Hal Daume III writes:
| Now, I want to say that if some data type 'd' is Traversable and
| another data type 'e' is Traversable, then the "combined data type"
| is Traversable. That is, for example, I want to say that a Tree of
| Lists is traversable, or that a List of Trees, or a List of Lis
Hi there,
I've just starting learning Haskell and, to
be quite frank, it gives me a cold sweat at
times.
What has me confused at present is why the
following code gives me :-
ActorTest.hs:8:
Ambiguous type variable(s) `a' in the
constraint `Action a'
arising from use of `validActions'
| >Furthermore, I can't even write:
| >
| >data (MyClass f a) => MyData2 f = MyData2 f
|
| Well now this is odd. I had no trouble simulating it with this:
|
| data MyData2 f = MyData2 f
|
| mkMyData2 :: (MyClass f a) => f -> MyData2 f
| mkMyData2 = MyData2
|
| Looks like extended Haskel
