moonbitlang / core / 4144

94%

push

github

refactor(builtin): declarative for-in with carry-state in Array::retain

Replace `for i = 0, j = 0; i < len; { ... continue i+1, j+1 / continue i+1, j }`
with `for v in self; j = 0 { ... continue j+1 / continue j }`. The iterator
covers `i`; only the write index needs carrying, expressed with `;` carry-state.
Also drop the redundant `// we use else here to capture j` comment — the
`nobreak` clause makes the binding visible without explanation.

Semantics-preserving: `moon test -p builtin` (2825/2825) passes and
`moon info` produces no `.mbti` change.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

3 of 3 new or added lines in 1 file covered. (100.0%)

14884 of 15742 relevant lines covered (94.55%)

217986.45 hits per line