#12698: GHC panic on pattern synonym -------------------------------------+------------------------------------- Reporter: Iceland_jack | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.1 Resolution: | Keywords: | PatternSynonyms 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 Simon Peyton Jones <simonpj@…>): In [changeset:"a693d1cb0ee9499af3145d73b1aebe5b6df0da98/ghc" a693d1cb/ghc]: {{{ #!CommitTicketReference repository="ghc" revision="a693d1cb0ee9499af3145d73b1aebe5b6df0da98" Correct order of existentials in pattern synonyms Trac #12698 exposed a nasty bug in the typechecking for pattern synonmys: the existential type variables weren't being put in properly-scoped order. For some reason TcPatSyn.tcCollectEx was colleting them as a set, not as a list! Easily fixed. }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12698#comment:2> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler