Class ConstantFolder

  extended by polyglot.visit.NodeVisitor
      extended by polyglot.visit.ConstantFolder

public class ConstantFolder
extends NodeVisitor

Visitor which performs constant folding.

Constructor Summary
ConstantFolder(TypeSystem ts, NodeFactory nf)
Method Summary
 Node leave(Node old, Node n, NodeVisitor v_)
          This method is called after all of the children of n have been visited.
 NodeFactory nodeFactory()
 TypeSystem typeSystem()
Methods inherited from class polyglot.visit.NodeVisitor
begin, enter, 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


public ConstantFolder(TypeSystem ts,
                      NodeFactory nf)
Method Detail


public TypeSystem typeSystem()


public NodeFactory nodeFactory()


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.

leave in class NodeVisitor
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.
The final result of the traversal of the tree rooted at n.