Unfortunatelly I can not :( Look, Vector_testid indicates, that it holds "testid" method (it should be named Vector_method1 instead - sorry for
#8634: Code valid in GHC 7.6 is impossible to move over GHC 7.7 (because of liberal coverage condition) -----------------------------------+--------------------------------------- Reporter: danilo2 | Owner: Type: bug | Status: new Priority: high | Milestone: Component: Compiler | Version: 7.7 Resolution: | Keywords: Operating System: | Architecture: Unknown/Multiple Unknown/Multiple | Difficulty: Unknown Type of failure: None/Unknown | Blocked By: Test Case: | Related Tickets: #1241, #2247, #8356 Blocking: | -----------------------------------+--------------------------------------- Comment (by rwbarton): that typo.
If we get more associated functions, we would have Vector_method2, Vector_method3 etc, so we need to distinguish them - see the sample code in this comment.
That doesn't seem to be a problem, as those will be instances of different classes `Method2`, `Method3`. {{{#!haskell instance (m ~ Vector_method1, out ~ (t1->t1)) => Method1 (Vector a) m out where method1 = (Vector_method1 . testid) instance (m ~ Vector_method2, out ~ (t1->(t1,t1))) => Method2 (Vector a) m out where method2 = (Vector_method2 . testf2) }}} With these changes your second program runs for me with GHC HEAD as long as I comment out `testx`--which is not used in the program. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/8634#comment:4 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler