Files
sx/examples/1335-ffi-objc-call-09-in-construct.sx
agra bdd0e96d78 feat(lang): block value requires no trailing ; (Rust-style)
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).
2026-06-02 09:23:50 +03:00

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// Phase 1 steps 1.111.13 (PLAN-FFI.md): `#objc_call` call sites
// embedded inside the sx surface constructs. None touch a new ABI
// path — the lowering routes the call identically regardless of
// the enclosing scope, and this test pins that lemma.
//
// 1. Struct method body Probe.fetch
// 2. Protocol impl method body impl Hashable for Probe
// 3. Closure value body closure that calls hash
//
// 1.14 (separate test): `inline if OS == { case }` gating across
// targets — verified by `tests/cross_compile.sh`.
#import "modules/std.sx";
#import "modules/compiler.sx";
#import "modules/std/objc.sx";
// ── 1. Struct method calling #objc_call ─────────────────────────────
Probe :: struct {
receiver: *void = null;
fetch :: (self: *Probe) -> s64 {
#objc_call(s64)(self.receiver, "hash")
}
}
// ── 2. Protocol impl method ────────────────────────────────────────
Hashable :: protocol {
sx_hash :: (self: *Self) -> s64;
}
impl Hashable for Probe {
sx_hash :: (self: *Probe) -> s64 {
#objc_call(s64)(self.receiver, "hash") * 2
}
}
// ── 3. Closure body invoking #objc_call ─────────────────────────────
// The closure captures `recv` from its enclosing function and
// references it inside the `#objc_call` arg list. Locked in by
// `examples/103-ffi-closure-capture.sx`.
make_hasher :: (recv: *void) -> Closure(s32) -> s64 {
closure((dummy: s32) -> s64 => #objc_call(s64)(recv, "hash"))
}
// ── 4. Generic function body — instantiated per call site ───────────
hash_through :: (recv: $T) -> s64 {
p : *void = xx recv;
#objc_call(s64)(p, "hash")
}
main :: () -> s32 {
inline if OS == .macos {
ns_object := objc_getClass("NSObject".ptr);
p : Probe = .{ receiver = ns_object };
// 1. struct method
h1 := p.fetch();
print("fetch != 0 = {}\n", h1 != 0);
// 2. protocol method (doubles the raw hash; mostly checking
// dispatch / arg threading, not the math)
h2 := p.sx_hash();
print("protocol h2 = {}\n", h2 == h1 * 2);
// 3. closure (receives a dummy arg to keep the `Closure(T) -> R`
// arity matching 35-closures.sx; `recv` is captured from
// `make_hasher`'s arg list and used inside the `#objc_call`).
hasher := make_hasher(ns_object);
h3 := hasher(0);
print("closure h3 = {}\n", h3 == h1);
// 4. generic function — instantiates with T = *void here
h4 := hash_through(ns_object);
print("generic h4 = {}\n", h4 == h1);
}
inline if OS != .macos {
print("skipped (not macos)\n");
}
0
}