On Sun, Apr 18, 2010 at 10:25 AM, Sean Leather leat...@cs.uu.nl wrote:
This is the annoying part about Haskell . I can not understand composition
.
One of the ways of understanding composition (and many other functions in
Haskell) is by trying to understand its type. Here it is shown by
Using composition can be tricky with more than one arg. I just want to
be sure you're not really looking for something like:
func :: (a - Bool) - (b - Bool) - (a - b - Bool)
keeping with your given type I think you're looking for something like:
func f1 f2 x = (f1 x) || (f2 x)
I'm sure there
This is the annoying part about Haskell . I can not understand composition
.
One of the ways of understanding composition (and many other functions in
Haskell) is by trying to understand its type. Here it is shown by looking at
the type in the interpreter GHCi.
*Main :t (.)
(.) :: (b - c) -
To do this, you need not just fmap (composition), but also ap, or the combined
form, liftA2:
func = liftA2 (||)
Bob
On 18 Apr 2010, at 18:21, Keith Sheppard wrote:
Using composition can be tricky with more than one arg. I just want to
be sure you're not really looking for something like:
Thanks a lot guys you were really helpful
func f1 f2 x = (f1 x) || (f2 x) is working for me
On Sun, Apr 18, 2010 at 6:27 PM, Thomas Davie tom.da...@gmail.com wrote:
To do this, you need not just fmap (composition), but also ap, or the
combined form, liftA2:
func = liftA2 (||)
Bob
On
