Re: [Haskell-cafe] Missing join and split

Josef Svenningsson writes:

On Dec 28, 2007 11:40 PM, Mitar wrote:

...

Would not it be interesting and useful (but not really efficient) to have patterns something like:

foo :: Eq a => a -> ... foo (_{4}'b') = ...

which would match a list with four elements ending with an element 'b'. Or:

foo (_+';'_+';'_) = ...

which would match a list with embedded two ';' elements. (Last _ matched the remaining of the list.)

I suggest you take at look at HaRP, Haskell Regular Patterns: http://www.cs.chalmers.se/~d00nibro/harp/

It hasn't been updated for a while but it should still be useable.

Also of interest might be XHaskell http://taichi.ddns.comp.nus.edu.sg/taichiwiki/XhaskellHomePage which adds XDuce style regular expression pattern matching to Haskell. Martin