import Coercion ( coercionKind )
import TcType ( tcSplitTyConApp_maybe )
import CoreTidy ( tidyRules )
-import Id ( Id, idUnfolding, isLocalId, isGlobalId, idName, idType,
- idSpecialisation, idCoreRules, setIdSpecialisation )
+import Id
import IdInfo ( SpecInfo( SpecInfo ) )
import Var ( Var )
import VarEnv
-- It's only a one-way match; unlike instance matching we
-- don't consider unification
--
--- Notice that there is no case
--- ruleCantMatch (Just n1 : ts) (Nothing : as) = True
--- Reason: a local variable 'v' in the actuals might
--- have an unfolding which is a global.
--- This quite often happens with case scrutinees.
+-- Notice that [_$_]
+-- ruleCantMatch [Nothing] [Just n2] = False
+-- Reason: a template variable can be instantiated by a constant
+-- Also:
+-- ruleCantMatch [Just n1] [Nothing] = False
+-- Reason: a local variable 'v' in the actuals might [_$_]
+
ruleCantMatch (Just n1 : ts) (Just n2 : as) = n1 /= n2 || ruleCantMatch ts as
ruleCantMatch (t : ts) (a : as) = ruleCantMatch ts as
ruleCantMatch ts as = False
-- (b) rules added in subsequent modules (extra_rules)
-- PrimOps, for example, are born with a bunch of rules under (a)
getRules rule_base fn
- | isLocalId fn = idCoreRules fn
- | otherwise = WARN( null (idCoreRules fn), ppr fn <+> ppr (idCoreRules fn) )
- lookupNameEnv rule_base (idName fn) `orElse` []
+ | isLocalId fn = idCoreRules fn
+ | otherwise = WARN( not (isPrimOpId fn) && notNull (idCoreRules fn),
+ ppr fn <+> ppr (idCoreRules fn) )
+ idCoreRules fn ++ (lookupNameEnv rule_base (idName fn) `orElse` [])
+ -- Only PrimOpIds have rules inside themselves, and perhaps more besides
matchRules :: (Activation -> Bool) -> InScopeSet
-> Id -> [CoreExpr]
findBest target (rule1,ans1) ((rule2,ans2):prs)
| rule1 `isMoreSpecific` rule2 = findBest target (rule1,ans1) prs
| rule2 `isMoreSpecific` rule1 = findBest target (rule2,ans2) prs
-#ifdef DEBUG
- | otherwise = let pp_rule rule
+ | debugIsOn = let pp_rule rule
| opt_PprStyle_Debug = ppr rule
| otherwise = doubleQuotes (ftext (ru_name rule))
in pprTrace "Rules.findBest: rule overlap (Rule 1 wins)"
(vcat [if opt_PprStyle_Debug then
- ptext SLIT("Expression to match:") <+> ppr fn <+> sep (map ppr args)
+ ptext (sLit "Expression to match:") <+> ppr fn <+> sep (map ppr args)
else empty,
- ptext SLIT("Rule 1:") <+> pp_rule rule1,
- ptext SLIT("Rule 2:") <+> pp_rule rule2]) $
+ ptext (sLit "Rule 1:") <+> pp_rule rule1,
+ ptext (sLit "Rule 2:") <+> pp_rule rule2]) $
findBest target (rule1,ans1) prs
-#else
| otherwise = findBest target (rule1,ans1) prs
-#endif
where
(fn,args) = target
check_rule rule = rule_herald rule <> colon <+> rule_info rule
rule_herald (BuiltinRule { ru_name = name })
- = ptext SLIT("Builtin rule") <+> doubleQuotes (ftext name)
+ = ptext (sLit "Builtin rule") <+> doubleQuotes (ftext name)
rule_herald (Rule { ru_name = name })
- = ptext SLIT("Rule") <+> doubleQuotes (ftext name)
+ = ptext (sLit "Rule") <+> doubleQuotes (ftext name)
rule_info rule
| Just _ <- matchRule noBlackList emptyInScopeSet args rough_args rule