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module main

// ---------------------------------------------------------------------------
// C-ABI surface consumed by Dart FFI.
//
// Rules for everything below:
//   * only C-compatible types cross the boundary (int, f64, &char, voidptr)
//   * V strings/arrays/options/sumtypes never cross; convert first
//   * anything V allocates and hands out is released by vf_free
// ---------------------------------------------------------------------------

// Touches the V runtime so the GC and global initialisers are demonstrably
// live. The ELF/Mach-O constructor emitted by `v -shared` already does this;
// this exists for static-archive builds (iOS) where the caller wants a
// guaranteed, idempotent entry point.
@[export: 'vf_init']
fn vf_init() {
	probe := 'vf'
	_ = probe.len
}

@[export: 'vf_add']
fn vf_add(a int, b int) int {
	return a + b
}

// Returns a V-allocated C string. Caller releases it with vf_free.
//
// Built with `-gc none`, so every intermediate V allocation here must be
// freed by hand. Only the returned buffer outlives the call.
@[export: 'vf_greet']
fn vf_greet(name &char) &char {
	n := unsafe { cstring_to_vstring(name) }
	res := 'Hello, ${n}, from V!'
	out := unsafe { res.str }
	unsafe { n.free() }
	return out
}

@[export: 'vf_free']
fn vf_free(p voidptr) {
	unsafe { free(p) }
}