On Sun, Oct 17, 2004 at 11:41:59AM -0700, Peter Stranney wrote: > Thanks guys for all your help, finally through code, sweat and tears i have found > the solution; > > isSubStrand:: String -> String -> Bool > isSubStrand [] [] = True > isSubStrand [] (y:ys) = False > isSubStrand (x:xs) [] = False > isSubStrand (x:xs) (y:ys) > | length(x:xs)>length(y:ys) = False > | take (length (x:xs)) (y:ys)==(x:xs) = True > | otherwise = isSubStrand (x:xs) ys > > thanks again > Peter Stranney
Now that you found it, we might as well tell you the other solution: import List -- Point-free (beware of the monomorphism-restriction) isSubStrand' :: Eq a => [a] -> [a] -> Bool isSubStrand' = flip (.) tails . any . isPrefixOf -- and point-full isSubStrand'' x y = any (x`isPrefixOf`) (tails y) Groetjes, Remi "feeling mean" Turk -- Nobody can be exactly like me. Even I have trouble doing it. _______________________________________________ Haskell-Cafe mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/haskell-cafe
