Slow generation of some RegExps

[TheJavaGuy]

Hello @mifmif ,

I noticed one issue when generating some RegExps. If we try this:

Generex generex = new Generex("(.{1,6})( *, *(.{1,6})){0,5}");
System.out.println(generex.random());

it takes about 1 second to finish. But, if we try this RegEx:

Generex generex = new Generex("(.{1,6})( *, *(.{1,6})){0,12}");
System.out.println(generex.random());

it takes about 40 seconds.

Finally, the code

Generex generex = new Generex("(.{1,6})( *, *(.{1,6})){0,15}");
System.out.println(generex.random());

took a whopping 3 minutes and generated one character as a result.

Now I'm perfectly aware that users can write all sorts of RegExps. It's probably impossible to make code which efficiently generates them all. Yet I hope there's a possibility that for some cases generation might be faster.