Partial type signatures generate typed hole warnings
GHCi generates typed hole warnings in type signatures even when PartialTypeSignatures is enabled:
> :set -XPartialTypeSignatures
> :t (==) :: Char -> _
<interactive>:1:17: Warning:
Found hole ‘_’ with type: Char -> Bool
In an expression type signature: Char -> _
In the expression: (==) :: Char -> _
(==) :: Char -> _ :: Char -> Char -> Bool
> :set -XNoPartialTypeSignatures
> :t (==) :: Char -> _
<interactive>:1:17:
Found hole ‘_’ with type: Char -> Bool
To use the inferred type, enable PartialTypeSignatures
In an expression type signature: Char -> _
In the expression: (==) :: Char -> _Similarly, GHC 7.10.1, when given the following source,
{-# LANGUAGE PartialTypeSignatures #-}
f = (==) :: Char -> _
main = return ()mentions that it "found a hole".
Trac metadata
| Trac field | Value |
|---|---|
| Version | 7.10.1 |
| Type | Bug |
| TypeOfFailure | OtherFailure |
| Priority | normal |
| Resolution | Unresolved |
| Component | Compiler |
| Test case | |
| Differential revisions | |
| BlockedBy | |
| Related | |
| Blocking | |
| CC | |
| Operating system | |
| Architecture |