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ASTVisitorc B s8 e Z d Z d Z d � Z d � Z d � Z d � Z RS( s Performs a depth-first walk of the AST
The ASTVisitor will walk the AST, performing either a preorder or
postorder traversal depending on which method is called.
methods:
preorder(tree, visitor)
postorder(tree, visitor)
tree: an instance of ast.Node
visitor: an instance with visitXXX methods
The ASTVisitor is responsible for walking over the tree in the
correct order. For each node, it checks the visitor argument for
a method named 'visitNodeType' where NodeType is the name of the
node's class, e.g. Class. If the method exists, it is called
with the node as its sole argument.
The visitor method for a particular node type can control how
child nodes are visited during a preorder walk. (It can't control
the order during a postorder walk, because it is called _after_
the walk has occurred.) The ASTVisitor modifies the visitor
argument by adding a visit method to the visitor; this method can
be used to visit a child node of arbitrary type.
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getChildNodest dispatch( R R t argst child( ( s( /usr/lib64/python2.7/compiler/visitor.pyt default& s c G su | | _ | j } | j j | d � } | d k rh | j } t | j d | | j � } | | j | <n | | | � S( Nt visit( R t __class__R t getR t __name__t getattrt visitorR ( R R R t klasst metht className( ( s( /usr/lib64/python2.7/compiler/visitor.pyR * s c G s) | | _ | j | _ | j | | � d S( s& Do preorder walk of tree using visitorN( R R R ( R t treeR R ( ( s( /usr/lib64/python2.7/compiler/visitor.pyt preorder; s ( R t
__module__t __doc__t VERBOSER R R R ( ( ( s( /usr/lib64/python2.7/compiler/visitor.pyR s t ExampleASTVisitorc B s e Z d Z i Z d � Z RS( s� Prints examples of the nodes that aren't visited
This visitor-driver is only useful for development, when it's
helpful to develop a visitor incrementally, and get feedback on what
you still have to do.
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