Re: [Haskell-cafe] Newbie: Replacing substring?

2008/7/22 Ronald Guida :

2008/7/22 Dmitri O.Kondratiev :

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On the side: The more I use Haskell - the more I like it ! It helps me think about the problem I solve much more clearly then when I use imperative language.

If I want to replace a substring in a string, then I would search my string left to right, looking for any occurrence of the substring. If I find such an occurrence, I would replace it and continue searching from immediately after the replacement. This algorithm can be directly expressed in Haskell. More efficient algorithms do exist.

Your idea but expressed in a more elegant fashion (maybe...) : replace :: (Eq a) => [a] -> [a] -> [a] -> [a] replace _ _ [] = [] replace old new xs@(y:ys) = case stripPrefix old xs of Nothing -> y : replace old new ys Just ys' -> new ++ replace old new ys' -- Jedaï