#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): -------------------------------------+------------------------------------- Comment (by gridaphobe): Hrm, unfortunately splitting off the wanted IP constraints in `simplifyInfer` doesn't work because we need them to infer a corresponding given. For example, in {{{#!haskell f :: (?x :: Int) => Int f = let y = ?x in y }}} we want to infer `y :: (?x :: Int) => Int` (according to the Note "Inheriting Implicit Parameters"). But with CallStack IPs, {{{#!haskell f :: (?x :: CallStack) => [(String, SrcLoc)] f = let y = getCallStack ?x in y }}} we want to infer `y :: [(String, SrcLoc)]`. We really '''don't''' want to infer a CallStack IP here because that would add an extra location to the stack. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10845#comment:7 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler