#11523: Infinite Loop when mixing UndecidableSuperClasses and the class/instance constraint synonym trick. -------------------------------------+------------------------------------- Reporter: ekmett | Owner: Type: bug | Status: new Priority: highest | Milestone: 8.0.1 Component: Compiler (Type | Version: 8.0.1-rc1 checker) | Keywords: Resolution: | UndecidableSuperClasses Operating System: Unknown/Multiple | Architecture: Type of failure: GHC rejects | Unknown/Multiple valid program | Test Case: Blocked By: | Blocking: Related Tickets: #11480 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by Simon Peyton Jones <simonpj@…>): In [changeset:"8871737db588b1cb8f7d33d60c5af80b85b2422d/ghc" 8871737/ghc]: {{{ #!CommitTicketReference repository="ghc" revision="8871737db588b1cb8f7d33d60c5af80b85b2422d" Document and improve superclass expansion When investigating Trac #11523 I found that superclass expansion was a little over-aggressive; we were sort of unrolling each loop twice. This patch corrects that, and adds explanatory comments. }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11523#comment:4> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler