#12428: Allow pattern synonyms to optionally carry coerceability -------------------------------------+------------------------------------- Reporter: dfeuer | Owner: Type: feature request | Status: new Priority: normal | Milestone: 8.2.1 Component: Compiler | Version: 8.0.1 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 dfeuer): Replying to [comment:1 nomeata]:
Can you give a concrete examples? I’m not quite sure what you mean by “carry coerceability”, and how that is tied to pattern synonyms.
Having a newtype constructor in scope in a module brings with it certain `Coercible` instances. There is no other way to bring those into scope globally in a module, although they can be used locally by matching on a `Coercion`. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/12428#comment:2 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler