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Why not follow Ross's suggestions in comment 17?

If I understand correctly Ross' proposal is actually independent of this ticket: we could implement it and still have broken RebindableSyntax. That's why I chose to fix the rebindable syntax first. Perhaps then we can

#7828: RebindableSyntax and Arrow ----------------------------------------------+---------------------------- Reporter: AlessandroVermeulen | Owner: Type: bug | jstolarek Priority: normal | Status: new Component: Compiler (Type checker) | Milestone: 7.10.1 Resolution: | Version: 7.6.2 Operating System: Unknown/Multiple | Keywords: Type of failure: GHC rejects valid program | Architecture: Test Case: | Unknown/Multiple Blocking: | Difficulty: Unknown | Blocked By: | Related Tickets: #1537, | #3613 ----------------------------------------------+---------------------------- Comment (by ross): Replying to [comment:27 jstolarek]: think about alternative desugaring of arrow syntax. It's not so much an alternative desugaring as a different view of the existing desugaring in which `do` and `if` can be rebound in an analogous manner to the way they're rebound in the expression world. Or it's a re- interpretation of this ticket: instead of using private versions of `arr`, `>>>` and `first`, the idea is to use private versions of the control operators `bind`, `bind_` and `ifThenElseA`, the arrow counterparts of `>>=`, `>>` and `ifThenElse`. I don't see how the former can work, as each language construct is translated to several of those combinators. In addition, you have less control of the types of these things, because the translation re-arranges and trims the environment it passes through the arrow. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/7828#comment:28 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler