Upon further inspection, we're not really doing this. The first type
#8583: Associated pattern synonyms -------------------------------------+------------------------------------- Reporter: cactus | Owner: Type: feature request | Status: new Priority: normal | Milestone: Component: Compiler | Version: Resolution: | Keywords: | PatternSynonyms Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: 5144 | Blocking: Related Tickets: | Differential Rev(s): -------------------------------------+------------------------------------- Comment (by nomeata): parameter to Nil and Cons are inputs This seems to be #9671 in disguise. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/8583#comment:8 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler