Experimental parser: cleanup rule processing result

tools/lexer_generator/dfa.py

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 from automaton import *
-from nfa import Nfa
 from transition_keys import TransitionKey
 
 class DfaState(AutomatonState):
 
   def __init__(self, name, action):
     super(DfaState, self).__init__()
     self.__name = name
     self.__transitions = {}
     self.__action = action
 
@@ skipping 11 matching lines @@
     self.__transitions[key] = state
 
   def transitions(self):
     return self.__transitions
 
 class Dfa(Automaton):
 
   def __init__(self, start_name, mapping):
     super(Dfa, self).__init__()
     self.__terminal_set = set()
-    self.__name_map = {}
+    name_map = {}
     for name, node_data in mapping.items():
       node = DfaState(name, node_data['action'])
-      self.__name_map[name] = node
+      name_map[name] = node
       if node_data['terminal']:
         self.__terminal_set.add(node)
     for name, node_data in mapping.items():
-      node = self.__name_map[name]
+      node = name_map[name]
       inversion = {}
       for key, state in node_data['transitions'].items():
         if not state in inversion:
           inversion[state] = []
         inversion[state].append(key)
       for state, keys in inversion.items():
         merged_key = TransitionKey.merged_key(keys)
-        node.add_transition(merged_key, self.__name_map[state])
-    self.__start = self.__name_map[start_name]
+        node.add_transition(merged_key, name_map[state])
+    self.__start = name_map[start_name]
+    self.__node_count = len(mapping)
+    self.__verify()
+
+  def __verify(self):
     assert self.__terminal_set
+    state_count = self.visit_all_states(lambda state, count: count + 1, 0)
+    assert self.__node_count == state_count
 
   def start_state(self):
     return self.__start
 
   def start_set(self):
     return set([self.__start])
 
   def terminal_set(self):
     return set(self.__terminal_set)
 
   def all_states_iter(self):
-    return iter(self.__name_map.values())
+    return self.__start.state_iter()
 
   @staticmethod
   def __match_char(state, char):
     match = list(state.state_iter(key_filter = lambda k: k.matches_char(char)))
     if not match: return None
     assert len(match) == 1
     return match[0]
 
   def collect_actions(self, string):
     state = self.__start
@@ skipping 24 matching lines @@
         last_position = pos
         # lex next token
         next = Dfa.__match_char(self.__start, c)
         assert next
       state = next
     assert state.action() # must invoke default action here
     yield (state.action(), last_position, len(string))
 
   def minimize(self):
     pass