Package org.eclipse.equinox.p2.query

Class ExpressionQuery<T>

java.lang.Object

org.eclipse.equinox.p2.query.ExpressionQuery<T>

All Implemented Interfaces:

IQueryWithIndex<T>, IQuery<T>

public class ExpressionQuery<T>
extends Object
implements IQueryWithIndex<T>

A query that evaluates using an iterator as input and produces a new iterator.

Since:

2.0

Constructor Summary

Constructors

Constructor	Description
ExpressionQuery(Class<? extends T> matchingClass, String expression, Object... parameters)
ExpressionQuery(Class<? extends T> elementClass, IExpression expression, Object... parameters)

Method Summary

Modifier and Type	Method	Description
static <T> IContextExpression<T>	createExpression(IQuery<T> query)
Class<? extends T>	getElementClass()
static <T> Class<? extends T>	getElementClass(IQuery<T> query)
IContextExpression<T>	getExpression()	Returns the IExpression backing this query or null if this is not an expression query.
IQueryResult<T>	perform(Iterator<T> iterator)	Evaluates the query for a specific input.
IQueryResult<T>	perform(IIndexProvider<T> indexProvider)	Evaluates the query using the indexProvider.

Methods inherited from class java.lang.Object

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

Constructor Details

ExpressionQuery

public ExpressionQuery(Class<? extends T> elementClass,
 IExpression expression,
 Object... parameters)

ExpressionQuery

public ExpressionQuery(Class<? extends T> matchingClass,
 String expression,
 Object... parameters)

Method Details

getElementClass

public Class<? extends T> getElementClass()

perform

public IQueryResult<T> perform(IIndexProvider<T> indexProvider)

Description copied from interface: IQueryWithIndex

Evaluates the query using the indexProvider. The query is first analyzed for index candidates (typically expressions like id == <some value>) and if possible, indexes returned by IIndexProvider.getIndex(String) will be used in place of the iterator returned by IIndexProvider.everything().

Specified by:

perform in interface IQueryWithIndex<T>

Parameters:

indexProvider - The provider of the material to evaluate the query on

Returns:

The results of the query.

perform

public IQueryResult<T> perform(Iterator<T> iterator)

Description copied from interface: IQuery

Evaluates the query for a specific input.

Specified by:

perform in interface IQuery<T>

Parameters:

iterator - The elements for which to evaluate the query on

Returns:

The results of the query.

getExpression

public IContextExpression<T> getExpression()

Description copied from interface: IQuery

Returns the IExpression backing this query or null if this is not an expression query.

Specified by:

getExpression in interface IQuery<T>

Returns:

An expression or null.

getElementClass

public static <T> Class<? extends T> getElementClass(IQuery<T> query)

createExpression

public static <T> IContextExpression<T> createExpression(IQuery<T> query)