Or even shorter:
subst e l = concatMap $ \x->if x==e then l else [x]
I kinda like the list comprehension version too
subst e l1 l2 = [ r | x <- l2, r <- if x==e then l1 else [x] ]
On Sep 18, 2006, at 10:54 , Jón Fairbairn wrote:
Andrea Rossato <[EMAIL PROTECTED]> writes:
On Mon, Sep 18, 2006 at 12:42:59PM +0100, Jón Fairbairn wrote:
And if you do that, you can write it like this:
subst e l'
= concat . map subst_elem
where subst_elem x
| x == e = l'
| otherwise = [x]
Pretty. Just to many keystrokes.
Keystrokes? Learn to touchtype!
This should take two keystrokes less, probably:
subst e l [] = []
subst e l (x:xs) = if x == e then l ++ xs else x : subst e l xs
but if you want short, do this:
subst e l' = concat.map (\x->if x==e then l' else [x])
which beats yours by twenty seven characters and one bug ;-P
--
Jón Fairbairn
[EMAIL PROTECTED]
http://www.chaos.org.uk/~jf/Stuff-I-dont-want.html (updated
2006-09-13)
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