Bad error message for malformed GADTs
Compiling the following code:
data Foo a where
Bar :: a -> a
results in the following error message:
$ ghc-6.8.1 gadt.hs -XGADTs
gadt.hs:5:3:
Malformed constructor result type: a
In the result type of a data constructor: a
In the data type declaration for `Foo'
$
It would be nice if the error message mentioned the name of the offending data constructor (Bar
in this case) -- since there might be more than one.
Trac metadata
Trac field | Value |
---|---|
Version | 6.8.1 |
Type | Bug |
TypeOfFailure | OtherFailure |
Priority | normal |
Resolution | Unresolved |
Component | Compiler (Type checker) |
Test case | |
Differential revisions | |
BlockedBy | |
Related | |
Blocking | |
CC | |
Operating system | Unknown |
Architecture | Unknown |