#13733: Simplify constraints on RULES LHS -------------------------------------+------------------------------------- Reporter: nomeata | Owner: (none) Type: feature request | Status: new Priority: normal | Milestone: Component: Compiler | Version: 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): Wiki Page: | -------------------------------------+------------------------------------- Comment (by simonpj):
user cannot even specify the desired rule,
Certainly you can! {{{ isntance Eq T where (==) = eqT eqT :: T -> T -> T {-# NOINLINE [1] eqT #-} {-# RULES eqT x x = True #-} }}} All fine! I have no clear understanding of what you are proposing. Perhaps you can lay it out? What's wrong with the approach I suggest? It seems simple and direct. Really the only thing that's tricky here is that the "class-op rules" are built-in so you can't control their competition with rules you want to write. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/13733#comment:3 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler