Re: [GHC] #11334: GHC panic when calling typeOf on a promoted data constructor

#11334: GHC panic when calling typeOf on a promoted data constructor -------------------------------------+------------------------------------- Reporter: RyanGlScott | Owner: Type: bug | Status: new Priority: high | Milestone: 8.0.1 Component: Compiler (Type | Version: 8.0.1-rc1 checker) | Resolution: | Keywords: TypeInType Operating System: Unknown/Multiple | Architecture: Type of failure: Compile-time | Unknown/Multiple crash | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Phab:D1757 Wiki Page: | -------------------------------------+------------------------------------- Comment (by Ben Gamari ): In [changeset:"65b810bdda625f2e98069c2c56ec93e1c65667a6/ghc" 65b810b/ghc]: {{{ #!CommitTicketReference repository="ghc" revision="65b810bdda625f2e98069c2c56ec93e1c65667a6" Show TYPE 'Lifted/TYPE 'Unlifted as */# in Show TypeRep instance Kind equalities changed how `*`/`#` are represented internally, which means that showing a `TypeRep` that contains either of those kinds produces a rather gross-looking result, e.g., ```

typeOf (Proxy :: Proxy 'Just) Proxy (TYPE 'Lifted -> Maybe (TYPE 'Lifted)) 'Just

We can at least special-case the `Show` instance for `TypeRep` so that
it prints `*` to represent `TYPE 'Lifted` and `#` to represent `TYPE
'Unlifted`.

Addresses one of the issues uncovered in #11334.

Test Plan: ./validate

Reviewers: simonpj, hvr, austin, goldfire, bgamari

Reviewed By: bgamari

Subscribers: thomie

Differential Revision: https://phabricator.haskell.org/D1757

GHC Trac Issues: #11334
}}}

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11334#comment:6>
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