grex

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