functions on records with overloaded names can be given a too-specific type
Here's a reduced test-case showing a discrepancy between the symmetric functions foo
and bar
; the inferred type for foo
is too specific.
data T a = A{ m1 :: a } | B{ m1, m2 :: a } | C{ m2 :: a }
-- bar :: (t -> a) -> T t -> T a
bar f x@(A m) = x{m1 = f m}
-- foo :: (a -> a) -> T a -> T a
foo f x@(C m) = x{m2 = f m}
Trac metadata
Trac field | Value |
---|---|
Version | 6.10.1 |
Type | Bug |
TypeOfFailure | OtherFailure |
Priority | normal |
Resolution | Unresolved |
Component | Compiler (Type checker) |
Test case | |
Differential revisions | |
BlockedBy | |
Related | |
Blocking | |
CC | |
Operating system | |
Architecture |