#2110: Rules to eliminate casted id's -------------------------------------+------------------------------------ Reporter: igloo | Owner: Type: feature request | Status: new Priority: lowest | Milestone: 7.6.2 Component: Compiler | Version: 6.8.2 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Unknown/Multiple Type of failure: None/Unknown | Difficulty: Unknown Test Case: | Blocked By: Blocking: | Related Tickets: -------------------------------------+------------------------------------ Comment (by nomeata): Alternative, similar idea: Leave the RULE as it is, but be smart when matching `(GHC.Prim.coerce @ t @ t1 $dCoercible)` and if the expression is of the form {{{(\x -> x) `cast` c}}}, succeed with a substitution `$dCoercible = MkCoercion @ t1 @ t2 @~ c`. The RHS would then look a bit convoluted, but the simplifier surely cleans that up. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/2110#comment:37 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler