#7536: Panic with TypeFamilies with type synonym instances -------------------------------+-------------------------------------------- Reporter: snowleopard | Owner: Type: bug | Status: new Priority: normal | Component: Compiler Version: 7.6.1 | Keywords: Os: Unknown/Multiple | Architecture: Unknown/Multiple Failure: Compile-time crash | Blockedby: Blocking: | Related: -------------------------------+--------------------------------------------
Comment(by simonpj@…): commit e89f3bac94f513841f46346528183920783ce1f9 {{{ Author: Simon Peyton Jones <simo...@microsoft.com> Date: Wed Jan 2 08:26:28 2013 +0000 In type or data instances, check that all variables are bound Trac #7536 points out that it's possible for the LHS to *look* as if it binds variables, but does not acutally do so type T a = Int type instance F (T a) = a This patch makes it an error. compiler/typecheck/TcInstDcls.lhs | 43 ++++++++++++++++++----------------- compiler/typecheck/TcMType.lhs | 36 ++++++++++++++++++++++------- compiler/typecheck/TcTyClsDecls.lhs | 23 ++++++------------ 3 files changed, 57 insertions(+), 45 deletions(-) }}} -- Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/7536#comment:2> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler _______________________________________________ Glasgow-haskell-bugs mailing list Glasgow-haskell-bugs@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs