[Haskell-cafe] Quicksort in Haskell

[Peter Scott]

You can narrow down the problem by commenting out the part of the file
that's giving you problems, and trying out the other functions in ghci. In
your case, the main function is causing a parsing error. If you comment it
out, you can verify that quicksort works correctly. Then look at your main
function and see where it's broken. Try this out, and compare with what you
wrote:

module Main (main) where

quicksort [] = []
quicksort (s:xs) = quicksort [x | x <- xs, x < s] ++ [s] ++ quicksort [x |
x <- xs, x >= s]
main = do
  putStr "Ingrese la lista\n"
  line <- getLine
  let xs = read line :: [Int]
  print (quicksort xs)

-Peter

On Mon, Nov 7, 2011 at 3:41 PM, yrazes <yrazes at gmail.com> wrote:

> Sorry, but I got this error while I compile it.
> *
> *
> *[yulys at yulys haskell]$ ghc -o quick quick.hs*
> *[1 of 1] Compiling Main             ( quick.hs, quick.o )*
> *
> *
> *quick.hs:7:11: parse error on input `<-'*
> *[yulys at yulys haskell]$ *
>
>
>
>
>
> On Mon, Nov 7, 2011 at 4:23 PM, KC <kc1956 at gmail.com> wrote:
>
>> What is your question?
>>
>>
>>
>> On Mon, Nov 7, 2011 at 9:45 AM, yrazes <yrazes at gmail.com> wrote:
>> > module Main (main) where
>> > quicksort [] = []
>> > quicksort (s:xs) = quicksort [x|x <- xs,x < s] ++ [s] ++ quicksort [x|x
>> <-
>> > xs,x >= s]
>> > main = putStr "Ingrese la lista\n"
>> >        [xs] <- getLine
>> > _______________________________________________
>> > Haskell-Cafe mailing list
>> > Haskell-Cafe at haskell.org
>> > http://www.haskell.org/mailman/listinfo/haskell-cafe
>> >
>> >
>>
>>
>>
>> --
>> --
>> Regards,
>> KC
>>
>
>
> _______________________________________________
> Haskell-Cafe mailing list
> Haskell-Cafe at haskell.org
> http://www.haskell.org/mailman/listinfo/haskell-cafe
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.haskell.org/pipermail/haskell-cafe/attachments/20111107/9e9b0f60/attachment.htm>