#15354: QuantifiedConstraints not fully described in manual -------------------------------------+------------------------------------- Reporter: goldfire | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: 8.6.1 Component: Documentation | Version: 8.5 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by AntC): Replying to [comment:1 Simon Peyton Jones <simonpj@…>]:
{{{ This is a documentation-only fix, addressing Trac #15354. }}}
Thanks Simon, is there a typo? {{{ class ::= ... | [forall tyavrs .] [context =>] qtycls inst1 ... instn | [forall tyavrs .] [context =>] tyvar inst1 ... instn }}} should be `| [forall tyvars .] ...`? (I think this has come through from the github proposal.) So to know if some code is using `QuantifiedConstraints`: either there's a `context =>` or a `forall` (or both). If neither appear (despite having `{-# LANGUAGE QuantifiedConstraints #-}`), then it's a regular class appearing in a context, whatever "regular" means ;-). -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/15354#comment:2> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler