Regenerate

Regenerate is a tool to generate test-cases for regular expression engines.

Regenerate takes a regular expression and generates strings that match it. It handles most posix extended regular expressions along with complement (~a) and intersection (a&b). Since it handles complement, it can also generate strings that don't match a given regular expression.

Regenerate is both a tool to generate samples and a library to define test harnesses. There is also an online demo of the tool.

Command line tool

The command line tool can generate example strings matching a given regex. it takes a regex using the POSIX extended regular expression syntax (or ERE for short). For example, here is a set of samples that are matched by the regex (1(01*0)*1|0)* on the alphabet composed of 0 and 1:

% regenerate gen --sample 5 --alphabet "01" "(1(01*0)*1|0)*"
01001
11000
000011
001001
001100
011000
111111
0000110
0011000
0101101
1011101
1101001
00010101
00100100

Please consult the help for more details, or play with the online demo.

Library

The regenerate library allow to easily define test harnesses for regular expression engines. It contains utilities to randomly generate regular expressions and associated positive and negative samples. The main entry point of the library is the Regenerate.arbitrary function which exposes the sample generation as a qcheck generator.

See test_re.ml for an example test harness for re. You can also find (wip) documentation for the dev version of the API.

Website

Code for the online demo is hosted in the web/ directory. It uses fairly simple js_of_ocaml code.