#7524: Erroneous repeated kind variable in conflicting type family instance error message ----------------------------------------------+----------------------------- Reporter: goldfire | Owner: Type: bug | Status: new Priority: normal | Component: Compiler Version: 7.7 | Keywords: Os: Unknown/Multiple | Architecture: Unknown/Multiple Failure: Incorrect warning at compile-time | Blockedby: Blocking: | Related: #7587 ----------------------------------------------+----------------------------- Comment(by simonpj@…): commit a98e51ecf51d1a93d48a8a10d35827edfd9d8c28 {{{ Author: Simon Peyton Jones Date: Mon Jan 28 08:18:28 2013 +0000 More refactoring of FamInst/FamInstEnv; finally fixes Trac #7524 Quite a bit of tidying up here; the fix to #7524 is actually only a small part. * Be fully clear that the cab_tvs in a CoAxBranch are not fresh. See Note [CoAxBranch type variables] in CoAxiom. * Use CoAxBranch to replace the ATDfeault type in Class. CoAxBranch is perfect here. This change allowed me to delete quite a bit of boilerplate code, including the corresponding IfaceSynType. * Tidy up the construction of CoAxBranches, and when FamIntBranch is freshened. The latter onw happens only in FamInst.newFamInst. * Tidy the tyvars of a CoAxBranch when we build them, done in FamInst.mkCoAxBranch. See Note [Tidy axioms when we build them] in that module. This is what fixes #7524. Much niceer now. compiler/iface/BinIface.hs | 7 - compiler/iface/IfaceSyn.lhs | 31 ++--- compiler/iface/MkIface.lhs | 21 +-- compiler/iface/TcIface.lhs | 29 ++--- compiler/typecheck/FamInst.lhs | 142 ++++++++++++++------- compiler/typecheck/TcGenGenerics.lhs | 9 +- compiler/typecheck/TcInstDcls.lhs | 50 +++----- compiler/typecheck/TcRnDriver.lhs | 4 +- compiler/typecheck/TcTyClsDecls.lhs | 21 ++-- compiler/types/Class.lhs | 20 +--- compiler/types/CoAxiom.lhs | 31 ++++- compiler/types/Coercion.lhs | 1 - compiler/types/FamInstEnv.lhs | 106 +--------------- compiler/vectorise/Vectorise/Generic/PAMethods.hs | 4 +- compiler/vectorise/Vectorise/Generic/PData.hs | 10 +- 15 files changed, 204 insertions(+), 282 deletions(-) }}} -- Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/7524#comment:2 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler