build(deps): bump fancy-regex from 0.19.0 to 0.19.1

[dependabot]

Bumps fancy-regex from 0.19.0 to 0.19.1.

Release notes

Sourced from fancy-regex's releases.

0.19.1

Added

• Add a perf-dfa-full feature (off by default, mirroring the regex crate) that lets regex-automata eagerly build fully compiled dense DFAs for small patterns, for workloads that compile few regexes and match them very heavily (#272)

Changed

• Add VM instruction for case insensitive literals when in Unicode mode, to keep the build cost bounded (#268) and ensured the toy example graph output remains readable instead of being super verbose (#269)
• Compilation performance: the regex-automata dependency no longer enables the dfa-build feature by default. With dfa-build enabled, meta::Regex eagerly determinizes a full dense DFA for every small pattern, which dominated build time of simple class-containing patterns (e.g. \b(extern)\s+(crate) compiled ~4x slower than with the regex crate, which also ships without dfa-build); searches use the lazy DFA instead, with no measurable match-time difference (#272)
• Compilation performance: identical delegated fragments within one compile now share a single regex-automata engine instead of each building their own. Alternation-heavy patterns (TextMate grammar lookbehinds especially) often repeat the same fragment many times; on such patterns this removes a large share of build time (#277)

Fixed

• The playground didn't show when a literal or backreference was being matched case insensitively in the analysis tree view (#269)
• Seek patterns could become very large when recursive backrefs and subroutine calls were inlined, without bringing much benefit (#270)
• The optimize_nested_repeats pass could rewrite an optional capture group like (\w+)? into (\w*), causing an unmatched optional group to be reported as an empty match (Some("")) instead of None (#276)

Changelog

Sourced from fancy-regex's changelog.

[0.19.1] - 2026-09-06

Added

• Add a perf-dfa-full feature (off by default, mirroring the regex crate) that lets regex-automata eagerly build fully compiled dense DFAs for small patterns, for workloads that compile few regexes and match them very heavily (#272)

Changed

• Add VM instruction for case insensitive literals when in Unicode mode, to keep the build cost bounded (#268) and ensured the toy example graph output remains readable instead of being super verbose (#269)
• Compilation performance: the regex-automata dependency no longer enables the dfa-build feature by default. With dfa-build enabled, meta::Regex eagerly determinizes a full dense DFA for every small pattern, which dominated build time of simple class-containing patterns (e.g. \b(extern)\s+(crate) compiled ~4x slower than with the regex crate, which also ships without dfa-build); searches use the lazy DFA instead, with no measurable match-time difference (#272)
• Compilation performance: identical delegated fragments within one compile now share a single regex-automata engine instead of each building their own. Alternation-heavy patterns (TextMate grammar lookbehinds especially) often repeat the same fragment many times; on such patterns this removes a large share of build time (#277)

Fixed

• The playground didn't show when a literal or backreference was being matched case insensitively in the analysis tree view (#269)
• Seek patterns could become very large when recursive backrefs and subroutine calls were inlined, without bringing much benefit (#270)
• The optimize_nested_repeats pass could rewrite an optional capture group like (\w+)? into (\w*), causing an unmatched optional group to be reported as an empty match (Some("")) instead of None (#276)

Commits

• 255e05c Version 0.19.1
• 4be1e71 Merge pull request #277 from fancy-regex/memoize
• 405d09d Memoize delegated engine builds within a compile
• de46792 Merge pull request #276 from fancy-regex/fix_nested_repeat_optimization
• 112457c fix for --no-default-features
• c22b2bd optimize: downgrade trailing * to ? when no backreferences are used
• 9051bf7 fix optimize_nested_repeats with optional capture groups
• 415eaab Merge pull request #272 from fancy-regex/perf-dfa
• 88a200c Remove misleading TODO style comment
• e614928 Add perf-dfa-full opt-in feature for eager dense DFA builds
• Additional commits viewable in compare view

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