Experimental parser: some unit tests

tools/lexer_generator/dfa.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 60 matching lines @@
     visited = set()
     while edge:
       f = lambda (next_edge, state), node: (
         next_edge | set(node.transitions().values()),
         visitor(node, state))
       (next_edge, state) = reduce(f, edge, (set(), state))
       visited |= edge
       edge = next_edge - visited
     return state
 
+  def matches(self, string):
+    state = self.__start
+    for c in string:
+      next_state = None
+      for key, transition_state in state.transitions().items():
+        if key.matches_char(c):
+          next_state = transition_state
+          break
+      if not next_state:
+        return False
+      state = next_state
+    return state in self.__terminal_set
+
   def to_dot(self):
 
     def f(node, node_content):
       for key, value in node.transitions().items():
         node_content.append(
           "  S_%s -> S_%s [ label = \"%s\" ];" %
             (node.node_number(), value.node_number(), key))
       return node_content
 
     node_content = self.__visit_edges(self.__start, f, [])
     terminals = ["S_%d;" % x.node_number() for x in self.__terminal_set]
     start_number = self.__start.node_number()
     start_shape = "circle"
     if self.__start in self.__terminal_set:
       start_shape = "doublecircle"
 
     return '''
 digraph finite_state_machine {
   rankdir=LR;
   node [shape = %s, style=filled, bgcolor=lightgrey]; S_%s
   node [shape = doublecircle, style=unfilled]; %s
   node [shape = circle];
 %s
 }
     ''' % (start_shape,
            start_number,
            " ".join(terminals),
            "\n".join(node_content))