Rewrite rules for parser primitives

[lrworth]

I've just replaced

M.many (M.anySingleBut '\n')

with

M.takeWhileP Nothing (/= '\n')

and my program used an order of magnitude less memory and time. It seems the latter should always be preferred.

Would it be good for a REWRITE rule to make this substitution (and other similar ones)? I'd be happy to submit a PR.

[lrworth]

The substitution I made is not always possible because of the types. The rule could apply chunkToTokens to retain the list result, but that may undo the performance gain.

I'll leave this open in case someone has a bright idea.