Fast(er) regular expression engines in Ruby

https://serpapi.com/blog/faster-regular-expression-engines-in-ruby/

60•davidsojevic•1y ago

Comments

yxhuvud•1y ago

Eww, pretending to support utf8 matchers while not supporting them at all was not pretty to see.

gitroom•1y ago

Honestly that part bugs me, fake support is worse than no support imo

kayodelycaon•1y ago

> Another nuance was found in ruby, which cannot scan the haystack with invalid UTF-8 byte sequences.

This is extremely basic ruby: UTF-8 encoded strings must be valid UTF-8. This is not unique to ruby. If I recall correctly, python 3 does the same thing.

    2.7.1 :001 > haystack = "\xfc\xa1\xa1\xa1\xa1\xa1abc"
    2.7.1 :003 > haystack.force_encoding "ASCII-8BIT"
    => "\xFC\xA1\xA1\xA1\xA1\xA1abc" 
    2.7.1 :004 > haystack.scan(/.+/)
    => ["\xFC\xA1\xA1\xA1\xA1\xA1abc"]

This person is a senior engineer on their Team page. All they had to do was google "ArgumentError: invalid byte sequence in UTF-8". Or ask a coworker... the company has Ruby on Rails applications. headdesk

burntsushi•1y ago

The nuance is specifically relevant here because neither of the other two regex engines benchmarked have this requirement. It's doubly relevant because that means running a regex search doesn't require a UTF-8 validation step, and is therefore likely beneficial from a perf perspective, dependening on the workload.

kayodelycaon•1y ago

That’s a good point. I hadn’t considered it because I’ve hit the validation error long before getting to search. It is possible to avoid string operations with careful coding prior to the search.

Edit: After a little testing, the strings can be read from and written to files without triggering validation. Presumably this applies to sockets as well.

DmitryOlshansky•1y ago

I wonder how std.regex of dlang would fare in such test. Sadly due to a tiny bit of D’s GC use it’s hard to provide as a library for other languages. If there is an interest I might take it through the tests.

Watch Los Angeles get built, one building at a time (1880–2026)

Finding a bug in Dummit and Foote's Abstract Algebra

WeatherNext 3

Trusting-Trust Attack against an Entire Linux Distribution

Scientists observe Einstein's gravity in the quantum world

Macbeth and His Problems

Methods for Random Gradients (2024)

Decoding the NEC V20 Microcode

Simple Is Not Small

Caltech Mathathon – first hackathon ever devoted to research level mathematics

Decapitating a MacBook (2025)

The Dataflow Model Revisited

216M Spy TVs – The LG Smart TV Problem [video]

Icy Moons Are Ocean Worlds

bzip3

Replaceable but Employed: Automation and the Meaning of Work

This Month in Ladybird – August 2026

Academia as a d-index measuring contest

Keep Our Servers Running

Show HN: HomeCat – Design your backyard office

My practical approach to surfing the web safely

Whistle Synth Mac App

Schemy Lisp En DOS

How to bring up the Linux Kernel on a new platform

She Also Found It at the Movies

Live map of public transport in Belgium

Rebuilding a 1995 GPS Time Server so I don't get Telstra'd

Bill Gates tries to install MovieMaker (2003)

Catching Crumbs from the Table (2000)

Show HN: Wg-admin – web UI for an existing WireGuard host