Source::TreeRewriter: Simplify callback interface and avoid Method allocation

Author: marcandre

lib/parser/source/tree_rewriter.rb

@@ -109,11 +109,10 @@ def initialize(source_buffer,
         @different_replacements = check_policy_value(different_replacements)
         @swallowed_insertions = check_policy_value(swallowed_insertions)
 
-        @enforcer = method(:enforce_policy)
         # We need a range that would be jugded as containing all other ranges,
         # including 0...0 and size...size:
         all_encompassing_range = @source_buffer.source_range.adjust(begin_pos: -1, end_pos: +1)
-        @action_root = TreeRewriter::Action.new(all_encompassing_range, @enforcer)
+        @action_root = TreeRewriter::Action.new(all_encompassing_range, self)
       end
 
       ##
@@ -354,6 +353,16 @@ def insert_after_multi(range, text)
 
       extend Deprecation
 
+      ##
+      # @api private
+      # reserved for TreeAction
+      #
+      def enforce_policy(event)
+        return if policy(event) == :accept
+        return unless (values = yield)
+        trigger_policy(event, **values)
+      end
+
       protected
 
       attr_reader :action_root
@@ -369,7 +378,7 @@ def check_policy_value(value)
 
       def combine(range, attributes)
         range = check_range_validity(range)
-        action = TreeRewriter::Action.new(range, @enforcer, **attributes)
+        action = TreeRewriter::Action.new(range, self, **attributes)
         @action_root = @action_root.combine(action)
         self
       end
@@ -393,12 +402,6 @@ def policy(event)
         instance_variable_get(EVENT_TO_POLICY.fetch(event))
       end
 
-      def enforce_policy(event)
-        return if policy(event) == :accept
-        return unless (values = yield)
-        trigger_policy(event, **values)
-      end
-
       POLICY_TO_LEVEL = {warn: :warning, raise: :error}.freeze
       def trigger_policy(event, range: raise, conflict: nil, **arguments)
         action = policy(event)

lib/parser/source/tree_rewriter/action.rb

@@ -206,7 +206,7 @@ def check_fusible(action, *fusible)
         return if fusible.empty?
         fusible.each do |child|
           kind = action.insertion? || child.insertion? ? :crossing_insertions : :crossing_deletions
-          @enforcer.call(kind) { {range: action.range, conflict: child.range} }
+          @enforcer.enforce_policy(kind) { {range: action.range, conflict: child.range} }
         end
         fusible
       end
@@ -222,15 +222,15 @@ def merge(action)
       end
 
       def call_enforcer_for_merge(action)
-        @enforcer.call(:different_replacements) do
+        @enforcer.enforce_policy(:different_replacements) do
           if @replacement && action.replacement && @replacement != action.replacement
             {range: @range, replacement: action.replacement, other_replacement: @replacement}
           end
         end
       end
 
       def swallow(children)
-        @enforcer.call(:swallowed_insertions) do
+        @enforcer.enforce_policy(:swallowed_insertions) do
           insertions = children.select(&:insertion?)
 
           {range: @range, conflict: insertions.map(&:range)} unless insertions.empty?