blob: 269ea8ff05f565a4d428c9d51dbfecede70fb664 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
|
rebindable6.hs:109:17: error:
Ambiguous type variable ‘t0’ arising from a do statement
prevents the constraint ‘(HasSeq
(IO a -> t0 -> IO b))’ from being solved.
(maybe you haven't applied a function to enough arguments?)
Relevant bindings include
g :: IO (Maybe b) (bound at rebindable6.hs:107:19)
f :: IO a (bound at rebindable6.hs:107:17)
test_do :: IO a -> IO (Maybe b) -> IO b
(bound at rebindable6.hs:107:9)
Probable fix: use a type annotation to specify what ‘t0’ should be.
These potential instance exist:
instance HasSeq (IO a -> IO b -> IO b)
-- Defined at rebindable6.hs:55:18
In a stmt of a 'do' block: f
In the expression:
do { f;
Just (b :: b) <- g;
return b }
In an equation for ‘test_do’:
test_do f g
= do { f;
Just (b :: b) <- g;
return b }
rebindable6.hs:110:17: error:
Ambiguous type variable ‘t1’ arising from a do statement
prevents the constraint ‘(HasFail
([Char] -> t1))’ from being solved.
(maybe you haven't applied a function to enough arguments?)
Probable fix: use a type annotation to specify what ‘t1’ should be.
These potential instance exist:
instance HasFail (String -> IO a)
-- Defined at rebindable6.hs:60:18
In a stmt of a 'do' block: Just (b :: b) <- g
In the expression:
do { f;
Just (b :: b) <- g;
return b }
In an equation for ‘test_do’:
test_do f g
= do { f;
Just (b :: b) <- g;
return b }
rebindable6.hs:111:17: error:
Ambiguous type variable ‘t1’ arising from a use of ‘return’
prevents the constraint ‘(HasReturn (b -> t1))’ from being solved.
(maybe you haven't applied a function to enough arguments?)
Relevant bindings include
b :: b (bound at rebindable6.hs:110:23)
g :: IO (Maybe b) (bound at rebindable6.hs:107:19)
test_do :: IO a -> IO (Maybe b) -> IO b
(bound at rebindable6.hs:107:9)
Probable fix: use a type annotation to specify what ‘t1’ should be.
These potential instance exist:
instance HasReturn (a -> IO a) -- Defined at rebindable6.hs:45:18
In a stmt of a 'do' block: return b
In the expression:
do { f;
Just (b :: b) <- g;
return b }
In an equation for ‘test_do’:
test_do f g
= do { f;
Just (b :: b) <- g;
return b }
|
