GHCi with +t option set shows type representations

hvr reported this morning that defining a data type in GHCi with the show types (:set +t) option set results in additional unexpected output. For instance,

$ inplace/bin/ghc-stage2 --interactive
GHCi, version 7.11.20151101: http://www.haskell.org/ghc/  :? for help
Prelude> :set +t
Prelude> data Hi
$tcHi :: TyCon
$trModule :: Module
data Hi
Prelude>

The $tcHi and $trModule bindings are details of the Typeable implementation introduced in D1404 and should likely be hidden from the user.

This would be trivial to fix in InteractiveUI.printTypeOfNames except for the fact that we currently have no way to identify this sort of Name. In fact any knowledge that the name was generated appears to have been thrown away as early as OccName.mkTyConRepSysOcc.

Edited Mar 10, 2019 by Ben Gamari

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