Regexps can be fast, but they don't have to

LIghtning talk about regexp performance pitfalls in Ruby and browser. Wroclove.rb 2018

Transcript

1. REGEXPS CAN BE REGEXPS CAN BE FAST FAST BUT THEY DON'T HAVE TO BUT THEY DON'T HAVE TO MACIEK RZĄSA, TEXTMASTER MACIEK RZĄSA, TEXTMASTER @mjrzasa
4. BROWSER BROWSER <input id="operation" pattern='(\d+[+-]?)+='> https://regex-performance.github.io/input-en.html
5. RUBY RUBY 1231_1231_21312_1231231_12312 /(\d+_?)+\b/
6. 100% CPU ON PRODUCTION 100% CPU ON PRODUCTION Hello! → Witaj! → ¡Hola! → Salut ! Discourse client, described by Sam Saffron ::Typography.to_html_french # Insert a thin space before punctuation text.gsub(/(\s|)+([!?;]+(\s|\z))/, '&thinsp;\2\3') # <-58 spaces> GET /wp-login.php HTTP/1.1 69 GET /show.aspx HTTP/1.1 15
7. DEBUGGER DEBUGGER http://regex101.com
8. WHAT COULD I DO? WHAT COULD I DO?
10. JUST KIDDING JUST KIDDING
11. WHAT COULD I DO? WHAT COULD I DO? be specific test almost matching input don't believe in magic, there is just software I will send links on twitter