ru_name :: RuleName, -- and suchlike. It has no free variables.
ru_fn :: Name, -- Name of the Id at
-- the head of this rule
- ru_nargs :: Int, -- Number of args that ru_try expects
+ ru_nargs :: Int, -- Number of args that ru_try expects,
+ -- including type args
ru_try :: [CoreExpr] -> Maybe CoreExpr }
+ -- This function does the rewrite. It given too many
+ -- arguments, it simply discards them; the returned CoreExpr
+ -- is just the rewrite of ru_fn applied to the first ru_nargs args
+ -- See Note [Extra args in rule matching] in Rules.lhs
isBuiltinRule (BuiltinRule {}) = True
isBuiltinRule _ = False