eworks.RQL.model
Class ProjectionList

java.lang.Object
  eworks.RQL.model.ProjectionList

public class ProjectionList

extends Object

Represents a list of Projection-instances, that is the list of variables that are part of a query's result (other variables may be bound as well, but will not be returned as the query's result). This aspect and terminology is copied from database query languages like SQL.

Version:

1.00 (2003-11-03)

Author:

Fabian Wleklinski (fabian@wleklinski.de)

See Also:

Projection, The RDF Query Language (RQL)

Constructor Summary

ProjectionList()
Creates a new and empty projection list.

ProjectionList(Projection projection)
Creates a new projection list and encapsulates a certain projection.

Method Summary

void	add(Projection projection) Adds a new projection to this projection list.
Projection	get(int i) Returns the i-th projection that is encapsulated by this projection list.
int	getLength() Returns the number of projections encapsulated by this projection list.
String	toString() Returns this projection list's string representation.

Methods inherited from class java.lang.Object

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

Constructor Detail

ProjectionList

public ProjectionList()

Creates a new and empty projection list.

ProjectionList

public ProjectionList(Projection projection)

Creates a new projection list and encapsulates a certain projection.

Parameters:

projection - The projection list's only encapsulated projection.

Method Detail

getLength

public int getLength()

Returns the number of projections encapsulated by this projection list.

Returns:

The number of projections.

get

public Projection get(int i)

Returns the i-th projection that is encapsulated by this projection list.

Parameters:

i - The number of the projection to return.

Returns:

The i-th projection (0 <= i <= getLength()).

Throws:

ArrayIndexOutOfBoundsException - if i is negative or not lower than getLength().

See Also:

getLength()

add

public void add(Projection projection)

Adds a new projection to this projection list.

Parameters:

projection - The projection to add.

toString

public String toString()

Returns this projection list's string representation.

Returns:

This projection list's string representation.