Files
sx/examples/0401-protocols-protocol-in-wrapper-struct.sx
agra d8076b9333 lang: rename signed integer types sN -> iN
Surface rename of the signed integer family: s1..s64 become i1..i64
(u1..u64, usize, isize unchanged). 'string' keeps the s-prefix arm in
name classification; width parsing moves to the i-prefix arm next to
isize.

Internal TypeId tags follow the surface (.s8/.s16/.s32/.s64 ->
.i8/.i16/.i32/.i64), as do mono-key mangle fragments (ptr_i64,
tu_i64_bool) and all display/diagnostic formatting (i{d}).

Migrated in the same sweep: stdlib + examples + issue repros + FFI C
companions (shared symbol names like ffi_id_i64), expected
stdout/stderr/ir snapshots, specs.md, readme.md, CLAUDE.md/AGENTS.md,
implementation_plan.md, docs/, issue writeups. Vendored stb_image and
historical flow state left untouched.

zig build test: 426/426; examples suite: 595/595.
2026-06-12 09:31:53 +03:00

49 lines
1.4 KiB
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// Protocol value as a field of a wrapper struct, constructed from a stack
// local inside a function and appended to a `List`. The payload must be
// heap-copied so dispatch survives the constructing function returning.
#import "modules/std.sx";
Sizable :: protocol {
size :: () -> i64;
}
Widget :: struct { value: i64; }
impl Sizable for Widget {
size :: (self: *Widget) -> i64 { self.value }
}
// Wrapper struct with a protocol field (like ViewChild)
Item :: struct {
view: Sizable;
}
Container :: struct {
items: List(Item);
add :: (self: *Container, w: Widget) {
p := w; // local copy
self.items.append(Item.{ view = p }); // protocol created from stack local `p`
// Works here: stack local `p` is still alive
out("inside add: ");
print("{}\n", self.items.items[self.items.len - 1].view.size());
}
}
main :: () -> void {
c : Container = .{};
c.add(Widget.{ value = 42 });
c.add(Widget.{ value = 99 });
// BUG: items[0] should return 42, but returns 99 (reads items[1]'s stack slot)
// Both protocol values point to the same stack address (the `p` local in add())
r0 := c.items.items[0].view.size();
r1 := c.items.items[1].view.size();
print("items[0] = {} (expected 42)\n", r0);
print("items[1] = {} (expected 99)\n", r1);
// With more stack activity between add() and the reads, this crashes
// (stack memory overwritten by other function calls)
}