ref/hare/strings/replace.ha:46-66. Two-pass byte scan: pass 1 counts
non-overlapping needle hits via bytes.hasprefix, pass 2 allocs the
result []u8 at exact size and copies chunks + replacement. Single
nomem propagation site at the alloc — ww's append builtin aborts
on OOM (#11), so the per-chunk append(...)? form Hare uses is not
available; the exact-size single alloc is equivalent in spec.
total==0 returns {nil,0} to dodge rt_alloc(0) per #47.
Empty needle is intentionally ungated and loops forever — that's
Hare's behavior at ref/hare/strings/replace.ha:31 (i += len(needle)
is 0; hasprefix("") always matches). Hare-faithful divergence,
documented at the site.
multireplace deferred to #49 — its (str, str) variadic gather hits
#39 in variadic-param position. Filed and blocked accordingly.
Hojun-Cho
cd44cc1893