Library to generate text from regular expression

Question

For example, given a pattern for matching email, I should get an array of strings that can be matched by the same regex pattern. Another example:

Input:

(a|b)[cd]{2}\1

Output:

acca 
adca 
acda 
adda 
bccb 
bdcb 
bcdb 
bddb 

I would like to use this library to generate dummy data for given pattern that can be used for testing my web app.

I found this website that has implemented it: https://regldg.com/tryit.php, but it is a binary executable. I'm looking for a library for PHP, JS, etc.

Answer 1

The python library rstr has the function xeger() to do what you need by using random strings and only returning ones that match:

Example

Install with pip install rstr

In [1]: from __future__ import print_function

In [2]: import rstr

In [3]: for dummy in range(10):
   ...:     print(rstr.xeger(r"(a|b)[cd]{2}\1"))
   ...:
acca
bddb
adda
bdcb
bccb
bcdb
adca
bccb
bccb
acda

Warning

For complex re patterns this might take a long time to generate any matches.

Answer 2

Does greenery do what you want? For instance,

>>> from greenery.lego import parse
>>> rep = parse('(a|b)[cd]{2}\1')
>>> list(rep.strings())
['acc\x01', 'acd\x01', 'adc\x01', 'add\x01', 'bcc\x01', 'bcd\x01', 'bdc\x01', 'bdd\x01']