#14386: GHC doesn't allow Coercion between partly-saturated type constructors -------------------------------------+------------------------------------- Reporter: Iceland_jack | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.3 Resolution: | Keywords: roles Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: #14317 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by RyanGlScott): * related: => #14317 Comment: I think ultimately this ties back to GHC's inability to eta-reduce the unwrapping rule: {{{#!hs Coercible (Op cat a b) (cat b a) }}} In other words, it's the same symptom as in https://ghc.haskell.org/trac/ghc/ticket/14317#comment:6. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14386#comment:7 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler