#2530: deriving Show adds extra parens for constructor with record syntax -------------------------------------+------------------------------------- Reporter: spl | Owner: bgamari Type: bug | Status: new Priority: highest | Milestone: 8.0.1 Component: Compiler | Version: 6.8.3 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Phab:D669 Wiki Page: | -------------------------------------+------------------------------------- Comment (by bgamari): I would be fine with retaining the old behavior, keeping the parens, for now. It's pretty widely believed that the binding of record syntax specified in the report was a mistake. Let's allow the Haskell Prime committee to discuss this matter before we commit to changing `Show`. While it's almost certainly not practical to change the binding of record syntax, the next report could specify a more lax semantics for `Show`. To be clear, I'm merely requesting that the committee add this matter to their list of matters to address; their final decision is of course in their hands. If there is a good chance that the committee will consider such a change, then let's revert the commit in comment:25 for now and reconsider after the committee has made their decision. If it's unlikely that the next report will loosen `Show`, then we should decide now whether we want retain and document the old behavior as an infelicity of GHC's implementation, or whether we want to come into compliance with the Report. I'm slightly leaning towards the former for the sake of stability, although I'm happy to hear arguments in the other direction. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/2530#comment:36 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler