#3699: Wildcards in type functions -------------------------------------+------------------------------------- Reporter: | Owner: MartijnVanSteenbergen | Status: new Type: feature request | Milestone: 7.12.1 Priority: low | Version: 6.10.4 Component: Compiler (Type | Keywords: newcomer checker) | Architecture: Resolution: | Unknown/Multiple Operating System: Unknown/Multiple | Test Case: Type of failure: None/Unknown | Blocking: Blocked By: | Differential Revisions: Related Tickets: | -------------------------------------+------------------------------------- Comment (by jstolarek): I always imagined that `_` will be instantiated internally to a fresh type variable. This means that this feature would mostly affect the parser and renamer and by the time you reach the point when your example collision is checked (`FamInst.checkForConflicts`, called from `FamInst.checkFamInstConsistency`) the example code will look like: {{{#!hs type instance Testing (f :>: a_1234) = MyType f type instance Testing (a_5678 :>: g) = MyType g }}} where `a_1234` and `a_5678` are fresh type variables. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/3699#comment:15 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler