#15245: Data family promotion is possible -------------------------------------+------------------------------------- Reporter: int-index | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: 8.6.1 Component: Documentation | Version: 8.4.3 Resolution: | Keywords: TypeInType Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by goldfire): According to [https://ghc.haskell.org/trac/ghc/wiki/DependentHaskell/Internal#User- facingdesignissues these mutterings], we need to abstract over a coercion to promote data family instances properly. I haven't paged it all back in, but this is an implementation error, not a documentation one. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/15245#comment:1 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler