#11555: catch _|_ breaks at -O1 -------------------------------------+------------------------------------- Reporter: slyfox | Owner: Type: bug | Status: new Priority: highest | Milestone: 8.0.1 Component: Compiler | Version: 8.0.1-rc2 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Incorrect result | Unknown/Multiple at runtime | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by NeilMitchell): I talked to Simon offline a few days ago, after that I believe his opinion was: * {{{catch#}}} should remain strict in it's first argument. * {{{catch a b = catch# (lazy a) b}}} is the correct way to express the laziness, the {{{evaluate}}} trick certainly avoids the problem for now, but it may not be robust in the future. * There are places in the IO subsystem which get a significant benefit from a strict catch, they should use a more primitive version ({{{strictCatch}}} or something). * The default exposed {{{catch}}} (and also {{{try}}}, {{{handle}}} etc) should use {{{lazy}}}. All these functions seem to share the same underlying entry point, so that shouldn't be hard. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11555#comment:11 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler