Rex: Regular Expression Exploration for .NET

Today i saw a new project from Microsoft research called Rex.

Rex is a simple command line tool that takes a .NET regex pattern or several regex patterns and generates matching string(s) for them. Rex can also be used through an API. Rex is fast, using a novel approach to solve this problem. When several regexes are provided, rex can be used to generate members that match all the regex

I asked my self several time on the valid string for a given regex

Download Here / Project Site