#11439: Request for comments: Allow duplicate type signatures -------------------------------------+------------------------------------- Reporter: Iceland_jack | Owner: Type: feature request | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.10.3 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by adamgundry): * cc: adamgundry (added) Comment: I'm not really convinced by the original ticket: couldn't you just as well do something like {{{#!hs sum :: SBool single -> IsSingleton single -> Natural sum STrue = sumTrue sum SFalse = sumFalse sumTrue :: Natural -> Natural sumTrue x = x sumFalse :: [Natural] -> Natural sumFalse [] = 0 sumFalse (x : xs) = x + sumFalse xs }}} without needing any additional syntax or rules for associating duplicate signatures with parts of definitions? On the other hand, being able to declare a bunch of specializations such that GHCi or Haddock can display them does seem rather useful, especially for the kind of very polymorphic code you get in `lens` or the post-FTP Prelude. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11439#comment:4 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler