
Regular expression engine in 14 lines of Python - 13ren
http://paste.lisp.org/display/24849
======
silentbicycle
Not exactly an engine. You have to do the parsing yourself. A simple parser
would do, but it's not _trivial_ , and would very likely at least double the
size. It's also probably far from efficient. Some of the core functionality is
there, though.

I started to write a quick parser for it to post here, but I have to get
going... Letters, numbers, etc. can just be passed as char(c) literals, star
and plus modify the most recent thing appended to the list, (a|b|c) groupings
recursively call the parser and wrap the result. The whole thing gets wrapped
in nested-pair seq calls, e.g. seq(a, seq(b, seq(c))) like in box-and-pair
notation.

