A few simple questions: What standard library function can be used to replace substring in a string (or sub-list in a list) ? I wrote my own version, please criticize: -- replace all occurances of "123" with "58" in a string: test = replStr "abc123def123gh123ikl" "123" "58" {-- In a string replace all occurances of an 'old' substring with a 'new' substring --} replStr str old new = foldr ((\newSub before after -> before ++ newSub ++ after) new) [] chunks where chunks = splitStr str old {-- Split string into a list of chunks. Chunks are substrings located in a string between 'sub' substrings --} splitStr str sub = mkChunkLst str sub [] where -- mkChunkLst 'src string' 'substr-to-extract' 'list of chunks' -- makes list of chunks located between 'substr-to-extract' pieces in src string mkChunkLst [] _ chunkLst = chunkLst mkChunkLst str sub chunkLst = mkChunkLst after sub (chunkLst ++ [chunk]) where (chunk, _, after) = takeOut str sub [] [] {-- Take out substring from a string. String is divided into: "before substr" ++ "match" ++ "after substr" where 'match' is substring to split out --} takeOut after [] before match = (before, match, after) takeOut [] _ before match = (before, match, []) takeOut (x:xs) (y:ys) before match | x == y = takeOut xs ys before (match ++ [x]) | otherwise = takeOut xs (y:ys) (before ++ match ++ [x]) [] -- Dmitri O. Kondratiev dokondr@gmail.com http://www.geocities.com/dkondr