#9398: Data.List.cycle is not a good producer -------------------------------------+------------------------------------- Reporter: dfeuer | Owner: Type: bug | Status: new Priority: normal | Milestone: 7.8.4 Component: | Version: 7.8.3 libraries/base | Keywords: Resolution: | Architecture: Unknown/Multiple Operating System: | Difficulty: Easy (less than 1 Unknown/Multiple | hour) Type of failure: Runtime | Blocked By: performance bug | Related Tickets: Test Case: | Blocking: | Differential Revisions: | -------------------------------------+------------------------------------- Comment (by nomeata): I think you need to move the knot-tying into the argument to build, e.g. something like {{{ cycle xs = build $ \c _ -> let cyc = foldr c cyc xs in cyc }}} (ignoring the issue of `cycle []` for now) It seems that this would be both a good produce, and possibly even a good consumer. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/9398#comment:12 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler