Associated Type Synonyms do not unfold in InstanceSigs
{-# LANGUAGE InstanceSigs, TypeFamilies #-}
class C a where
type T a
m :: T a
instance C Int where
type T Int = String
m :: String
m = "bla"
-- Method signature does not match class; it should be m :: T Int
-- In the instance declaration for ‘C Int’
As T Int
is a synonym of String
, m :: String
should be a valid type signature alternative to m :: T Int
Trac metadata
Trac field | Value |
---|---|
Version | 7.8.3 |
Type | Bug |
TypeOfFailure | OtherFailure |
Priority | normal |
Resolution | Unresolved |
Component | Compiler (Type checker) |
Test case | |
Differential revisions | |
BlockedBy | |
Related | |
Blocking | |
CC | |
Operating system | |
Architecture |