| > * Clarify the spec to say that a newtype can only be automatically | > unwrapped if the newtype constructor (MkN in this case) is in | > scope | | I agree up to here. For user-defined types, not exporting the | constructor should be a guarantee of abstraction. | | > It happens that a large set of types from Foreign.C.Types, such as | > CInt and friends, are exported without their constructors, so adopting | > this new rule would require us to change Foreign.C.Types to expose the | > representation of CInt and friends. (As it happens, nhc requires this | > already, so there's some #ifdeffery there already.) | | The thing about CInt though is that it is supposed to be abstract *and* | an FFI type. I want to think of it as a primitive FFI type (though it is | not a "basic" type as defined by the FFI). We don't want to know that on | some system it is Int32 and on others it is Int64. We do not want access | to the constructor here. Trouble is, there are a zillion types in Foreign.C.Types, and another zillion in Foreign.Posix.Types. Do you want to list them all as "blessed" in the FFI addendum? S