10   def __init__(self, tgt):  argument
11     self.tgt = tgt
12     self.pos = ""
13     self.prereqs = set()
14     self.visit = 0
16   def add(self, prereq):  argument
17     self.prereqs.add(prereq)
21   def __init__(self):  argument
22     self.lines = {}
23     self.__visit = 0
24     self.count = 0
26   def add(self, tgt, prereq):  argument
27     t = self.lines.get(tgt)
30       self.lines[tgt] = t
31     p = self.lines.get(prereq)
34       self.lines[prereq] = p
36     self.count = self.count + 1
38   def setPos(self, tgt, pos):  argument
39     t = self.lines.get(tgt)
42       self.lines[tgt] = t
45   def get(self, tgt):  argument
46     if self.lines.has_key(tgt):
47       return self.lines[tgt]
51   def __iter__(self):  argument
52     return self.lines.iteritems()
54   def trace(self, tgt, prereq):  argument
55     self.__visit = self.__visit + 1
56     d = self.lines.get(tgt)
59     return self.__trace(d, prereq)
61   def __trace(self, d, prereq):  argument
62     if d.visit == self.__visit:
66     d.visit = self.__visit
69       recursed = self.__trace(pre, prereq)