Experimental parser: visualize rule trees.

tools/lexer_generator/rule_parser.py

Index: tools/lexer_generator/rule_parser.py
diff --git a/tools/lexer_generator/rule_parser.py b/tools/lexer_generator/rule_parser.py
index 65b3f17a158fe9601a9c4e52ac4ad8e8cc92f779..fb823ca088511a38e896ed036f4314d533de57f5 100644
--- a/tools/lexer_generator/rule_parser.py
+++ b/tools/lexer_generator/rule_parser.py
@@ -246,6 +246,7 @@ class RuleProcessor(object):
 
   def __init__(self, parser_state):
     self.__automata = {}
+    self.__rule_trees = {}
     self.__process_parser_state(parser_state)
 
   @staticmethod
@@ -260,6 +261,12 @@ class RuleProcessor(object):
   def default_automata(self):
     return self.__automata['default']
 
+  def rule_tree_dots(self):
+    result = {}
+    for rule in self.__rule_trees:
+      result[rule] = NfaBuilder.rule_tree_dot(self.__rule_trees[rule])
+    return result
+
   class Automata(object):
 
     def __init__(self, builder, graph):
@@ -328,6 +335,7 @@ class RuleProcessor(object):
     # 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