#12001: RFC: Add pattern synonyms to base -------------------------------------+------------------------------------- Reporter: Iceland_jack | Owner: Type: feature request | Status: new Priority: normal | Milestone: Component: libraries/base | 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: | -------------------------------------+------------------------------------- Comment (by Iceland_jack): Since `Polar` was the pick of the litter, it's worth mentioning that with record syntax: {{{#!hs pattern Polar :: RealFloat a => a -> a -> Complex a pattern Polar {m, theta} <- (polar -> (m, theta)) where Polar m theta = mkPolar m theta }}} we can write {{{ ghci> (3 :+ 1) { m = 2 } 1.8973665961010275 :+ 0.6324555320336759 ghci> ghci> set (_polar._1) 2 (3 :+ 1) 1.8973665961010275 :+ 0.6324555320336759 }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/12001#comment:6 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler