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
1.2 KiB
Plaintext
32 lines
1.2 KiB
Plaintext
// Slice-of-protocol variadic `..xs: []P` — the RUNTIME counterpart to the
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// comptime pack `..xs: P`. Each trailing arg is `xx`-erased to a `P` protocol
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// value {ctx, vtable} and packed into a runtime `[]P`, so the elements can be
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// indexed by a RUNTIME index and dispatched through the protocol interface
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// (unlike a pack, which is comptime-only — see examples/163).
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//
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// This is the type-safe way to iterate a heterogeneous arg list at runtime:
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// concrete per-position types are erased to the constraint protocol.
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#import "modules/std.sx";
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Show :: protocol { show :: (self: *Self) -> string; }
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A :: struct { x: i64; }
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B :: struct { s: string; }
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impl Show for A { show :: (self: *A) -> string => "A"; }
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impl Show for B { show :: (self: *B) -> string => "B"; }
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// Runtime loop over a []Show: runtime index + protocol-method dispatch.
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each :: (..xs: []Show) -> void {
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i := 0;
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while i < xs.len {
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print("[{}]={}\n", i, xs[i].show());
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i = i + 1;
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}
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}
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main :: () -> i32 {
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each(A.{ x = 1 }, B.{ s = "hi" }, A.{ x = 3 }); // heterogeneous, erased to Show
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each(); // empty is fine (len 0)
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0
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}
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