[Haskell-beginners] Are these soloutions all valid and a good use of Haskell
Leza Morais Lutonda
leza.ml at fecrd.cujae.edu.cu
Mon Nov 10 18:52:21 UTC 2014
On 10/11/14 10:10, Roelof Wobben wrote:
> No problem .
> Im strugelling to make acc work.
> I try to say that if the input list has only 1 item the outcome is the
> head of that list.
> But doing
> acc = Just (head a) or doing acc = Just (head acc) gives both that
> acc or a is not in scope
The `a` in the type signature `acc :: a -> Maybe a -> Maybe a` is not a
variable name, it is a type.
> also doing acc x = Just (head x) gives a error messages that the types
> are not matching.
:t Just (head x)
:t acc x
Maybe a -> Maybe a
So, the compiler is right!
Leza Morais Lutonda, Lemol-C
Electronic and Telecommunication Engineer
Software Development and Architecture Enthusiast
50 Aniversario de la Cujae. Inaugurada por Fidel el 2 de diciembre de 1964 http://cujae.edu.cu
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