#11795: Performance issues with replicateM_ -------------------------------------+------------------------------------- Reporter: snoyberg | Owner: snoyberg Type: bug | Status: new Priority: normal | Milestone: Component: libraries/base | Version: 7.10.3 Resolution: | Keywords: Operating System: MacOS X | Architecture: x86_64 Type of failure: Runtime | (amd64) performance bug | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by snoyberg): Actually, it would appear that Ben already modified the implementation of `replicateM_` to something different than I saw: {{{#!hs replicateM_ 0 _ = pure () replicateM_ n x = x *> replicateM_ (pred n) x }}} The implementation I've given here still seems to perform better, due to usage of the worker/wrapper transform. It also keeps the semantics of the current version in GHC 7.10.3 for negative values. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11795#comment:4 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler