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.

Japan develops a method to recover up to 90% of lithium from used EV batteries

Alternative(s) to run CUDA on non-Nvidia hardware

The git history command

Australian energy retailers must provide three hours of free daytime electricity

Indian scientists produce most detailed 3D atlas of the human brainstem

YouTrackDB is a general-use object-oriented graph database

Notable Knot Index (2016)

Building and shipping Mac and iOS apps without opening Xcode

Fundamentals of Wireless Communication (2005)

How to build a circular LCD clock

Just Let Me Write Digits

Understanding the Go Runtime: Profiling

The Economics of Recursive Self-Improvement [pdf]

An Englishwoman who sketched India before photography took hold

Zero Knowledge Tolstoyan Art

Is x86 ready to ACE it?

Satellite Tracker – Live Map of Starlink and 30k Satellites

Your 'App' Could Have Been a Webpage (so I fixed it for you)

World-First 'Super Alloy' Could Transform the Way Metals Are Made

MorphoHDL: A minimalistic language for growing circuits

The infinite scroll may become endangered if controversial Calif. law passes

Writing a bindless GPU abstraction layer

Nokia’s years of mobile-phone supremacy ended in an afternoon

Two Case Studies of NaN

What are Forward Deployed Engineers, and why are they so in demand? (2025)

Jektex 0.2.0 – A Jekyll plugin for LaTeX rendering is now ~10x faster

Linux 0.11 rewritten in idiomatic Rust, boots in QEMU

Linux on the Sega 32X. Who needs hardware synchronization primitives anyway?

Show HN: Clawk – Give coding agents a disposable Linux VM, not your laptop

Precursor