#13104: runRW# ruins join points -------------------------------------+------------------------------------- Reporter: lukemaurer | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.1 Resolution: | Keywords: JoinPoints Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by nomeata): Where does this occurence of `runRW#` come from? Before adding hacks to the simplifier, it might be sufficient to eta- expand the argument there. For example, instead of {{{ runST (ST st_rep) = case runRW# st_rep of (# _, a #) -> a }}} write {{{ runST (ST st_rep) = case runRW# (\s. st_rep s) of (# _, a #) -> a }}} or, for good measure, {{{ runST (ST st_rep) = case runRW# (oneShot (\s. st_rep s)) of (# _, a #) -> a }}} Have you tried that? -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/13104#comment:1 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler