id,summary,reporter,owner,description,type,status,priority,milestone,component,version,resolution,keywords,cc,os,architecture,failure,difficulty,testcase,blockedby,blocking,related
2182,"ghc sessions (--make, --interactive, ghc api) erroneously retain instances",claus,,"{{{
$ compiler/stage2/ghc-inplace --interactive
GHCi, version 6.9.20080317: http://www.haskell.org/ghc/  :? for help
Loading package base ... linking ... done.
Prelude> :i Functor
class Functor f where fmap :: (a -> b) -> f a -> f b
        -- Defined in GHC.Base
instance Functor Maybe -- Defined in Data.Maybe
instance Functor [] -- Defined in GHC.Base
instance Functor IO -- Defined in GHC.IOBase
Prelude> fmap not (True,True)

<interactive>:1:0:
    No instance for (Functor ((,) Bool))
      arising from a use of `fmap' at <interactive>:1:0-19
    Possible fix: add an instance declaration for (Functor ((,) Bool))
    In the expression: fmap not (True, True)
    In the definition of `it': it = fmap not (True, True)
Prelude> :m +Data.Array
Prelude Data.Array> :i Functor
class Functor f where fmap :: (a -> b) -> f a -> f b
        -- Defined in GHC.Base
instance (Ix i) => Functor (Array i) -- Defined in GHC.Arr
instance Functor ((->) r) -- Defined in Control.Monad.Instances
instance Functor ((,) a) -- Defined in Control.Monad.Instances
instance Functor (Either a) -- Defined in Control.Monad.Instances
instance Functor Maybe -- Defined in Data.Maybe
instance Functor [] -- Defined in GHC.Base
instance Functor IO -- Defined in GHC.IOBase
Prelude Data.Array> fmap not (True,True)
(True,False)
Prelude Data.Array> :m -Data.Array
Prelude> :i Functor
class Functor f where fmap :: (a -> b) -> f a -> f b
        -- Defined in GHC.Base
instance Functor ((->) r) -- Defined in Control.Monad.Instances
instance Functor ((,) a) -- Defined in Control.Monad.Instances
instance Functor (Either a) -- Defined in Control.Monad.Instances
instance Functor Maybe -- Defined in Data.Maybe
instance Functor [] -- Defined in GHC.Base
instance Functor IO -- Defined in GHC.IOBase
Prelude> fmap not (True,True)
(True,False)
}}}",bug,new,low,_|_,GHCi,6.9,,,,Unknown/Multiple,Unknown/Multiple,,Unknown,,,,