#11524: Something is amiss with quantification in pattern synonym type signatures -------------------------------------+------------------------------------- Reporter: bgamari | Owner: Type: bug | Status: patch Priority: high | Milestone: 8.0.1 Component: Compiler (Type | Version: 8.0.1-rc1 checker) | Keywords: Resolution: | PatternSynonyms Operating System: Unknown/Multiple | Architecture: Type of failure: GHC rejects | Unknown/Multiple valid program | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Phab:D1879 Wiki Page: | -------------------------------------+------------------------------------- Comment (by Bartosz Nitka <niteria@…>): In [changeset:"07ed24132ebe62aab15f14a655506decdf252ff9/ghc" 07ed2413/ghc]: {{{ #!CommitTicketReference repository="ghc" revision="07ed24132ebe62aab15f14a655506decdf252ff9" Use a correct substitution in tcCheckPatSynDecl The `substTheta` call didn't have the free variables of the `prov_theta` in the `in_scope` set. It should be enough to add `univ_tvs`, as all the `ex_tvs` are already in the domain of the substitution. Test Plan: added a testcase Reviewers: simonpj, bgamari, goldfire, austin Reviewed By: simonpj, bgamari Subscribers: thomie Differential Revision: https://phabricator.haskell.org/D1879 GHC Trac Issues: #11524 }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11524#comment:7> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler