c01ece5483
The count description claimed every count must be "positive integral", which is wrong: zero is context-dependent. Verified at HEAD — an array dimension (`[0]s64`) and a generic value-param count (`Box(0)`, $N:u32) both accept zero as a length-0 instantiation, while a `Vector` lane count stays strictly positive (`Vector(0,f32)` rejected). Negatives are rejected for array dims and unsigned value-params, but a signed value-param accepts a negative; only the integral requirement (folds 4.0, rejects 4.5) is common to all three. Split the count paragraph into per-consumer bullets stating the exact range each accepts. Range-bound paragraph unchanged. Pin the zero contrast with examples 0147 (array-dim + value-param zero accepted) and 1505 (Vector zero-lane rejected). No compiler-code change.
20 lines
739 B
Plaintext
20 lines
739 B
Plaintext
// Zero is a context-dependent count. An array dimension and a generic
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// value-param count both ACCEPT zero — `[0]T` is a valid empty (zero-length)
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// array, and `Box(0)` is a length-0 instantiation. (A `Vector` lane count
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// rejects zero — see 1505.) This pins the zero-accepting half of the
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// context-dependent count rule documented in specs.md (Array Types).
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//
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// Regression (F0.4 attempt 12): the spec previously claimed every count must be
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// "positive integral", which wrongly implied `[0]T` / `Box(0)` are illegal.
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#import "modules/std.sx";
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Box :: struct($N: u32) { items: [N]s64; }
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main :: () {
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a : [0]s64 = ---;
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print("array_dim={}\n", a.len);
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b : Box(0) = ---;
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print("value_param={}\n", b.items.len);
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}
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