coregex v0.7.0 Released - OnePass DFA for 10x Faster Capture Groups

[kolkov]

coregex v0.7.0 is here!

We are excited to announce coregex v0.7.0 with OnePass DFA optimization for capture group extraction.

What is OnePass DFA?

OnePass DFA is a specialized automaton that can extract capture groups in a single forward pass without backtracking. It works for patterns where at each byte position, there is only one possible transition.

Performance Improvements

Operation	PikeVM	OnePass	Speedup
FindSubmatch	~700 ns	70 ns	10x
IsMatch anchored	~50 ns	27 ns	1.8x
Memory allocations	2-3	0	Zero alloc

Patterns That Benefit

• Date parsing: (\d+)-(\d+)-(\d+)
• Key-value: ([a-z]+)=([^;]+)
• Word pairs: ([a-z]+)\s+([a-z]+)
• Simple alternations: a(b|c)d

How It Works

coregex automatically detects if a pattern is one-pass compatible and uses the optimized engine. No code changes required!

re := coregex.MustCompile(`(\d+)-(\d+)-(\d+)`)
match := re.FindStringSubmatch("2025-11-28")
// Automatically uses OnePass DFA - 10x faster!

Full Release Notes

https://github.com/coregx/coregex/releases/tag/v0.7.0

Installation

go get github.com/coregx/coregex@v0.7.0

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We would love to hear your feedback! Please share your use cases and benchmark results.