |
| 70 | // syntax.OpenBlockComment is named for comments, and what it does is exactly |
| 71 | // this: from an opener to the first closer, or to the end of the line, in one |
| 72 | // class, with no escapes considered. A multi-line string in Golo has no |
| 73 | // escapes either — the lexer appends every rune it meets until the three |
| 74 | // quotes — so the helper is the right tool under a misleading name, and the |
| 75 | // continuation on later lines goes through FinishBlockComment for the same |
| 76 | // reason. |
| 77 | func takeMultilineString(s *syntax.LineScanner) carry { |
| 78 | closed := syntax.OpenBlockComment(s, multilineStringQuote, multilineStringQuote, syntax.ClassString) |
| 79 | return stillOpen(closed, multilineStringOpen) |
| 80 | } |