polyglot.visit

Class AlphaRenamer

java.lang.Object

polyglot.visit.NodeVisitor

polyglot.visit.AlphaRenamer

All Implemented Interfaces:

java.lang.Cloneable, Copy<NodeVisitor>

public class AlphaRenamer
extends NodeVisitor

The AlphaRenamer runs over the AST and alpha-renames any local variable declarations that it encounters.

Nested Class Summary

Nested classes/interfaces inherited from interface polyglot.util.Copy

Copy.Util

Field Summary

Fields

Modifier and Type	Field and Description
protected boolean	createNewLocalInstances Should we create new local instances? (If not, we will imperatively update the old ones).
protected java.util.Set<java.lang.String>	freshVars
protected java.util.Map<java.lang.String,LocalInstance>	localInstanceMemo Memoization holding LocalInstances for renamed locals
protected NodeFactory	nf
protected boolean	renameCatchFormals Should we also alpha-rename catch formals?
protected java.util.Map<java.lang.String,java.lang.String>	renamingMap
protected java.util.Stack<java.util.Set<java.lang.String>>	setStack

Constructor Summary

Constructors

Constructor and Description
AlphaRenamer(NodeFactory nf) Creates a visitor for alpha-renaming locals.
AlphaRenamer(NodeFactory nf, boolean renameCatchFormals)
AlphaRenamer(NodeFactory nf, boolean renameCatchFormals, boolean createNewLocalInstances)

Method Summary

Methods

Modifier and Type	Method and Description
protected void	addToRenamingMap(java.lang.String name)
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, copy, enter, finish, finish, lang, leave, override, override, toString, visitEdge, visitEdgeNoOverride

Methods inherited from class java.lang.Object

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

Field Detail

nf

protected NodeFactory nf

setStack

protected java.util.Stack<java.util.Set<java.lang.String>> setStack

renamingMap

protected java.util.Map<java.lang.String,java.lang.String> renamingMap

localInstanceMemo

protected java.util.Map<java.lang.String,LocalInstance> localInstanceMemo

Memoization holding LocalInstances for renamed locals

freshVars

protected java.util.Set<java.lang.String> freshVars

renameCatchFormals

protected boolean renameCatchFormals

Should we also alpha-rename catch formals?

createNewLocalInstances

protected boolean createNewLocalInstances

Should we create new local instances? (If not, we will imperatively update the old ones).

Constructor Detail

AlphaRenamer

public AlphaRenamer(NodeFactory nf)

Creates a visitor for alpha-renaming locals.

Parameters:

nf - The node factory to be used when generating new nodes.

AlphaRenamer

public AlphaRenamer(NodeFactory nf,
            boolean renameCatchFormals)

AlphaRenamer

public AlphaRenamer(NodeFactory nf,
            boolean renameCatchFormals,
            boolean createNewLocalInstances)

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.

addToRenamingMap

protected void addToRenamingMap(java.lang.String name)

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 overridden, enter and leave are each called exactly once.

Note that if old == n then the visitor 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.