bdd0e96d78
A block's value is now its last statement ONLY when that statement is a trailing expression with no `;`. A trailing `;` discards the value, leaving the block void. This makes value-vs-statement explicit and lets the compiler reject "this block was supposed to produce a value". Compiler: - Parser records `Block.produces_value` (last stmt is a no-`;` trailing expression) + `Block.discarded_semi` (the `;` that discarded a value), via `expectSemicolonAfter`. A trailing expression before `}` may now omit its `;` (previously a parse error). Match-arm and else-arm bodies are built value-producing regardless of the arm `;` (arms are exempt — the `;` is an arm terminator). - Lowering: `lowerBlockValue` / the block-expr path / `inferExprType` respect `produces_value`. A value-position block that discards its value is a hard error (`lowerValueBody` for function bodies; the value-context `.block` path for if/else branches, `catch` bodies, value bindings, match arms). Pure-failable `-> !` bodies (value rides the error channel) and a value-if whose branches are void are handled without false errors. - `defer`/`onfail` cleanup bodies lower as statements (void), so a trailing `;` there is fine. Migration (behavior-preserving — output unchanged): - stdlib + ~210 examples: dropped the trailing `;` on value-position last expressions. `format` now ends with an explicit `#insert "return result;"` (it relied on `#insert`-as-block-value, which `;` discards). - Two `main :: () -> s32` examples that relied on the old silent default-return got an explicit trailing `0`. - Rejection snapshots 0412 / 1013 regenerated (their quoted source lines lost a `;`); the diagnostics themselves are unchanged. Docs/tests: specs.md "Block values" section; examples 0040 (rules) + 0041 (rejection); 3 parser unit tests. Filed issue 0066 (pre-existing match-arm negated-literal phi-width quirk, surfaced not caused here). Gates: zig build, zig build test, run_examples.sh -> 343 passed, cross_compile.sh -> 7 passed (also refreshed its stale example names).
37 lines
995 B
Plaintext
37 lines
995 B
Plaintext
#import "modules/std.sx";
|
|
#import "modules/math/math.sx";
|
|
#import "modules/compiler.sx";
|
|
#import "modules/test.sx";
|
|
pkg :: #import "modules/testpkg";
|
|
|
|
add :: (a: s32, b: s32) -> s32 { a + b }
|
|
|
|
main :: () {
|
|
|
|
// ── Trailing commas ──────────────────────────────────────────
|
|
print("=== Trailing Commas ===\n");
|
|
{
|
|
// Struct literal with trailing comma
|
|
Vec4 :: struct { x: f64; y: f64; z: f64; w: f64; }
|
|
v := Vec4.{
|
|
x = 1.0,
|
|
y = 2.0,
|
|
z = 3.0,
|
|
w = 4.0,
|
|
};
|
|
assert(v.x == 1.0);
|
|
assert(v.w == 4.0);
|
|
|
|
// Function call with trailing comma
|
|
add :: (a: s64, b: s64) -> s64 { return a + b; }
|
|
r := add(10, 20,);
|
|
assert(r == 30);
|
|
|
|
// Array literal with trailing comma
|
|
arr := s64.[1, 2, 3,];
|
|
assert(arr[2] == 3);
|
|
|
|
print("trailing commas ok\n");
|
|
}
|
|
}
|