#14119: Refactor type patterns -------------------------------------+------------------------------------- Reporter: goldfire | Owner: (none) Type: task | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.2.1 Resolution: | Keywords: TypeInType Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: 12564, 13910, | 13938, 14038 Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by goldfire): It's true that there's no counterpart to `Expr`, but perhaps there could be. The problem is that it wouldn't pay its way: the only real usage for the pattern type would be in RULEs. In types, though, patterns come up more often, perhaps tilting the needle enough. Another way of examining this: pattern-matches in terms are elaborately desugared into nested cases. If they weren't, the case for an expression- level pattern type would be stronger. And in types, we don't do this desugaring. On the other hand, there is my sentiment in comment:1. I don't think I'd argue with "Well, that's a good idea, but not worth it since we'll be doing much heavier refactoring soon, anyway." -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14119#comment:7 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler