cetus.hir

Class DFIterator<E extends Traversable>

java.lang.Object

cetus.hir.IRIterator<E>

cetus.hir.DFIterator<E>

All Implemented Interfaces:

java.util.Iterator<E>

public class DFIterator<E extends Traversable>
extends IRIterator<E>

Alternative implementation to DepthFirstIterator, which supports depth-first iteration over a specific type when requested. Unlike DepthFirstIterator, DFIterator does not allocate internal storage to place next items to be searched for; it performs memory-less search by visiting the node in the IR tree to find the next item to be returned.

Constructor Summary

Constructors

Constructor and Description
DFIterator(Traversable root) Constructs a new iterator that returns any traversable nodes during iteration.
DFIterator(Traversable root, java.lang.Class<? extends Traversable> c) Constructs a new iterator that returns the specified IR type during iteration.

Method Summary

Methods

Modifier and Type	Method and Description
java.util.List<E>	getList() Returns a list of traversed elements of type E using the current iterator.
boolean	hasNext() Checks if there is a next element of the requested type.
E	next() Returns the next IR node.
void	pruneOn(java.lang.Class<? extends Traversable> c) Considers the specified IR class type as one whose child nodes are not visited during iteration.
void	reset() Initializes the iterator by placing the first item to be returned for a call to next().
void	setNext(E next) Forces the specified traversable element next to be returned when next() is called.

Methods inherited from class cetus.hir.IRIterator

next, next, nextExcept, remove

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

DFIterator

public DFIterator(Traversable root)

Constructs a new iterator that returns any traversable nodes during iteration.

Parameters:

root - the initial node for the iteration.

DFIterator

public DFIterator(Traversable root,
          java.lang.Class<? extends Traversable> c)

Constructs a new iterator that returns the specified IR type during iteration.

Parameters:

root - the initial node for the iteration.

c - the IR class type to be iterated over.

Method Detail

hasNext

public boolean hasNext()

Checks if there is a next element of the requested type.

Specified by:

hasNext in interface java.util.Iterator<E extends Traversable>

Specified by:

hasNext in class IRIterator<E extends Traversable>

Returns:

true if there exist a next element of the requested type.

next

public E next()

Returns the next IR node.

Specified by:

next in interface java.util.Iterator<E extends Traversable>

Specified by:

next in class IRIterator<E extends Traversable>

Returns:

the next IR node.

Throws:

java.util.NoSuchElementException - no more elements found.

pruneOn

public void pruneOn(java.lang.Class<? extends Traversable> c)

Considers the specified IR class type as one whose child nodes are not visited during iteration. This method is useful for reducing the cost of iteration.

Parameters:

c - the IR node type to be pruned on.

reset

public void reset()

Initializes the iterator by placing the first item to be returned for a call to next().

Specified by:

reset in class IRIterator<E extends Traversable>

getList

public java.util.List<E> getList()

Returns a list of traversed elements of type E using the current iterator.

Returns:

the collected list.

setNext

public void setNext(E next)

Forces the specified traversable element next to be returned when next() is called. Appropriate use of this method enables IR traversal with modification in a well-defined manner. (experimental)

Parameters:

next - the next traversable element to be returned.