mwalk.visitor
Class GlobalVisitor

java.lang.Object
  |
  +--mwalk.visitor.AbstractVisitor
        |
        +--mwalk.visitor.GlobalVisitor

Direct Known Subclasses:

RandomVisitor

public class GlobalVisitor

extends AbstractVisitor

implements UpVisitor, DownVisitor

A compund visitor which runs a pair of visitors, one walking up the tree and a second which walks back down.

Version:

1.0

Author:

Robert Chalmers

Field Summary

private static java.lang.String	CFG_BASE Base of keys in configuration file
protected DownVisitor	dv Visitor to use while walking down the tree
protected boolean	goingUp Flag indicating whether we are currently walking up the tree
protected long	round Current round
protected long	rounds Number of rounds and current repitition
protected UpVisitor	uv Visitor to use while walking up the tree

Fields inherited from class mwalk.visitor.AbstractVisitor

CFG_BASE, eval, seen, verbose

Constructor Summary

GlobalVisitor()
Default constructor.

GlobalVisitor(DownVisitor dv)

GlobalVisitor(DownVisitor dv, int rounds)

GlobalVisitor(int rounds)

GlobalVisitor(UpVisitor uv, DownVisitor dv)

GlobalVisitor(UpVisitor uv, DownVisitor dv, int rounds)

Method Summary

boolean	again(Tree tree) Check whether the visitor wants another pass over the tree.
TreeNode[]	getChildren(Tree tree, TreeNode node) Get a list of children for the current node applying correct activity semantics.
TreeNode[]	getParents(Tree tree, TreeNode node) Get a list of parents for the current node applying correct activity semantics.
java.util.Enumeration	getReceivers(Tree tree) Get a list of active receivers.
boolean	init(Tree tree) Initialize the visitor state.
boolean	nextReceiver(Tree tree, Receiver recv) Check whether the next receiver should start a visiting path.
boolean	postfix() Whether to visit after visiting parent/children.
boolean	prefix() Whether to visit prior to visiting parent/children.
void	prepare(Tree tree) Prepare the up/down visitors for a new pass over the tree.
void	reset(Tree tree) Reset the visitor for a new pass over the tree.
java.lang.Object	visitDown(Tree tree, TreeNode node) Visit the current node prior to visiting children.
java.lang.Object	visitDown(Tree tree, TreeNode node, java.util.Vector list) Visit the current node after visiting children.
java.lang.Object	visitUp(Tree tree, TreeNode node) Visit the current node prior to visiting parent.
java.lang.Object	visitUp(Tree tree, TreeNode node, java.util.Vector list) Visit the current node after visiting parent.
boolean	walkDown() Whether to walk down the tree.
boolean	walkUp() Whether to walk up the tree.

Methods inherited from class mwalk.visitor.AbstractVisitor

cfgBoolean, cfgInt, cfgString, cfgVisitor, evaluator, evaluator, haveSeen, haveVisited, markSeen, markVisited, verbose

Methods inherited from class java.lang.Object

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

Field Detail

CFG_BASE

private static final java.lang.String CFG_BASE

Base of keys in configuration file

uv

protected UpVisitor uv

Visitor to use while walking up the tree

dv

protected DownVisitor dv

Visitor to use while walking down the tree

goingUp

protected boolean goingUp

Flag indicating whether we are currently walking up the tree

rounds

protected long rounds

Number of rounds and current repitition

round

protected long round

Current round

Constructor Detail

GlobalVisitor

public GlobalVisitor()

Default constructor.

GlobalVisitor

public GlobalVisitor(int rounds)

GlobalVisitor

public GlobalVisitor(DownVisitor dv)

GlobalVisitor

public GlobalVisitor(UpVisitor uv,
                     DownVisitor dv)

GlobalVisitor

public GlobalVisitor(DownVisitor dv,
                     int rounds)

GlobalVisitor

public GlobalVisitor(UpVisitor uv,
                     DownVisitor dv,
                     int rounds)

Method Detail

prefix

public boolean prefix()

Whether to visit prior to visiting parent/children.

Overrides:

prefix in class AbstractVisitor

Returns:

boolean whether to visit prior

postfix

public boolean postfix()

Whether to visit after visiting parent/children.

Overrides:

postfix in class AbstractVisitor

Returns:

boolean whether to visit after

walkUp

public boolean walkUp()

Whether to walk up the tree.

