Regex Performance

The cluster focuses on discussions about the performance of regex engines and libraries across programming languages, including comparisons, optimizations like JIT and DFA compilation, and specific implementations such as Rust's regex, RE2, PCRE, and Hyperscan.

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Keywords

e.g PHP CPU RE2 JIT jarvana.com PR FAQ PCRE PCRE2 regex compile rust library matching expression optimizations engine string performance

Sample Comments

episteme Jul 9, 2022 View on HN

I thought Regex was typically less performant than string operations?

dana321 Nov 29, 2025 View on HN

Imagine hardening the regex library, its already as slow as molasses.

Ygg2 Apr 27, 2014 View on HN

How does this compare to other regex parsing libraries, performance wise?

sitkack Jul 6, 2014 View on HN

Until they implement a JIT and compile the regex.

fortran77 Sep 29, 2019 View on HN

Is the Rust regex engine slow because it's written in Rust?

austincheney Jan 20, 2017 View on HN

Is regex execution considered efficient? I have always been impressed with its speed.

Phelinofist Dec 30, 2023 View on HN

Any experience with performance? This seems to be heavy with regexes

sansnomme Nov 30, 2019 View on HN

What sort of Regex are they using? The garden variety can be compiled to DFAs (O(n)) which a modern computer should have no issues handling. Further optimizations

burntsushi Jan 21, 2017 View on HN

I am responding to your claim. I'm saying that not all regex implementations are created equal. Some can be just as fast as what you might write by hand.

dang Sep 12, 2022 View on HN

Related:Hyperscan: High-performance multiple regex matching library from Intel - https://news.ycombinator.com/item?id=21873557 - Dec 2019 (53 comments)Hyperscan: A Fast Multi-Pattern Regex Matcher for Modern CPUs - https://news.ycombinator.com/item?id=19270199 - Feb 201