6b0ebdd92b
Protocol method declarations now declare their receiver explicitly as the first parameter — 'self: *Self' (or 'self: Self') — matching the impl method signature, instead of the old implicit-receiver form where the listed params were only the extra args. That asymmetry repeatedly caused confusion over whether the first param was the receiver or an argument. The parser validates the first param is 'self' typed Self/*Self, then strips it, so all downstream lowering and the dispatch ABI are unchanged (impl blocks and call sites are unaffected). A protocol method missing the receiver is now a parse error. Migrated all 129 protocol method signatures across library + examples (+ one inline-sx test in sema.zig) to the explicit form. Updated specs.md + readme.md. New: examples/0418-protocols-explicit-receiver.sx (feature), examples/1190-diagnostics-protocol-missing-receiver.sx (negative/diagnostic).
32 lines
1.1 KiB
Plaintext
32 lines
1.1 KiB
Plaintext
// Feature 1 — protocol-interface method calls on heterogeneous pack elements.
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//
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// `..xs: Greeter` binds per call shape; each `xs[i]` is the concrete element,
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// and calling the protocol's own method `greet()` on it dispatches to that
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// element's impl. Elements may be DIFFERENT concrete types (Dog, Cat) as long
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// as each conforms to Greeter — this is the protocol-interface access the
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// pack is for. (Protocol method decls omit the implicit `self`; impls list it.)
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#import "modules/std.sx";
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Greeter :: protocol {
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greet :: (self: *Self) -> i64;
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}
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Dog :: struct { age: i64; }
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Cat :: struct { lives: i64; }
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impl Greeter for Dog { greet :: (self: *Dog) -> i64 => self.age; }
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impl Greeter for Cat { greet :: (self: *Cat) -> i64 => self.lives * 100; }
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pair_sum :: (..xs: Greeter) -> i64 {
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return xs[0].greet() + xs[1].greet();
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}
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main :: () -> i32 {
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d := Dog.{ age = 3 };
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c := Cat.{ lives = 9 };
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print("dog+cat={}\n", pair_sum(d, c)); // 3 + 900 = 903 (heterogeneous)
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print("cat+dog={}\n", pair_sum(c, d)); // 900 + 3 = 903 (order swapped)
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print("dog+dog={}\n", pair_sum(d, Dog.{ age = 4 })); // 3 + 4 = 7
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0
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}
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