Specified by:

walkUp in interface UpVisitor

Overrides:

walkUp in class AbstractVisitor

Returns:

boolean whether to walk up the tree

walkDown

public boolean walkDown()

Whether to walk down the tree.

Specified by:

walkDown in interface DownVisitor

Overrides:

walkDown in class AbstractVisitor

Returns:

boolean whether to walk down the tree

init

public boolean init(Tree tree)

Initialize the visitor state.

Overrides:

init in class AbstractVisitor

Parameters:

Tree - current tree instance

reset

public void reset(Tree tree)

Reset the visitor for a new pass over the tree.

Overrides:

reset in class AbstractVisitor

Parameters:

Tree - vistited tree

again

public boolean again(Tree tree)

Check whether the visitor wants another pass over the tree. Repeat complete up/down series for total number of rounds.

Overrides:

again in class AbstractVisitor

Parameters:

Tree - vistited tree

Returns:

boolean whether to walk again

prepare

public void prepare(Tree tree)

Prepare the up/down visitors for a new pass over the tree.

Parameters:

Tree - vistited tree

nextReceiver

public boolean nextReceiver(Tree tree,
                            Receiver recv)

Check whether the next receiver should start a visiting path.

Specified by:

nextReceiver in interface UpVisitor

Overrides:

nextReceiver in class AbstractVisitor

Parameters:

Tree - current tree instance

Receiver - next receiver

Returns:

boolean whether to visit next receiver

getReceivers

public java.util.Enumeration getReceivers(Tree tree)

Get a list of active receivers.

Specified by:

getReceivers in interface UpVisitor

Overrides:

getReceivers in class AbstractVisitor

Parameters:

Tree - current tree instance

Returns:

Enumeration list of receivers to visit

visitUp

public java.lang.Object visitUp(Tree tree,
                                TreeNode node)
                         throws VisitException

Visit the current node prior to visiting parent.

Specified by:

visitUp in interface UpVisitor

Overrides:

visitUp in class AbstractVisitor

Parameters:

Tree - current tree instance

TreeNode - current node

Returns:

Object optional return value to pass back along the path

Throws:

VisitException - if a problem ocurred during visit

visitUp

public java.lang.Object visitUp(Tree tree,
                                TreeNode node,
                                java.util.Vector list)
                         throws VisitException

Visit the current node after visiting parent.

Specified by:

visitUp in interface UpVisitor

Overrides:

visitUp in class AbstractVisitor

Parameters:

Tree - current tree instance

TreeNode - current node

Object - list of return values passed back along the path

Returns:

Object optional return value to pass back along the path

Throws:

VisitException - if a problem ocurred during visit

visitDown

public java.lang.Object visitDown(Tree tree,
                                  TreeNode node)
                           throws VisitException

Visit the current node prior to visiting children. This method is called if prefix() returns true.

Specified by:

visitDown in interface DownVisitor

Overrides:

visitDown in class AbstractVisitor

Parameters:

Tree - current tree instance

TreeNode - current node

Returns:

Object optional return value to pass back along the path

Throws:

VisitException - if a problem ocurred during visit

visitDown

public java.lang.Object visitDown(Tree tree,
                                  TreeNode node,
                                  java.util.Vector list)
                           throws VisitException

Visit the current node after visiting children. This method is called if postfix() returns true.

Specified by:

visitDown in interface DownVisitor

Overrides:

visitDown in class AbstractVisitor

Parameters:

Tree - current tree instance

TreeNode - current node

Object - list of return values passed back along the path

Returns:

Object optional return value to pass back along the path

Throws:

VisitException - if a problem ocurred during visit

getParents

public TreeNode[] getParents(Tree tree,
                             TreeNode node)

Get a list of parents for the current node applying correct activity semantics.

Specified by:

getParents in interface UpVisitor

Overrides:

getParents in class AbstractVisitor

Parameters:

Tree - current tree instance

TreeNode - current node

Returns:

TreeNode[] array of active parent nodes

getChildren

public TreeNode[] getChildren(Tree tree,
                              TreeNode node)

Get a list of children for the current node applying correct activity semantics.

Specified by:

getChildren in interface DownVisitor

Overrides:

getChildren in class AbstractVisitor

Parameters:

Tree - current tree instance

TreeNode - current node

Returns:

TreeNode[] list of active children nodes