Hare's delete also takes a slicing place (harec check.c:1981-2027 EXPR_SLICE; Hare spells it delete(xs[i..j])): remove [lo, hi) — shift [hi..len) down count = hi-lo strides, len -= count, cap unchanged; lo defaults 0, hi defaults len, so delete(xs[:]) clears the slice with storage retained. Checker accepts N_SLICE next to N_INDEX (object must chase to a slice, harec :2024); the old range-unimplemented reject and its #35 cite drop. Lowering (both stages, converged byte-identical by construction) is the single-element arm's same-slice whole-stride word-copy loop with a DYNAMIC src offset (count*esz via a src register) instead of the constant one-stride. Base shapes: local slice ident, deref-of-local, plus NEW indexed local-slice base xs[g][lo:hi] — the fold-5a consumer shape (regex.ha:333 delete(jump_idxs[group_level][..]); outer stride off the type table). Bounds stay implicit, inheriting the documented single-element posture (no index checks anywhere in cgen). Operands evaluate left-to-right, exactly once, before the shift (harec order); only the header ADDRESS is taken before operand eval, so a bound expression's writes through the slice land before the copy. test/809: 64 fixtures — full/explicit/re-clear/head/mid/tail/empty a:a/end-boundary len:len/explicit 0:0 on a never-appended (nil-ptr) slice, single-vs-range equivalence, cap preservation, esz 1/2/4/8/16/24 copy tails against the dynamic src, operand order-of-eval (lo/hi CALLs fire once each, in order) + aliasing-visibility pins, the EXACT [][]size regex consumer shape, deref base, 2 reject rows w/ diagnostic text; every accept row cs==ww asm byte-id. test/804: reject_range row retired (form now accepted), reject_nonindex text follows the widened message.
19 KiB
19 KiB