#9880: ghc crashes on th splices in instance context -------------------------------------+------------------------------------- Reporter: Philonous | Owner: Type: bug | Status: closed Priority: normal | Milestone: Component: Documentation | Version: 7.8.3 Resolution: fixed | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by mentheta): Replying to [comment:2 goldfire]:
The behavior you see -- that error -- is what I'd expect.
I had a brief go at implementing local declaration splices but soon realized that implementing this involves quite a bit of replumbing. The splices would have to break up mutually-recursive groups within class, instance, and `let` declarations, and that would require changes to several bits of HsSyn. So, I settled for just fixing the panic and waiting for someone to scream loudly that they need this feature.
Hello goldfire, I've just run into the situation where I hoped `Q [Dec]` would have worked in a let binding, and it did not. I don't yet intend to scream, however, I am curious; Is there any Trac ticket in particular I could subscribe to, where I can follow any potential development on the implementation for supporting declaration splices in let bindings? -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/9880#comment:7 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler