#10830: maximumBy has a space leak -------------------------------------+------------------------------------- Reporter: NeilMitchell | Owner: Type: bug | Status: new Priority: high | Milestone: 8.2.1 Component: Core Libraries | Version: 7.10.2 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Runtime | Unknown/Multiple performance bug | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Phab:D1205 Wiki Page: | -------------------------------------+------------------------------------- Comment (by ekmett): I'm okay with switching `maximumBy` and `minimumBy` to `foldl1` for now. This would at least fix the stack space regression relative to the original `[]` implementation. It'd be a big step in the right direction from the status quo. If ''later on'' we can come up with a `foldMap'` or similar alternative with palatable semantics we can switch over to that and we should be able to retain the stack benefits. This would buy us time to fiddle with the semantics and implementation of such a combinator and see how well it can optimize. Breaking up the fix like this would avoid letting the quest for the perfect solution derail us from fixing an annoying regression in a common combinator today, and even if the second stage never happened this path would still make most consumers happy. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10830#comment:28 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler