do not create memo objects since we'll just throw them away

actionpack/lib/action_dispatch/journey/gtg/simulator.rb

@@ -19,6 +19,14 @@ module ActionDispatch
         end
 
         def simulate(string)
+          ms = memos(string) { return }
+          MatchData.new(ms)
+        end
+
+        alias :=~    :simulate
+        alias :match :simulate
+
+        def memos(string)
           input = StringScanner.new(string)
           state = [0]
           while sym = input.scan(%r([/.?]|[^/.?]+))
@@ -29,15 +37,10 @@ module ActionDispatch
             tt.accepting? s
           }
 
-          return if acceptance_states.empty?
+          return yield if acceptance_states.empty?
 
-          memos = acceptance_states.flat_map { |x| tt.memo(x) }.compact
+          acceptance_states.flat_map { |x| tt.memo(x) }.compact
-
-          MatchData.new(memos)
         end
-
-        alias :=~    :simulate
-        alias :match :simulate
       end
     end
   end

actionpack/lib/action_dispatch/journey/router.rb

@@ -121,8 +121,7 @@ module ActionDispatch
 
         def filter_routes(path)
           return [] unless ast
-          data = simulator.match(path)
+          simulator.memos(path) { [] }
-          data ? data.memos : []
         end
 
         def find_routes env