Welcome to NSRE’s documentation!

NSRE (Non-String Regular Expressions) is a new spin at regular expressions. It’s really abstract, even compared to regular expressions as you know them, but it’s also pretty powerful for some uses.

Here’s the twist: what if regular expressions could, instead of matching just character strings, match any sequence of anything?

from nsre import *

re = RegExp.from_ast(seq('hello, ') + (seq('foo') | seq('bar')))
assert re.match('hello, foo')

The main goal here is matching NLU grammars when there is several possible interpretations of a single word, however there is a lot of other things that you could do. You just need to understand what NSRE is and apply it to something.

Note

This is inspired by this article from Russ Cox, which explains how Thompson NFA work, except that I needed to add some features and then the implementation is much less elegant because I actually don’t know what I’m doing. But it seems to be working.

Indices and tables