blob: 09276728e2f8e1395cbad30f1fe36abc74565ac1 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
|
T3169.hs:13:22:
Could not deduce (elt ~ Map b elt)
from the context (Key a, Key b)
bound by the instance declaration at T3169.hs:10:10-36
‘elt’ is a rigid type variable bound by
the type signature for
lookup :: (a, b) -> Map (a, b) elt -> Maybe elt
at T3169.hs:12:3
Expected type: Map a (Map b elt)
Actual type: Map (a, b) elt
Relevant bindings include
m :: Map (a, b) elt (bound at T3169.hs:12:17)
b :: b (bound at T3169.hs:12:13)
lookup :: (a, b) -> Map (a, b) elt -> Maybe elt
(bound at T3169.hs:12:3)
In the second argument of ‘lookup’, namely ‘m’
In the expression: lookup a m :: Maybe (Map b elt)
|