Regex-Engine

A simple, but powerful regular expression recognizer, made using the Ken Thompson algorithm, presented in his paper Regular Expression Search Algorithm (1968).

It supports:

• Concatenation,
• Union (|),
• Closure (*),
• One or More (+),
• Zero or One (?) ,
• Grouping (( )) and
• Range ([start-end]) regex operators.

Example

import regeng

#grouping, union, closure and concatenation
r = regeng.Regex('(a|b)*c')

r.match('baabac') #True
r.match('cabbba') #False
r.match('c') #True

#match an acepptable identifier name
r = regeng.Regex('([a-z]|[A-Z]|_)([a-z]|[A-Z]|[0-9])*')

r.match('') #False
r.match('identifer') #True
r.match('987c') #False
r.match('_usr501132') #True

#match numbers from 0 to 99
r = regeng.Regex('[0-9]?[0-9]')

r.match('00') #True
r.match('125') #False
r.match('12') #True
r.match('5') #True

Running Tests

$ git clone https://github.com/tonisidneimc/Regex-Engine
$ cd Regex-Engine
$ make run