#9773: Binding ImplicitParams in lambda results in parse error -------------------------------------+------------------------------------- Reporter: | Owner: SimonHengel | Status: closed Type: bug | Milestone: Priority: normal | Version: 7.8.3 Component: Compiler | Keywords: (Parser) | Architecture: Unknown/Multiple Resolution: invalid | Difficulty: Unknown Operating System: | Blocked By: Unknown/Multiple | Related Tickets: Type of failure: GHC | rejects valid program | Test Case: | Blocking: | Differential Revisions: | -------------------------------------+------------------------------------- Comment (by SimonHengel): As I understand it I have to explicitly bind an implicit parameter somewhere to bring it "into scope". At least intuitively I would assume that if {{{ forM_ [1..3] $ \ bar -> let ?bar = bar in foo }}} works, then {{{ forM_ [1..3] $ \ ?bar -> let ?bar = bar in foo }}} should work too. But I realize that the current behavior is clearly laid out in the User's Guide. So it's certainly not a bug, but (if anything) a feature request. Are there any fundamental limitations that would prevent us to make this work? -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/9773#comment:2 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler