#14880: GHC panic: updateRole -------------------------------------+------------------------------------- Reporter: RyanGlScott | Owner: goldfire Type: bug | Status: new Priority: normal | Milestone: 8.8.1 Component: Compiler (Type | Version: 8.2.2 checker) | Resolution: | Keywords: TypeInType Operating System: Unknown/Multiple | Architecture: Type of failure: Compile-time | Unknown/Multiple crash or panic | Test Case: Blocked By: | Blocking: Related Tickets: #15076 | Differential Rev(s): Phab:D4769 Wiki Page: | -------------------------------------+------------------------------------- Comment (by goldfire): I have two takeaways from this: - An accumulator style is the Right Way to go when building up a set. This idea should probably be abstracted over right in the `VarSet` interface. But do we get these gains without eta-expanding everything? (See Note [FV eta expansion] in FV.) - The extra work to track order has no effect. I find this surprising, but not overly so, because we can avoid the extra work via laziness. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14880#comment:94 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler