#8767: Add rules involving `coerce` to the libraries -------------------------------------------------+------------------------- Reporter: nomeata | Owner: Type: task | Status: new Priority: normal | Milestone: 7.8.1 Component: libraries/base | Version: Resolution: | 7.8.1-rc2 Operating System: Unknown/Multiple | Keywords: Type of failure: None/Unknown | Architecture: Test Case: | Unknown/Multiple tests/simplCore/should_run/T2110.hs | Difficulty: Blocking: | Unknown | Blocked By: 8718 | Related Tickets: #2110 -------------------------------------------------+------------------------- Comment (by nomeata): I still believe that people should be free to write non-law-abiding instances (or maybe law-abiding up to some interface), and the compiler should not interfere with that. We should simply suggest them to add a `fmap coerce = coerce` rule for their particular fmap if they care. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/8767#comment:9 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler