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163
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1 from .astnodes import *
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2
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3 class Visitor:
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215
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4 """
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5 Visitor that can visit all nodes in the AST
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6 and run pre and post functions.
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7 """
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8 def visit(self, node, f_pre=None, f_post=None):
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9 self.f_pre = f_pre
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10 self.f_post = f_post
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11 self.do(node)
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12
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13 def do(self, node):
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163
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14 # Run visitor:
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215
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15 if self.f_pre:
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16 self.f_pre(node)
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17
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163
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18 # Descent into subnodes:
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19 if type(node) is Package:
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215
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20 for decl in node.declarations:
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21 self.do(decl)
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163
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22 elif type(node) is Function:
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215
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23 for s in node.declarations:
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24 self.do(s)
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25 self.do(node.body)
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163
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26 elif type(node) is CompoundStatement:
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27 for s in node.statements:
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215
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28 self.do(s)
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163
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29 elif type(node) is IfStatement:
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215
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30 self.do(node.condition)
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31 self.do(node.truestatement)
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32 self.do(node.falsestatement)
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167
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33 elif type(node) is FunctionCall:
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34 for arg in node.args:
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215
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35 self.do(arg)
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163
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36 elif type(node) is Assignment:
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215
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37 self.do(node.lval)
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38 self.do(node.rval)
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163
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39 elif type(node) is ReturnStatement:
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215
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40 self.do(node.expr)
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163
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41 elif type(node) is Binop:
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215
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42 self.do(node.a)
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43 self.do(node.b)
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166
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44 elif type(node) is Constant:
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215
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45 self.do(node.value)
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166
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46 elif type(node) in [EmptyStatement, VariableUse, Variable, Literal, FunctionType]:
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163
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47 # Those nodes do not have child nodes.
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48 pass
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176
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49 elif type(node) is WhileStatement:
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215
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50 self.do(node.condition)
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51 self.do(node.statement)
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163
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52 else:
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215
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53 raise Exception('Could not visit "{0}"'.format(node))
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163
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54
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215
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55 # run post function
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56 if self.f_post:
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57 self.f_post(node)
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58
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