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regress

0.12.045M downloads/moridiculousfish/regress ↗New releases in your daily digest, changelog included.

A regular expression engine targeting EcmaScript syntax

Last release 1 months ago
23 Aug 2026
Ships fairly regularly
a new release about every 3 months
Some releases are documented
notes for 9 of 25 stable releases
Nothing withdrawn
no release was ever pulled
6 years old
25 releases · first in 2020

Release timeline

25 releases since 2020

2020202120222023202420252026

20202026

One column per quarter.

Releases

0.12.023 Aug 2026
Restored support for no_std + alloc builds. Use: --no-default-features --features alloc .
Highlights

Restored support for no_std + alloc builds. Use: --no-default-features --features alloc.

Added Unicode Script=Unknown property support.

Improved correctness for ECMAScript Unicode Sets (v mode), inline modifier groups, and several Unicode case-insensitive matching cases.

Hardened parsing against excessively nested expressions, avoiding stack-overflow failures.

Reduced downstream binary size by avoiding forced inlining of regex construction and search internals.

Fixes

Correctly propagate flags from inline modifier groups.

Correct handling of nested and negated character sets in v mode.

Correct parsing of invalid \x escapes as identity escapes where ECMAScript permits it.

Correctly detect start-anchored alternations.

Include the v flag in Flags formatting.

Make Regex::find_from clearly panic when given an index that splits a UTF-8 code point.

Fix big-endian matching.

Avoid overly aggressive loop unrolling.

Performance and implementation

Improve PikeVM handling of one-character loops and reduce state allocation overhead.

Improve Unicode string-set lowering and longest-match ordering.

Improve case-folding/literal lowering internals.

Add a safety limit for deeply nested patterns.

Allow downstream users to share regex internals rather than duplicating them through inlining.
Open source →

Fix incorrectly faililng to match with certain long literal sequences within lookbehind assertions

Fixed

Fix incorrectly faililng to match with certain long literal sequences within lookbehind assertions

New Contributors

@sadan4 made their first contribution in #145

Full Changelog: v0.11.0...v0.11.1

Open source →

0.11.010 Mar 2026

This release adds support for duplicate named capture groups and includes a set of correctness fixes around Unicode case folding, word-character handl

v0.11.0

This release adds support for duplicate named capture groups and includes a set of correctness fixes around Unicode case folding, word-character handling, and capture-group indexing. Unicode data has also been updated to Unicode 17.

Added

Implement TC39 duplicate named capturing groups support, allowing the same group name in disjoint alternations.
Update Unicode data tables to Unicode 17.

Fixed

Fix incorrect ASCII executor behavior when Unicode mode and case-insensitive matching were combined.
Fix Unicode case-insensitive word-character handling for characters such as U+212A and U+017F (in fact the only such characters).
Fix a panic for character classes for certain script extensions

New Contributors

@n-faria made their first contribution in #136

Full Changelog: v0.10.4...v0.11.0

Open source →

0.10.530 Oct 2025

impl Modifier by @asukaminato0721 in #133

What's Changed

impl Modifier by @asukaminato0721 in #133
Update hashbrown requirement from 0.15.0 to 0.16.0
Fixes a bug where a branch that could never match would incorrectly number capture groups #131
Fixes a bug where certain non-greedy loops over empty capture groups might loop infinitely #131
Various performance optimizations

Full Changelog: v0.10.4...v0.10.5

Open source →

0.10.413 Jul 2025

Welcome new committer @asukaminato0721

What's Changed

Welcome new committer @asukaminato0721

Escape literals by @asukaminato0721 in #104
Pattern support on nightly by @asukaminato0721 in #102

Full Changelog: v0.10.3...v0.10.4

Open source →

0.10.321 Jan 2025

Fix a panic for certain regular expressions when matching in UTF-16 or UCS-2 mode #101

What's changed

Fix a panic for certain regular expressions when matching in UTF-16 or UCS-2 mode #101
Fixed incorrect matches in UTF-16 or UCS-2 mode and improved test coverage

Open source →

0.10.212 Jan 2025

Fix a crash with empty brackets like /[]*/ in #99

What's Changed

Fix a crash with empty brackets like /[]*/ in #99
Fix a false positive match for ASCII brackets against certain UTF-16 inputs in #100
Update hashbrown requirement from 0.14.3 to 0.15.0 by @dependabot in #98

Open source →

0.10.12 Sept 2024

Nothing published for this version

0.10.029 May 2024

Version 0.10.0 of regress, REGex in Rust with EmcaScript Syntax.

Update unicode to 15.1.0 (#94)

Full Changelog: v0.9.1...v0.10.0

Open source →

0.9.12 Apr 2024

Version 0.9.1 of regress, REGex in Rust with EmcaScript Syntax.

Fix UTF-16 next position methods (#93)

Full Changelog: v0.9.0...v0.9.1

Open source →

0.9.026 Feb 2024

Nothing published for this version

0.8.029 Jan 2024

Nothing published for this version

0.7.125 Aug 2023

Nothing published for this version

0.7.025 Aug 2023

Nothing published for this version

0.6.028 Apr 2023

Nothing published for this version

0.5.013 Mar 2023

Nothing published for this version

0.4.19 Jul 2021

Nothing published for this version

0.4.09 Jul 2021

Nothing published for this version

0.3.030 May 2021

Nothing published for this version

0.2.021 Oct 2020

Nothing published for this version

0.1.410 Sept 2020

Nothing published for this version

0.1.326 May 2020

Nothing published for this version

0.1.225 May 2020

Nothing published for this version

0.1.125 May 2020

Nothing published for this version

0.1.025 May 2020

Nothing published for this version

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regress

Release timeline

Releases

Highlights

Fixes

Performance and implementation

Fixed

New Contributors

v0.11.0

Added

Fixed

New Contributors

What's Changed

What's Changed

What's changed

What's Changed