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.

Discovery of a new OpenAI agent message board

Solving the Jane Street Reverse Engineering Challenge

GPT-6 Astra

.name Termination

O&O ShutUp10 – The antispy tool for Windows 10 and 11

Elevator of the Year Winner Modernization of the Metropolis Trust Building

SubImage (YC W25) Is Hiring a Founding Engineer in SF

Qwen 3.8 27B available on Cerebras at 1500 tokens/s

Carbon-aware electricity pricing, measured daily on 38 grids

Authorization terminology is a mess: Let's fix it

Hackers Had a Live Feed of Every ID Verification Company Scanned for over a Year

The largest electric aircraft just flew [video]

Artificial beaver dams saw juvenile coho salmon survival rates go from 8% to 60%

How an MIT research project became the Julia programming language

Go grandmaster Shin defeats AI KataGo with a two-stone handicap

Porting my 1993 Amiga game to Godot, with an LLM reading the 68000 assembly

Project Xanadu: Even More Hindsight (2025)

K2 Horizon: A connected fleet of six open models

1960s theory that Stonehenge was a prehistoric computer

Which tools do Claude, Codex and Cursor choose? We measured 17k runs to find out

GPS glitched across the US by as much as 33 feet

Move in C++ without a std:move

Oscar Winner Brings Monsters to Life with His Simulation Software

US diesel prices hit a record high of $5.85 on average

Ask HN: Who is using MCP in production?

Xanadu was waiting for agents

Show HN: Reactor Atlas

Virtual Threads for a scripting language in Java 8 without Loom

Unusual Suspects

From Hookswitch to Grave