#14052: Significant GHCi speed regression with :module and `let` in GHC 8.2.1 -------------------------------------+------------------------------------- Reporter: RyanGlScott | Owner: osa1 Type: bug | Status: new Priority: high | Milestone: 8.4.2 Component: GHCi | Version: 8.2.1-rc2 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Runtime | Unknown/Multiple performance bug | Test Case: Blocked By: | Blocking: Related Tickets: #11547 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by simonpj):
I think regardless of the performance problems, #11547 (​Phab:D2447) should just be reverted.
Reviewing this, I agree with you. I see that in my original review of Phab:D2447 I wrote "I don't think I fully understand all the consequences, but I don't want to stand in the way". This ticket shows some bad consequences. And I don't think anyone is actively arguing for access to previously in-scope versions of `x`. It'd be polite to tell the original author of the patch ([https://phabricator.haskell.org/p/mniip/ mniip] I believe), in case he has reasons for wanting (some revised version of) his patch. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14052#comment:17 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler