feat(typeck): support negative integer literal coercion #648
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This enables distinguishing edge cases like 127 (fits in int8) from 128 (doesn't fit), which is needed for correct implicit and explicit integer conversions. - Changed internal storage from `u8` (bytes 0-32) to `u16` (bits 0-256) - `TypeSize::new()` now takes bits directly - Added `new_fb_bytes()` for fixed-bytes types that take byte counts - `bits()` returns stored value, `bytes()` computes `ceil(bits/8)` - `mk_ty_int_literal` no longer rounds to multiples of 8 Closes #650 Unblocks #647 #648 #649
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Add implicit type coercion for integer literals (IntLiteral) to typed integers (uint/int). The coercion rules are: - IntLiteral -> uint: Allowed if the literal is non-negative and fits in the target size (size.bits() <= target.bits()) - IntLiteral -> int: Allowed with strict inequality (size.bits() < target.bits()) for non-negative values due to TypeSize rounding, and non-strict for negative values TypeSize stores ceil(bit_len/8), so int_literal[1] covers 0-255. This means we can't distinguish edge cases like 127 (fits in int8) from 128 (doesn't fit), so we conservatively require int16+ for int_literal[1]. Note: Negative literal support requires additional work in the type checker to propagate negativity through unary negation. This is provided in a follow up. Supercedes #564 and closes #627 (closes #564) Stack: - #647 (this) - #648 - #649
Implement proper handling of negative integer literals in the type checker. Previously, negative literals like -42 were broken because: 1. The parser represents them as unary negation applied to a positive literal, so type_of_lit only sees the positive value 2. The negativity flag in IntLiteral was always false This commit fixes the issue by: - Allowing unary negation on IntLiteral types (they can always be negated since the result is just a negative literal) - Propagating the negativity flag when applying unary negation to an IntLiteral, flipping neg from false to true - Not propagating the expected type through negation when targeting signed types, to avoid premature type mismatch errors on the inner expression Also simplifies the coercion rule to use strict inequality for both positive and negative literals, since TypeSize rounding means we can't reliably distinguish edge cases in either direction.
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Implement proper handling of negative integer literals in the type checker. Previously, negative literals like -42 were broken because:
This commit fixes the issue by:
Also simplifies the coercion rule to use strict inequality for both positive and negative literals, since TypeSize rounding means we can't reliably distinguish edge cases in either direction.
On top of #647
Supercedes #566 (will mark @mablr as a co-author to commend effort) and closes #560 (closes #566)
Stack: