Experimental lexer generator: fix actions in graphs.

tools/lexer_generator/automaton.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 49 matching lines @@
   def generate_dot(start_node, terminal_set, edge_iterator, state_iterator):
 
     def escape(v):
       v = str(v).replace('\r', '\\\\r')
       v = str(v).replace('\t', '\\\\t')
       v = str(v).replace('\n', '\\\\n')
       v = str(v).replace('\\', '\\\\')
       v = str(v).replace('\"', '\\\"')
       return v
 
-    def f(node, node_content):
+    def f(node, content):
+      (node_content, edge_content) = content
+      if node.action():
+        action_text = node.action()[1].split('\n')[0]
+        node_content.append('  S_l%s[shape = box, label="%s"];' %
+                            (node.node_number(), action_text))
+        node_content.append('  S_%s -> S_l%s [arrowhead = none];' %
+                            (node.node_number(), node.node_number()))
       for key, values in node.transitions().items():
         if key == TransitionKey.epsilon():
           key = "ε"
         for state in state_iterator(values):
-          action = state.action()
-          if action:
-            content = "  S_%s -> S_%s [ label = \"%s {%s}:%d\" ];" % (
-                node.node_number(),
-                state.node_number(),
-                escape(key),
-                escape(action[1]),
-                action[0])
-          else:
-            content = "  S_%s -> S_%s [ label = \"%s\" ];" % (
-                node.node_number(), state.node_number(), escape(key))
-          node_content.append(content)
-      return node_content
+          edge_content.append("  S_%s -> S_%s [ label = \"%s\" ];" % (
+              node.node_number(), state.node_number(), escape(key)))
+      return (node_content, edge_content)
 
-    node_content = edge_iterator(f, [])
     terminals = ["S_%d;" % x.node_number() for x in terminal_set]
+    (node_content, edge_content) = edge_iterator(f, ([], []))
     start_number = start_node.node_number()
     start_shape = "circle"
     if start_node in 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
+%s
 }
     ''' % (start_shape,
            start_number,
            " ".join(terminals),
+           "\n".join(edge_content),
            "\n".join(node_content))