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  • #5962

Closed
Open
Opened Mar 23, 2012 by NickSmallbone@trac-NickSmallbone

Data.Typeable: types which should compare equal don't

Here are two ways to construct a TypeRep for the type () -> ():

Prelude> import Data.Typeable
Prelude Data.Typeable> let unitToUnit = typeOf (\() -> ())
Prelude Data.Typeable> let unitToUnit' = mkFunTy (typeOf ()) (typeOf ())

It seems to work:

Prelude Data.Typeable> unitToUnit
() -> ()
Prelude Data.Typeable> unitToUnit'
() -> ()

But the two TypeReps are not equal:

Prelude Data.Typeable> unitToUnit == unitToUnit'
False
Trac metadata
Trac field Value
Version 7.4.1
Type Bug
TypeOfFailure OtherFailure
Priority normal
Resolution Unresolved
Component libraries/base
Test case
Differential revisions
BlockedBy
Related
Blocking
CC
Operating system
Architecture
Assignee
Assign to
7.4.3
Milestone
7.4.3
Assign milestone
Time tracking
None
Due date
None
Reference: ghc/ghc#5962