Skip to content

Document PRs #98 and #99 in v0.10.0 changelog #100

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
msaelices merged 1 commit into from
Apr 11, 2026
Merged

Document PRs #98 and #99 in v0.10.0 changelog #100

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
8 changes: 8 additions & 0 deletions CHANGELOG.md
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -4,6 +4,14 @@

Performance tuning release. Mojo vs Rust win rate improved from 57% to 64%.

### `StringSlice` pattern in the public API (PRs #98, #99)

- **`compile_regex`, `match_first`, `search`, `findall` now take `pattern: ImmSlice`** instead of `String`, matching the `text: ImmSlice` signatures from PR #95. Callers passing a string literal or existing slice no longer allocate a `String` to probe the regex cache.
- **Hash-keyed regex cache**: cache type is now `Dict[UInt64, CompiledRegex]` keyed on `hash(pattern)`. Cache hits hash the slice, probe the dict, verify `cached.pattern == pattern` byte-for-byte, and return. Zero `String` allocations on the hit path. On a miss, the `String` is allocated once when constructing `CompiledRegex` (which owns `pattern: String` for `get_stats` and engine init). The byte-compare on hit defends against the astronomically rare (`P ~ 10⁻¹⁶` for realistic cache sizes) 64-bit hash collision by falling through to a fresh compile.
- **`NFAMatcher` lazy DFA allocation fix (PR #98)**: `__init__` and `__copyinit__` now use `init_pointee_move` instead of `self._lazy_dfa_ptr[] = LazyDFA(...)`. The old form ran a move-assignment into uninitialized storage returned by `alloc`, destructing garbage memory and causing a nondeterministic crash at process exit. Collapsed the `(ptr, _has_lazy_dfa: Bool)` pair into a single nullable `_lazy_dfa_ptr` to avoid a dead-store warning that masked the real issue.
- **`@always_inline` on `is_match` trampoline**: `CompiledRegex` -> `HybridMatcher` -> `DFAMatcher` -> `DFAEngine` is now inlined end-to-end, so passing a 16-byte `ImmSlice` through four call levels folds into the single-byte-read fast path.
- **Debug info on CI test task (PR #98)**: switched `pixi run test` from `mojo run` to `mojo build -debug-level=line-tables` + execute, so future crashes come with a symbolicated stack trace instead of an unmapped address.

### `StringSlice` in the matcher chain (PR #95)

- **No more `String` allocation at the call site**: `match_first`, `search`,
Expand Down
Loading