polyglot.visit
Class NodeScrambler.FirstPass

java.lang.Object
  polyglot.visit.NodeVisitor
      polyglot.visit.NodeScrambler.FirstPass

Enclosing class:

NodeScrambler

public class NodeScrambler.FirstPass
extends NodeVisitor

Scans throught the AST, create a list of all nodes present, along with the set of parents for each node in the tree. This visitor should be run before the main NodeScrambler visits the tree.

Constructor Summary

NodeScrambler.FirstPass()

Method Summary

NodeVisitor	enter(Node n) Begin normal traversal of a subtree rooted at n.
Node	leave(Node old, Node n, NodeVisitor v) This method is called after all of the children of n have been visited.

Methods inherited from class polyglot.visit.NodeVisitor

begin, enter, finish, finish, leave, override, override, toString, visitEdge

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

NodeScrambler.FirstPass

public NodeScrambler.FirstPass()

Method Detail

enter

public NodeVisitor enter(Node n)

Description copied from class: NodeVisitor

Begin normal traversal of a subtree rooted at n. This gives the visitor the option of changing internal state or returning a new visitor which will be used to visit the children of n.

This method is typically called by the method enter(parent, n). If a subclass overrides the method enter(parent, n) then this method may not be called.

Overrides:

enter in class NodeVisitor

Parameters:

n - The root of the subtree to be traversed.

Returns:

The NodeVisitor which should be used to visit the children of n.

leave

public Node leave(Node old,
                  Node n,
                  NodeVisitor v)

Description copied from class: NodeVisitor

This method is called after all of the children of n have been visited. In this case, these children were visited by the visitor v. This is the last chance for the visitor to modify the tree rooted at n. This method will be called exactly the same number of times as entry is called. That is, for each node that is not overriden, enter and leave are each called exactly once.

Note that if old == n then the vistior should make a copy of n before modifying it. It should then return the modified copy.

This method is typically called by the method leave(parent, old, n v). If a subclass overrides the method leave(parent, old, n v) then this method may not be called.

Overrides:

leave in class NodeVisitor

Parameters:

old - The original state of root of the current subtree.

n - The current state of the root of the current subtree.

v - The NodeVisitor object used to visit the children.

Returns:

The final result of the traversal of the tree rooted at n.