fc4d239fdd
Each argument bound to a `..xs: P` pack must conform to P — previously the constraint was decorative (any type was accepted). `lowerPackFnCall` now captures the pack param's constraint protocol and checks each pack arg via a new `packArgConformsTo`, which accepts: a plain-protocol impl (`protocol_thunk_map`), any parameterised impl `P(<args>) for T` (scan of `param_impl_map` for a `P\x00…\x00mangle(T)` key — the per-element type-args are inferred from the impl, not written out), or an arg already erased to P's own protocol struct. Non-conformers get a per-position error pointing at the argument. Only enforced for a known protocol constraint. Regression: examples/192-pack-non-conform.sx (a struct lacking `impl Show` in a `..xs: Show` pack → diagnostic, exit 1).
25 lines
686 B
Plaintext
25 lines
686 B
Plaintext
// Feature 1 — a pack argument that doesn't conform to the constraint protocol
|
|
// is a per-position error. `Naked` has no `impl Show`, so passing it to a
|
|
// `..xs: Show` pack is rejected (pointing at the offending argument).
|
|
|
|
#import "modules/std.sx";
|
|
|
|
Show :: protocol(T: Type) {
|
|
get :: (self: *Self) -> T;
|
|
}
|
|
IntBox :: struct { v: s64; }
|
|
impl Show(s64) for IntBox { get :: (self: *IntBox) -> s64 => self.v; }
|
|
|
|
Naked :: struct { x: s64; } // intentionally NOT `impl Show`
|
|
|
|
howmany :: (..xs: Show) -> s64 {
|
|
return xs.len;
|
|
}
|
|
|
|
main :: () -> s32 {
|
|
a := IntBox.{ v = 1 };
|
|
n := Naked.{ x = 2 };
|
|
print("{}\n", howmany(a, n)); // `n` does not conform to Show
|
|
0;
|
|
}
|