blob: 395149121eedf95edf90ca4533412a1c4aa8481c (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
|
Simple14.hs:8:8: error:
Couldn't match type ‘z0’ with ‘z’
‘z0’ is untouchable
inside the constraints: x ~ y
bound by the type signature for:
eqE :: (x ~ y) => EQ_ z0 z0
at Simple14.hs:8:8-39
‘z’ is a rigid type variable bound by
the type signature for:
eqE :: forall x y z p. EQ_ x y -> ((x ~ y) => EQ_ z z) -> p
at Simple14.hs:8:8
Expected type: EQ_ z0 z0
Actual type: EQ_ z z
In the ambiguity check for ‘eqE’
To defer the ambiguity check to use sites, enable AllowAmbiguousTypes
In the type signature:
eqE :: EQ_ x y -> (x ~ y => EQ_ z z) -> p
|
