Detection of TF instance conflict depends on instance order
With 6.10 RC1, the following code compiles without complaint:
{-# OPTIONS -fglasgow-exts #-}
module OverlapTest where
type family A x
type instance A a = Bool
type instance A Int = Char
even though the overlapping instances "A a" and "A Int" conflict. Reordering the instances to
{-# OPTIONS -fglasgow-exts #-}
module OverlapTest where
type family A x
type instance A Int = Char
type instance A a = Bool
correctly doesn't compile, complaining about conflicting instances.
Trac metadata
Trac field | Value |
---|---|
Version | 6.9 |
Type | Bug |
TypeOfFailure | OtherFailure |
Priority | normal |
Resolution | Unresolved |
Component | Compiler (Type checker) |
Test case | |
Differential revisions | |
BlockedBy | |
Related | |
Blocking | |
CC | |
Operating system | Unknown/Multiple |
Architecture | Unknown/Multiple |