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).
42 lines
1.7 KiB
Plaintext
42 lines
1.7 KiB
Plaintext
// Phase 3 step 3.2 (PLAN-FFI.md): `#selector("explicit:string")`
|
|
// override on `#objc_class` members. Escape hatch for cases where the
|
|
// sx-side method name doesn't conveniently produce the target selector
|
|
// through the default mangling rule (Phase 3.0 — split on `_`, each
|
|
// piece becomes a keyword with a trailing `:`).
|
|
//
|
|
// Surface form mirrors `#jni_method_descriptor("(Sig)Ret")` — sits
|
|
// after the optional `-> ReturnType` and before the body / terminator.
|
|
//
|
|
// Pre-3.2: the parser doesn't know the `#selector` token; snapshot
|
|
// captures the parser error (exit=1). Next commit wires lexer + parser
|
|
// + AST + lowering and the snapshot flips to working output.
|
|
#import "modules/std.sx";
|
|
#import "modules/compiler.sx";
|
|
|
|
NSObject :: #foreign #objc_class("NSObject") {
|
|
// Default mangling would yield selector "gimme" — NSObject has no
|
|
// such IMP. The override pins it to the real selector
|
|
// "description". Static method (no `self: *Self` first param).
|
|
gimme :: () -> *void #selector("description");
|
|
}
|
|
|
|
// Instance-method override exercises a different lowering path
|
|
// (`lowerObjcMethodCall` rather than `lowerObjcStaticCall`). Parse-
|
|
// only on this side — main only invokes the static path because we
|
|
// don't have a real NSDictionary in scope, but the declaration locks
|
|
// in the parser + AST + lowering wiring for the multi-arg shape.
|
|
NSDictionary :: #foreign #objc_class("NSDictionary") {
|
|
lookup :: (self: *Self, key: *void) -> *void #selector("objectForKey:");
|
|
}
|
|
|
|
main :: () -> s32 {
|
|
inline if OS == .macos {
|
|
d := NSObject.gimme();
|
|
print("static override non-null: {}\n", d != null);
|
|
}
|
|
inline if OS != .macos {
|
|
print("skipped (not macos)\n");
|
|
}
|
|
0
|
|
}
|