[Haskell-beginners] Re: Defining 'words' in terms of 'span'

[Roger Whittaker]

Thanks for the suggestions - I think the idea was that you had to
use a recursive definition in terms of span.

I eventually did this, but didn't feel it was at all nice or
elegant:

import Data.Char

mywords :: [Char] -> [[Char]]

mywords l |  ((snd (span isAlpha l)) == "" && (fst (span isAlpha l)) == "") = []
          |  ((snd (span isAlpha l)) == "" && (fst (span isAlpha l)) /= "") = [fst (span isAlpha l)]
          |  (fst (span isAlpha l))  == "" =  mywords (tail (snd (span isAlpha l)))
          |  otherwise = [fst (span isAlpha l)] ++ mywords (tail (snd (span isAlpha l)))


-- 
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Roger Whittaker
roger at disruptive.org.uk
http://disruptive.org.uk
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