org.eclipse.ocl.Query Maven / Gradle / Ivy
/**
*
*
* Copyright (c) 2005, 2007 IBM Corporation and others.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* IBM - Initial API and implementation
*
*
*
* $Id: Query.java,v 1.1 2007/01/25 18:24:37 cdamus Exp $
*/
package org.eclipse.ocl;
import java.util.List;
import java.util.Map;
import java.util.Set;
import org.eclipse.emf.ecore.EObject;
import org.eclipse.ocl.expressions.OCLExpression;
import org.eclipse.ocl.types.OCLStandardLibrary;
/**
* An OCL constraint or query. The query is validated for correctness
* when it is created. The query can subsequently be evaluated on a single
* object or on multiple objects in one operation.
*
* See the {@link Environment} class for a description of the
* generic type parameters of this class.
*
*
* @author Edith Schonberg (edith)
* @author Christian W. Damus (cdamus)
*/
public interface Query {
/**
* Obtains the evaluation environment that I use to evaluate OCL expressions.
*
* @return my environment
*/
EvaluationEnvironment getEvaluationEnvironment();
/**
* Evaluates the query on the object.
*
* @param obj an Object
*
* @return the result of the query, which may be one or more
* {@link EObject}s, Java objects, a mixture, or even null.
* In any case, the results conform to the expression's
* {@linkplain #resultType() result type}
*
* @see #evaluate()
* @see #evaluate(List)
* @see #resultType()
*/
public Object evaluate(Object obj);
/**
* Evaluates the query. This method is used when there is no 'self' context
* required by the query.
* Either the query is constant, or uses allInstances()
* exclusively for evaluation.
*
* @return the result of the query, which may be one or more
* {@link EObject}s, Java objects, a mixture, or even null.
* In any case, the results conform to the expression's
* {@linkplain #resultType() result type}
*
* @see #resultType()
*/
public Object evaluate();
/**
* Evaluates the query on an object. The query must be a boolean valued
* constraint.
*
* @param obj an Object or null if the query
* does not require an OCL 'self' context
* @return boolean true or false according to
* whether the constraint is met
*
* @see #check(List)
*/
public boolean check(Object obj);
/**
* Evaluates the query on the input list.
* The results are returned in a corresponding list of results.
*
* @param objects a list of objects to evaluate the query on
* @return a list of results, corresponding one-for-one with the
* objects. