Experimental parser: cleanup switch generation

tools/lexer_generator/code_generator.py

 # Copyright 2013 the V8 project authors. All rights reserved.
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 #       notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
 #       copyright notice, this list of conditions and the following
 #       disclaimer in the documentation and/or other materials provided
@@ skipping 146 matching lines @@
         distinct_keys += r[1] - r[0] + 1
         ranges += 1
       else:
         raise Exception()
     if distinct_keys <= 7 or float(distinct_keys)/float(ranges) >= 7.0:
       return split_count
     switch_transitions = []
     if_transitions = []
     for (ranges, node_id) in state['transitions']:
       i = []
+      s = []
       for r in ranges:
         if r[0] == 'CLASS':
           i.append(r)
         else:
-          for x in range(r[1][0], r[1][1] + 1):
-            switch_transitions.append((x, node_id))
+          s.append(r[1])
       if i:
         if_transitions.append((i, node_id))
+      if s:
+        switch_transitions.append((s, node_id))
     state['transitions'] = if_transitions
     state['switch_transitions'] = switch_transitions
     return split_count + 1
 
   def __canonicalize_traversal(self):
     dfa_states = []
     self.__dfa.visit_all_states(lambda state, acc: dfa_states.append(state))
     dfa_states = map(CodeGenerator.__transform_state, dfa_states)
     id_map = {x['original_node_number'] : x for x in dfa_states}
     CodeGenerator.__compute_depths(self.__start_node_number, 1, id_map)
@@ skipping 38 matching lines @@
     template_env = jinja2.Environment(
       loader = jinja2.PackageLoader('lexer_generator', '.'),
       undefined = jinja2.StrictUndefined)
     template = template_env.get_template('code_generator.jinja')
 
     return template.render(
       start_node_number = 0,
       debug_print = self.__debug_print,
       default_action = default_action,
       dfa_states = dfa_states)