slide: useful function?

[Jorge Adriano]

Doesn't seem that usefull to me, you can get the several consecutive ones=
 by=20
applying tails to your list.


> I want to propose the following function slide, which is like map, but
> depends not on one value of
> a list, but on several consecutive ones.
>
> slide :: ([a] -> b) -> [a] -> [b]
> slide f [] =3D []
> slide f xs =3D f xs : slide f (tail xs)

slide f =3D map f.init.tails
The init is needed because you don't apply f to the empty List.
If you did, then it would be just.

> slide :: ([a] -> b) -> [a] -> [b]
> slide f [] =3D f [] <---------------
> slide f xs =3D f xs : slide f (tail xs)

slide f =3D map f.tails


J.A.