#10711: Defining mapM_ in terms of traverse_ causes substantial blow-up in ByteCodeAsm -------------------------------------+------------------------------------- Reporter: bgamari | Owner: bgamari Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Compile-time | Unknown/Multiple performance bug | Test Case: ghcirun004 Blocked By: | Blocking: Related Tickets: | Differential Revisions: -------------------------------------+------------------------------------- Comment (by nomeata): Another factoid: * It does not help to implement `<$` (used by the default implementation of `*>`) manually. * It does not help to implement `<*>` manually * So `a1 *> a2 = (id <$ a1) <*> a2` indeed seems to be the root of the problem. Do we need to educate people to write `(*>) == (>>)` if they write `(<*>) = ap`? -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10711#comment:8 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler