I think you're looking for Data.List.isInfixOf.
Alex
On Thu, Apr 24, 2008 at 7:40 PM, Dan Weston
cetin tozkoparan wrote:
I wrote this code and Can it be less? [2,4,5] list is sub list of [3,7,*2,4,5*,9] list and return True but not of [3,7,*4,2,5*,9] list ; return False
sublist :: Eq a => [a] -> [a] -> Bool sublist [] _ = True sublist (_:_) [] = False sublist (x:xs) (y:ys) | x == y = if isEqual (x:xs) (y:ys) == False then sublist (x:xs) ys else True | otherwise = sublist (x:xs) ys
isEqual :: Eq a => [a] -> [a] -> Bool isEqual [] _ = True isEqual (_:_) [] = False isEqual (x:xs) (y:ys) | x==y = isEqual xs ys | otherwise = False
One way is to use existing library functions as Henning suggested (but maybe you missed it because he mischievously changed the subject!)
Henning Thielemann wrote:
try 'List.tails' and 'List.isPrefixOf'
You should be able to define sublist using only some combination of the following (and one pair of parentheses) in one line of code!
import List(isPrefixOf,tails)
(.) :: (b -> c) -> (a -> b) -> a -> c any :: (a -> Bool) -> [a] -> Bool tails :: [a] -> [[a]] isPrefixOf :: (Eq a) => [a] -> [a] -> Bool _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe