Experimental parser: simplify goto logic

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 116 matching lines @@
     'default_action : ACTION_OPEN action_part ACTION_CLOSE'
     p[0] = (None, p[2], None)
 
   def p_maybe_action_part(self, p):
     '''maybe_action_part : action_part
                          | empty'''
     p[0] = p[1]
 
   def p_action_part(self, p):
     '''action_part : code
-                         | identifier_action'''
+                   | identifier_action'''
     p[0] = p[1]
 
   def p_maybe_transition(self, p):
     '''maybe_transition : IDENTIFIER
                         | empty'''
     p[0] = p[1]
 
   def p_identifier_action(self, p):
     '''identifier_action : IDENTIFIER
                          | IDENTIFIER LEFT_PARENTHESIS RIGHT_PARENTHESIS
                          | IDENTIFIER LEFT_PARENTHESIS action_params RIGHT_PARENTHESIS'''
     assert p[1] != 'code'
     if len(p) == 2 or len(p) == 4:
       p[0] = (p[1], None)
     elif len(p) == 5:
-      p[0] = (p[1], p[3])
+      if len(p[3]) == 1:
+        p[0] = (p[1], p[3][0])
+      else:
+        p[0] = (p[1], p[3])
     else:
       raise Exception()
 
   def p_action_params(self, p):
     '''action_params : IDENTIFIER
                      | IDENTIFIER COMMA action_params'''
     if len(p) == 2:
-      p[0] = p[1]
+      p[0] = (p[1],)
     elif len(p) == 4:
-      p[0] = (p[1], p[3])
+      p[0] = tuple(([p[1]] + list(p[3])))
     else:
       raise Exception()
 
   def p_composite_regex(self, p):
     '''composite_regex : regex_parts OR regex_parts
                        | regex_parts'''
     if len(p) == 2:
       p[0] = p[1]
     else:
       p[0] = NfaBuilder.or_graphs([p[1], p[3]])
@@ skipping 164 matching lines @@
     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)
     # process default_action
     default_action = parser_state.rules['default']['default_action']
     self.default_action = Action(None, default_action[1]) if default_action else None