[Haskell-cafe] Re: Reversing a string of words: C# v Perl V Ruby v Haskell

[Donald Bruce Stewart]

ulfn:
> 
> On Dec 13, 2006, at 3:54 AM, Yitz Gale wrote:
> 
> >Nice. Here is something similar:
> >
> >reverseWords = concat . reverse . groupBy eqsp
> >  where eqsp x y = isSpace x == isSpace y
> 
> This can be made even nicer using the 'on' function [1]:
> 
> reverseWords = concat . reverse . groupBy ((==) `on` isSpace)
> 
> [1] http://www.haskell.org/pipermail/libraries/2006-November/006156.html

Lambdabot trick(tm), use 'join' in the [] monad, instead of 'concat'

    join . reverse . groupBy ((==) `on` isSpace)

-- Don