Files
sx/examples/1417-ffi-jni-class-07-all-runtimes.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

48 lines
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// Phase 2 step 2.7 (PLAN-FFI.md): xfail then green for the remaining
// six type-introducer directive forms parsing with the same body
// grammar as `#jni_class`. No codegen yet — Phase 3 picks up Obj-C
// codegen, Phase 4 picks up Swift.
//
// The directives this step turns on:
// #jni_interface — Java interface binding
// #objc_class — Obj-C class binding
// #objc_protocol — Obj-C protocol binding
// #swift_class — Swift class binding (via @_cdecl bridge)
// #swift_struct — Swift @frozen value-type binding
// #swift_protocol — Swift @objc-bridgeable protocol binding
//
// Internally the AST collapses into one `foreign_class_decl` node
// carrying a `runtime` discriminator. Today the parser rejects each
// of these because the lexer doesn't recognise the directive name.
#import "modules/std.sx";
IFoo :: #foreign #jni_interface("com/example/IFoo") {
bar :: (self: *Self) -> s32;
}
NSString :: #foreign #objc_class("NSString") {
length :: (self: *Self) -> s32;
}
NSCopying :: #foreign #objc_protocol("NSCopying") {
copy :: (self: *Self) -> *Self;
}
URL :: #foreign #swift_class("Foundation.URL") {
absoluteString :: (self: *Self) -> *void;
}
Date :: #foreign #swift_struct("Foundation.Date") {
timeIntervalSince1970 :: (self: *Self) -> f64;
}
Hashable :: #foreign #swift_protocol("Swift.Hashable") {
hash :: (self: *Self) -> s32;
}
main :: () -> s32 {
print("parse-only ok\n");
0
}