#10595: BuiltinRules override other rules in some cases. -------------------------------------+------------------------------------- Reporter: gjsimms | Owner: Type: bug | Status: new Priority: high | Milestone: Component: Compiler | Version: 7.11 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: None/Unknown | Unknown/Multiple Blocked By: | Test Case: Related Tickets: | Blocking: | Differential Revisions: -------------------------------------+------------------------------------- Comment (by gjsimms): I am happy with the workaround/documentation at this point: Just to note, this can be done almost entirely in the Rule system by substituting into temporary functions. So class-methods can be used normally with rewrite rules. {{{ {-# INLINE [1] f' #-} f' = f {-# RULES f = f' #-} {-# RULES (exp1 (f' ...) ...) = exp2) #-} }}} Long term I think it would be most clear if BuiltinRules had no effect on user supplied rewrite rules. This does affect some current libraries e.g. all the RULES in Control.Arrow do nothing, I do not know if/how it affects other libraries. Feel free to close. I do think it is worthwhile making note of in case the simplifier gets overhauled at any point in the future. ida' idb' above can be inlined in the above (all phases) and the rule will still fire for me, I figure this may be somewhat random. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10595#comment:7 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler