Experimental parser: handling unique keys in merges

tools/lexer_generator/rule_parser.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 69 matching lines @@
              | empty'''
 
   def p_state_change(self, p):
     'state_change : GRAPH_OPEN IDENTIFIER GRAPH_CLOSE'
     state = self.__state
     state.current_state = p[2]
     assert state.current_state
     if not state.current_state in state.rules:
       state.rules[state.current_state] = {
         'default_action': None,
-        'catch_all' : None,
+        'uniques' : {},
         'regex' : []
       }
     p[0] = state.current_state
 
   def p_transition_rules(self, p):
     '''transition_rules : transition_rule transition_rules
                         | empty'''
 
   def p_transition_rule(self, p):
     '''transition_rule : composite_regex action
                        | DEFAULT_ACTION default_action
                        | CATCH_ALL action'''
     precedence = RuleParser.__rule_precedence_counter
     RuleParser.__rule_precedence_counter += 1
     action = p[2]
     (entry_action, match_action, transition) = action
     if transition and not transition in self.__keyword_transitions:
       assert not transition == 'default', "can't append default graph"
       self.__state.transitions.add(transition)
     rules = self.__state.rules[self.__state.current_state]
     if p[1] == 'default_action':
       assert self.__state.current_state == 'default'
       assert not rules['default_action']
       rules['default_action'] = action
     elif p[1] == 'catch_all':
-      assert not rules['catch_all']
-      rules['catch_all'] = (precedence, action)
+      assert p[1] not in rules['uniques']
+      rules['uniques'][p[1]] = True
+      rules['regex'].append((NfaBuilder.unique_key(p[1]), precedence, action))
     else:
       regex = p[1]
       rules['regex'].append((regex, precedence, action))
 
   def p_action(self, p):
     '''action : ACTION_OPEN maybe_identifier_action OR maybe_identifier_action OR maybe_transition ACTION_CLOSE'''
     p[0] = (p[2], p[4], p[6])
 
   def p_default_action(self, p):
     'default_action : ACTION_OPEN identifier_action ACTION_CLOSE'
@@ skipping 182 matching lines @@
         if not transition:
           pass
         elif transition == 'continue':
           assert not subgraph == 'default'
           graph = NfaBuilder.add_continue(graph)
         else:
           assert subgraph == 'default'
           graph = NfaBuilder.join_subgraph(
             graph, transition, rule_map[transition])
         graphs.append(graph)
-      if v['catch_all']:
-        (precedence, catch_all) = v['catch_all']
-        assert catch_all == (None, None, 'continue'), "unimplemented"
-        graphs.append(NfaBuilder.add_continue(NfaBuilder.catch_all()))
       graph = NfaBuilder.or_graphs(graphs)
       rule_map[subgraph] = graph
     # process first the subgraphs, then the default graph
     for k, v in parser_state.rules.items():
       if k == 'default': continue
       process(k, v)
     process('default', parser_state.rules['default'])
     # build the automata
     for rule_name, graph in rule_map.items():
       self.__automata[rule_name] = RuleProcessor.Automata(builder, graph)
       self.__rule_trees[rule_name] = graph
     # process default_action
     default_action = parser_state.rules['default']['default_action']
     self.default_action = Action(None, default_action[1]) if default_action else None