#5927: A type-level "implies" constraint on Constraints -------------------------------------+------------------------------------- Reporter: illissius | Owner: (none) Type: feature request | Status: closed Priority: normal | Milestone: Component: Compiler (Type | Version: 7.4.1 checker) | Keywords: Resolution: duplicate | QuantifiedConstraints Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: #2893 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by RyanGlScott): * status: new => closed * resolution: => duplicate * related: => #2893 Comment: The "`Implies`" in {{{(c `Implies` Show)}}} is the `=>` in the quantified constraint `(c => Show)`. Quantified constraints also allow you to write `forall a. Monoid a`. Or, to put things another way, this is a duplicate of #2893, which tracks the implementation of `QuantifiedConstraints`. I'll close this ticket in favor of that one. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/5927#comment:30 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler