[Haskell-beginners] Type error in function binding

Markus Läll markus.l2ll at gmail.com
Mon Apr 2 17:00:39 CEST 2012


You're missing some parenthesis. Instead of "mycounter tail st" write
"mycounter (tail st)".

On Mon, Apr 2, 2012 at 5:50 PM, bahadýr altan <doaltan at yahoo.co.uk> wrote:
> Hi.
> I'm trying to write a code which counts the number of  'a's  in a string.
> it looks like this :
>
> mycounter st =
> if st == [] then 0
> else if head st == 'a' then 1 + mycounter tail st else mycounter tail st
>
> but it gives this error :
> ERROR "deneme.hs":19 - Type error in function binding
> *** Term           :mycounter
> *** Type           : [Char] -> b
> *** Does not match : ([a] -> [a]) -> [Char] -> b
> *** Because        : unification would give infinite type
>
> I have no idea about what I'm doing wrong. Can you help me with this please?
>
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>



-- 
Markus Läll



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