Hi,
You want a function that converts a string into a list of strings,
i.e. with the type signature:
String -> [String]
Go to hoogle (http://haskell.org/hoogle) and search for that:
http://haskell.org/hoogle/?q=String->[String]
(if you can't be bothered to do that, the answer is "lines" ;)
Thanks
Neil
On 9/30/06, Andrea Rossato
Hello!
I've been trying for quite some time to find an elegant solution to cut long strings into lines, but the only solution I was able to come up is the following piece of ugly code.
Is there a library function for that? What kind of approach would you suggest?
Thanks for your kind attention.
Andrea
Here's the code:
-- does the actual job wrapString str = foldr addNL "" $ rmFirstSpace $ concat $ splitS (getIndx $ indx str) str
-- gets the indexes of the spaces within a string indx = findIndices (\x -> if x == ' ' then True else False)
-- gets the indexes of where to split the string into lines: lines -- must be between 60 and 75 char long getIndx :: [Int] -> [Int] getIndx = takeFirst . checkBound . (delete 0) . nub . map (\x -> if x > 60 && x `rem` 60 >= 0 && x `rem` 70 <= 10 then x else 0)
-- groups indexes when their distance is too short checkBound = groupBy (\x y -> if y - x < 10 then True else False)
-- takes the first index of a group of indexes takeFirst = map (\(x:xs) -> x)
-- split a string given a list of indexes splitS _ [] = [] splitS (x:xs) (ls) = [take x ls] : splitS (map (\i -> i - x) xs) (drop x ls) splitS _ ls = [ls]:[]
-- remove the first space from the begging of a string in a list of strings rmFirstSpace = map (\(x:xs) -> if x == ' ' then xs else x:xs)
-- used by foldr to fold the list of substrings addNL s s1 = s ++ "\n" ++ s1
try with putStrLn $ wrapString longString where: longString = "The Haskell XML Toolbox (HXT) is a collection of tools for processing XML with Haskell. The core component of the Haskell XML Toolbox is a domain specific language, consisting of a set of combinators, for processing XML trees in a simple and elegant way. The combinator library is based on the concept of arrows. The main component is a validating and namespace aware XML-Parser that supports almost fully the XML 1.0 Standard. Extensions are a validator for RelaxNG and an XPath evaluator." _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe