Improved the performance of the regular languages compiler: generate …

[jonathanslenders]

…fewer and better regexes.

[laixintao]

Hi @jonathanslenders thanks for the work. The compiling time saved a lot.

I read the code and think it's good, but there is a problem with completion on space.

eg:
On this branch, when I type SPACE the completion didn't show up:

But on prompt_toolkit(2.0 which is iredis current use) it works fine:

[jonathanslenders]

@laixintao : Thank you for the feedback! I really appreciate you trying it out.
This bug needs to be fixed before merging it. I'll look into that.

[jonathanslenders]

@laixintao: can you check again against this branch?
I did a few bug fixes, and maybe the performance is a bit better even.

I think I got it right, and the above bug is solved.
Still need to clean up the code, before merging.

[laixintao]

@jonathanslenders Thanks!

I tested with this branch, the cost time down to `.7 seconds, and all the compilations work fine as far as I tested.

From my log, the _re_prefix_patterns that need to compile down to 496 only (previous ~8000), that's amazing! Excellent work!

 INFO Compiled _re_prefix_pattern: 496 DEBUG [compile] Compile finished! Cost: 1.7887732982635498