Strange behavior of GHC by writing the types in GHCi
- A: you type
:set +t
then you write1:2
, the answer is:\\
Prelude> :set +t
Prelude> 1:2
<interactive>:8:1: error:
* Non type-variable argument in the constraint: Num [a]
(Use FlexibleContexts to permit this)
* When checking the inferred type
it :: forall a. (Num [a], Num a) => [a]
\\
- B: you type
:t 1:2
, the answer is:\\
Prelude> :t 1:2
1:2 :: (Num [a], Num a) => [a]
\\ There is an obvious bug. Don't answer me that this behavior is correct, please! The two answers should be the same. Either answer A or answer B.
Trac metadata
Trac field | Value |
---|---|
Version | 8.0.2 |
Type | Bug |
TypeOfFailure | OtherFailure |
Priority | normal |
Resolution | Unresolved |
Component | GHCi |
Test case | |
Differential revisions | |
BlockedBy | |
Related | |
Blocking | |
CC | |
Operating system | |
Architecture |