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).
43 lines
1.4 KiB
Plaintext
43 lines
1.4 KiB
Plaintext
#import "modules/std.sx";
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#import "modules/math/math.sx";
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#import "modules/compiler.sx";
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#import "modules/test.sx";
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pkg :: #import "modules/testpkg";
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main :: () {
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// --- UFCS Aliases & Pipe ---
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{
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print("=== UFCS Aliases ===\n");
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num_sum :: (a: s64, b: s64) -> s64 { a + b }
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sum :: ufcs num_sum;
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print("{}\n", num_sum(40, 2)); // 42 — direct call
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print("{}\n", sum(40, 2)); // 42 — alias direct call
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print("{}\n", 40 |> sum(2)); // 42 — pipe UFCS via alias
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print("{}\n", num_sum(40, 2)); // 42 — direct (was tuple full-splat)
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print("{}\n", 40 |> sum(2)); // 42 — pipe (was tuple partial-splat)
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compute :: (a: s64, b: s64, c: s64, d: s64) -> s64 { a + b * c - d }
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calc :: ufcs compute;
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print("{}\n", compute(1, 2, 3, 4)); // 1+2*3-4 = 3 (was tuple full-splat)
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print("{}\n", compute(1, 2, 3, 4)); // same = 3 (was tuple partial-splat)
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print("{}\n", 1 |> calc(2, 3, 4)); // same = 3 — pipe UFCS
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// Tuple return type
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swap :: (a: s64, b: s64) -> (s64, s64) { (b, a) }
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s := swap(1, 2);
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a := s.0;
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b := s.1;
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print("{}\n", a); // 2
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print("{}\n", b); // 1
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wrap :: (x: s64) -> (s64) { (x,) }
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t := wrap(99);
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print("{}\n", t.0); // 99
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}
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}
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