#10845: Incorrect behavior when let binding implicit CallStack object -------------------------------------+------------------------------------- Reporter: nitromaster101 | Owner: gridaphobe Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.11 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: #10846 | Differential Rev(s): Phab:D1422 Wiki Page: | -------------------------------------+------------------------------------- Comment (by simonpj): (I think you are referring to my second version, post-wrinkle.) You are right. I was hi-jacking `IPOccOrigin` to do "combine and default to empty stack". But yes, I think we can allow it ''not'' to add a location on its own behalf. If you wanted the current effect of `?loc`, you can always get the same effect by using {{{ currentLoc :: ?loc :: Location => Location currentLoc = ?loc }}} We'd better document this carefully though. Simon -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10845#comment:15 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler