surely the intention of the MINIMAL pragma was to warn if we end up with
#10959: MINIMAL pragma and default implementations -------------------------------------+------------------------------------- Reporter: basvandijk | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.10.2 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: Other | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by simonpj): the meth = error "..." implementation that the compiler would supply if there was no other implementation at all Not only that. Bur also {{{ class Eq a where (==), (/=) :: a -> a -> Bool (==) a b = not (a /= b) (/=) a b = not (a == b) }}} Here we have code for both `(==)` and `(/=)` (no `error` here), but the MINIMAL pragma allows you to say that you should supply a "real" implementation for one or the other. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10959#comment:7 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler