A terminal tool to parse and visualize regular expression.
Supported Syntax: Regular Expression Syntax
# build
make
# install
make installmake test# Parse a specified regular expression
build/regexparser '^\w+([-+.]\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*$'
# Read from stdin
echo "a+b*[0-9]+" | build/regexparser
# Print ansi-colored result
build/regexparser -c '[a-zA-Z0-9][-a-zA-Z0-9]{0,62}(\.[a-zA-Z0-9][-a-zA-Z0-9]{0,62})+\.?'
# Generate and parse a random regular expression
build/regexparser -g 20
# Output the syntax tree
build/regexparser -g 20 -f tree
# Run as HTTP server
build/regexparser -p 8080
# Show more usage details
build/regexparser -hRegular Expression: ^(\-|\+)?\d+(\.\d+)?$
╭Group #1╴╮
╷ ┌─┐ ╷ ╭╴╴╴╴╴Group #2╴╴╴╴╴╮
╷ ┌─┤-├─┐ ╷ ╷ ╷
╔══^══╗ ╷ │ └─┘ │ ╷ ╔═\d══╗ ╷ ┌─┐ ╔═\d══╗ ╷ ╔═$═╗
●──╣Start╠──┬─┼─┤ ┌─┐ ├─┼─┬──┬─╣Digit╠─┬──┬─┼─┤.├──┬─╣Digit╠─┬─┼─┬──╣End╠──◎
╚═════╝ │ ╷ └─┤+├─┘ ╷ │ │ ╚═════╝ │ │ ╷ └─┘ │ ╚═════╝ │ ╷ │ ╚═══╝
│ ╷ └─┘ ╷ │ └──↻1→∞───┘ │ ╷ └──↻1→∞───┘ ╷ │
│ ╷ ╷ │ │ ╰╴╴╴╴╴╴╴╴╴╴╴╴╴╴╴╴╴╴╯ │
│ ╰╴╴╴╴╴╴╴╴╴╯ │ └─────────↺0→1─────────┘
└────↺0→1─────┘
# DFA states table and graph output
build/regexparser -fd '(a[ab]c|b[bc]c|c[ac]c)'Regular Expression: (a[ab]c|b[bc]c|c[ac]c)
========== DFA Start ==========
Tokens: a b c
>State 0: 1 2 3
State 1: 4 4 -
State 2: - 4 4
State 3: 4 - 4
State 4: - - 8
*State 8: - - -
Accept States: 8
========== DFA End ==========
a
┌>─────┐
│ ↓
┏━━━━━┓c ╭────┴╮c ╭┴────╮c ╔═════╗
→┃ 0 ┃───>│ 3 │───>│ 4 │───>║ 8 ║
┗━━━━┬┛ ╰─────╯ ╰┬────╯ ╚═════╝
│ ↑
b│ │
┌──<┤ │
│ │a │
│ └>─────┐ │
│ │ b │
│ │ ┌>─────┤
│ │ │a │
│ │ ├>─────┤
│ c │ │ │
│ ┌>─────┼───┼──────┤
│ │b │ │ │
│ ├>─────┼───┼──────┘
↓ │ ↓ │
╭┴───┴╮ ╭┴───┴╮
│ 2 │ │ 1 │
╰─────╯ ╰─────╯
