grex

name	grex
description	Use this skill when the user wants to generate regular expressions from test cases, convert patterns to character classes, or automate regex creation from examples.

grex Plugin

Generate regular expressions from user-provided test cases. Supports digit, whitespace, word character conversions, repetition detection, case-insensitive matching, and capturing groups.

Commands

Regex Generation

• grex regex generate — Generate regex from test cases

Utility

• grex _ _ — Passthrough to grex CLI

Usage Examples

• "Generate a regex from these strings"
• "Create a pattern matching these examples"
• "Convert these test cases to a regex"
• "Generate regex with character classes"

Installation

brew install grex

Or via Cargo:

cargo install grex

Examples

# Basic regex generation from test cases
grex regex generate a b c

# Read test cases from file
grex regex generate --file test_cases.txt

# Use Unix pipeline
cat test_cases.txt | grex regex generate -

# Convert digits to \\d
grex regex generate --digits 123 456 789

# Convert non-digits to \\D
grex regex generate --non-digits abc def ghi

# Convert whitespace to \\s
grex regex generate --spaces "hello world" "foo bar"

# Convert non-whitespace to \\S
grex regex generate --non-spaces helloworld foobar

# Convert word characters to \\w
grex regex generate --words hello_world foo_bar

# Convert non-word characters to \\W
grex regex generate --non-words hello@world foo#bar

# Escape non-ASCII characters
grex regex generate --escape "café" "naïve"

# Detect repeated substrings
grex regex generate --repetitions abcabc xyzxyz

# Specify minimum repetitions
grex regex generate --repetitions --min-repetitions 2 abcabc xyzxyz

# Specify minimum substring length
grex regex generate --repetitions --min-substring-length 2 abcabc xyzxyz

# Remove anchors
grex regex generate --no-anchors abc xyz

# Verbose mode for nicer regex
grex regex generate --verbose abc xyz

# Colorize output
grex regex generate --colorize abc xyz

# Case-insensitive matching
grex regex generate --ignore-case abc ABC xyz

# Use capturing groups
grex regex generate --capture-groups abc xyz

# Multiple options combined
grex regex generate --digits --words --verbose 123abc 456def

# Any grex command with passthrough
grex _ _ --digits --spaces abc 123

Key Features

• Test case input — Pass test cases directly or from file
• Pipeline support — Receive input from Unix pipes
• Character classes — Convert digits, whitespace, word characters
• Repetition detection — Detect repeated substrings automatically
• Anchor control — Add or remove start/end anchors
• Case options — Case-insensitive matching support
• Group options — Non-capturing or capturing groups
• Unicode support — Escape non-ASCII characters
• Syntax highlighting — Colorize output for readability
• Verbose mode — Generate nicer-looking regex

Notes

• Default includes both ^ and $ anchors
• Can read from stdin with - argument
• Supports Python library bindings
• Detects repetitions by default with min 1 repetition
• Useful for learning regex or automating pattern creation