#15316: Regarding coherence and implication loops in presence of QuantifiedConstraints -------------------------------------+------------------------------------- Reporter: mniip | Owner: (none) Type: bug | Status: new Priority: high | Milestone: 8.6.1 Component: Compiler (Type | Version: 8.5 checker) | Keywords: Resolution: | QuantifiedConstraints Operating System: Unknown/Multiple | Architecture: Type of failure: GHC accepts | Unknown/Multiple invalid program | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by simonpj): I meant: * Apply the instance-termination check to every quantified constraint `(cxt => constraint)` appearing anywhere in a type. So `f :: (Show a => Show a) => blah` would be rejected just as {{{ instance Show a => Show a }}} is rejected -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/15316#comment:5 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler