Regex Explainer
Paste a regex, get back a sentence a human can read.
IntermediateCommand lineDev tool8–18hAI-buildable 4/5no setupworth shipping
What you're making
You find a horrible regular expression in some old code and have no idea what it does. Paste it in and this reads it back to you in plain English — 'matches an email-ish thing, then optionally a number, then end of line'. It also warns you when a pattern is written in a way that could hang your program on the wrong input.
Parses a regular expression into its component tokens and renders a readable explanation, with warnings for patterns at risk of catastrophic backtracking.
UI
Logic
Useful
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Core features · 7
- Accepts a pattern as an argument or from a pipe
- Breaks the pattern into tokens and explains each in words
- Explains groups, quantifiers and lookarounds in plain language
- Warns about nesting that can cause catastrophic backtracking
- Shows what a sample input would match
- Handles named groups and flags
- Reports a syntax error with the exact position
The interesting part
- Writing a real tokeniser for regex syntax, which is denser than it looks
- Explaining nested constructs without producing an unreadable wall of text
- Detecting backtracking risk without actually running the pattern
Once it works
- Add a reverse mode that builds a pattern from a description
- Add a test-string playground
- Support several regex dialects
Suggested stack
typescriptnodecommander