xxl.cursors
Class Mapper

java.lang.Object
  |
  +--xxl.cursors.Mapper

public class Mapper

extends java.lang.Object

implements Cursor

Tha Mapper maps an input-Object-array to an output-Object with a given Function. The Mapper takes n iterators as its input and takes them as parameters to a given n-ary function. Important: The function of the Mapper is called with an Object-array.

Field Summary

protected boolean	allowPartialInput
protected java.lang.Object[]	arguments
protected Cursor[]	cursors
protected Function	function
protected boolean	supportsPeek

Constructor Summary

Mapper(java.util.Iterator[] iterators)
Creates a new Mapper.

Mapper(java.util.Iterator[] iterators, Function function)
Creates a new Mapper.

Mapper(java.util.Iterator[] iterators, Function function, boolean allowPartialInput)
Creates a new Mapper.

Mapper(java.util.Iterator iterator, Function function)
Creates a new Mapper.

Mapper(java.util.Iterator iterator0, java.util.Iterator iterator1)
Creates a new Mapper.

Mapper(java.util.Iterator iterator0, java.util.Iterator iterator1, Function function)
Creates a new Mapper.

Method Summary

void	close() Closes the Cursor.
boolean	hasNext() Returns true if the iteration has more elements.
java.lang.Object	next() Returns the next element in the iteration.
java.lang.Object	peek() Shows the next element in the iteration without removing it.
void	remove() Removes from the underlying collection the last element returned by the iterator (optional operation).
void	reset() Resets the Cursor to its initial state.
boolean	supportsPeek() Returns true if the peek operation is supported by this PeekIterator.
void	update(java.lang.Object object) Replaces the object that was returned by the last call to next() or peek().

Methods inherited from class java.lang.Object

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

Field Detail

cursors

protected Cursor[] cursors

function

protected Function function

arguments

protected java.lang.Object[] arguments

supportsPeek

protected boolean supportsPeek

allowPartialInput

protected boolean allowPartialInput

Constructor Detail

Mapper

public Mapper(java.util.Iterator[] iterators,
              Function function,
              boolean allowPartialInput)

Creates a new Mapper.

Parameters:

iterators - the input-Iterators

function - the Function used to map elements

allowPartialInput - true iff TODO

Mapper

public Mapper(java.util.Iterator[] iterators,
              Function function)

Creates a new Mapper.

Parameters:

iterators - the input-Iterators

function - the Function used to map elements

Mapper

public Mapper(java.util.Iterator[] iterators)

Creates a new Mapper.

Parameters:

iterators - the input-Iterators

Mapper

public Mapper(java.util.Iterator iterator,
              Function function)

Creates a new Mapper.

Parameters:

iterator - the input-Iterator

function - the Function used to map elements

Mapper

public Mapper(java.util.Iterator iterator0,
              java.util.Iterator iterator1)

Creates a new Mapper.

Parameters:

iterator0 - the first input-Iterator

iterator1 - the second input-Iterator

Mapper

public Mapper(java.util.Iterator iterator0,
              java.util.Iterator iterator1,
              Function function)

Creates a new Mapper.

Parameters:

iterator0 - the first input-Iterator

iterator1 - the second input-Iterator

function - the Function used to map elements

Method Detail

close

public void close()

Closes the Cursor. Signals the cursor to cleanup resources, close files, etc. After a call to close() calls to methods like next() or peek() are not guarantied to yield proper results.

Specified by:

close in interface Cursor

hasNext

public boolean hasNext()

Returns true if the iteration has more elements.

Specified by:

hasNext in interface Cursor

Returns:

true if the iterator has more elements.

next

public java.lang.Object next()
                      throws java.util.NoSuchElementException

Returns the next element in the iteration.

Specified by:

next in interface Cursor

Returns:

the next element in the iteration.

Throws:

java.util.NoSuchElementException - iteration has no more elements.

peek

public java.lang.Object peek()
                      throws java.util.NoSuchElementException,
                             java.lang.UnsupportedOperationException

Shows the next element in the iteration without removing it.

Specified by:

peek in interface Cursor

Returns:

the next element in the iteration.

Throws:

java.util.NoSuchElementException - iteration has no more elements.

java.lang.UnsupportedOperationException - if the peek operation is not supported by this PeekIterator.

remove

public void remove()
            throws java.lang.UnsupportedOperationException

Removes from the underlying collection the last element returned by the iterator (optional operation).

Specified by:

remove in interface Cursor

Throws:

java.lang.IllegalStateException - if the next method has not yet been called, or the remove method has already been called after the last call to the next method.

java.lang.UnsupportedOperationException - if the remove operation is not supported by this PeekIterator.

reset

public void reset()
           throws java.lang.UnsupportedOperationException

Resets the Cursor to its initial state.

Specified by:

reset in interface Cursor

supportsPeek

public boolean supportsPeek()

Returns true if the peek operation is supported by this PeekIterator.

Specified by:

supportsPeek in interface Cursor

Returns:

true if the peek operation is supported by this PeekIterator.

update

public void update(java.lang.Object object)
            throws java.lang.UnsupportedOperationException

Replaces the object that was returned by the last call to next() or peek(). This operation must not be called after a call to hasNext(). It should foow a call to next() or peek().

Specified by:

update in interface Cursor

Parameters:

object - the object that replaces the object returned by the last call to next() or peek()