On 02/05/07, [EMAIL PROTECTED] <[EMAIL PROTECTED]> wrote:
Hello,
could someone please explain why "fix" is necessary here:
fix (\f l -> if null l then [] else let (s,e) = break (==' ') l in s:f (drop 1
e))
Source: http://www.haskell.org/haskellwiki/Blow_your_mind
Because you're writing a recursive function. If you just had:
if null l then [] else let (s,e) = break (==' ') l in s:XXX (drop 1 e)
Then what goes in place of 'XXX'? There's no name for this particular
bit of code, so you can't call it. Using fix allows you to attach a
name to an arbitrary expression so that you can call it recursively.
The following would work exactly the same:
words :: String -> [String]
words l = if null l then [] else let (s,e) = break (==' ') l in
s:words (drop 1 e)
--
-David House, [EMAIL PROTECTED]
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