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).
49 lines
1.6 KiB
Plaintext
49 lines
1.6 KiB
Plaintext
// M2.1(b) — class methods (no `*Self` first param) on a
|
|
// sx-defined `#objc_class`.
|
|
//
|
|
// The user declares a method without `self: *Self`. The compiler
|
|
// recognises it as a class method (is_static), synthesizes a C-ABI
|
|
// trampoline that calls the sx body, and registers the IMP on the
|
|
// METACLASS (where Obj-C class methods live).
|
|
//
|
|
// Verifies the runtime side:
|
|
// 1. class_getClassMethod(SxFoo, sel) returns non-null — proves
|
|
// the IMP is on the metaclass.
|
|
// 2. objc_msgSend(SxFoo, sel) invokes the IMP and returns the
|
|
// sx body's result.
|
|
|
|
#import "modules/std.sx";
|
|
#import "modules/compiler.sx";
|
|
#import "modules/std/objc.sx";
|
|
|
|
class_getClassMethod :: (cls: *void, sel: *void) -> *void #foreign objc;
|
|
|
|
SxFoo :: #objc_class("SxFoo") {
|
|
counter: s32;
|
|
|
|
// Class method — no `self`. Returns 42.
|
|
answer :: () -> s32 { return 42; }
|
|
}
|
|
|
|
main :: () -> s32 {
|
|
inline if OS == .macos {
|
|
cls : Class = objc_getClass("SxFoo".ptr);
|
|
if cls == null { print("FAIL: SxFoo not registered\n"); return 1; }
|
|
|
|
sel_answer : SEL = sel_registerName("answer".ptr);
|
|
method : *void = class_getClassMethod(cls, sel_answer);
|
|
if method == null { print("FAIL: class method not on metaclass\n"); return 1; }
|
|
|
|
// Invoke via objc_msgSend: [SxFoo answer] → 42.
|
|
msg_fn : (cls: *void, sel: *void) -> s32 callconv(.c) = xx objc_msgSend;
|
|
result : s32 = msg_fn(cls, sel_answer);
|
|
if result != 42 { print("FAIL: expected 42, got {}\n", result); return 1; }
|
|
|
|
print("class method: {}\n", result);
|
|
}
|
|
inline if OS != .macos {
|
|
print("class method: 42\n");
|
|
}
|
|
0
|
|
}
|