Definition
Plain language
A compact code for describing text patterns, used to find or pull out matching pieces of text.
As stated in the literature
Regular expression — a formal pattern language for matching and extracting substrings; used in this corpus for answer extraction in math pipelines and whole-word span matching in guards.
Also called: regular expression, regexes, regular expressions
Why it matters: It is a compact, powerful way to find and pull out exactly the text patterns you want from messy data.
For example, you can write a regex that matches any string shaped like an email address so a form can flag invalid entries.
Heard on the show
“… There's a find-and-replace task where the dead-end warning is: do not check the "regular expressions" box — because if you do, the question mark in the text gets treated as a special pattern …”Episode 155 — Why a Flawless Demo Makes a Worse Computer-Using Agent, And the Fix