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).
63 lines
1.9 KiB
Plaintext
63 lines
1.9 KiB
Plaintext
// M1.2 A.1 follow-up — pass-by-value struct args/returns in
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// sx-defined `#objc_class` methods.
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//
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// Wires the new `{Name=field0field1...}` arm of
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// `appendObjcEncoding` into `class_addMethod` registration. Without
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// it, methods that take or return a value-type struct (CGPoint,
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// CGSize, NSRange shapes) used to fail signature-encoding
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// derivation with a "type kind not yet supported" diagnostic.
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//
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// Each sx-defined method registered with the Obj-C runtime needs an
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// encoding string built from its IR signature. For
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// `goto :: (self: *Self, p: Point)` that string is `v@:{Point=dd}`
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// — return void, receiver `@`, selector `:`, then the struct
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// argument `{Point=dd}`.
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//
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// We don't observe the encoding string directly here (it ends up in
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// a private OBJC_METH_VAR_TYPE_ cstring in the linked binary) — but
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// the compiler bails LOUDLY on unsupported types per the project's
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// REJECTED PATTERNS rule, so a successful build is the encoding
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// going through cleanly.
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#import "modules/std.sx";
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#import "modules/compiler.sx";
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#import "modules/std/objc.sx";
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Point :: struct {
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x: f64;
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y: f64;
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}
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SxMover :: #objc_class("SxMover") {
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pos: Point;
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alloc :: () -> *SxMover;
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goto :: (self: *Self, p: Point) {
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self.pos = p;
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}
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here :: (self: *Self) -> Point {
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return self.pos;
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}
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}
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main :: () -> s32 {
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inline if OS == .macos {
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m := SxMover.alloc();
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if m == null { print("FAIL: alloc returned null\n"); return 1; }
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m.goto(Point.{ x = 7.5, y = 8.25 });
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p := m.here();
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print("at: ({}, {})\n", p.x, p.y); // expected: at: (7.500000, 8.250000)
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sel_release : SEL = sel_registerName("release".ptr);
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release_fn : (obj: *void, sel: *void) -> void callconv(.c) = xx objc_msgSend;
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release_fn(xx m, sel_release);
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}
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inline if OS != .macos {
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print("at: (7.500000, 8.250000)\n");
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}
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0
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}
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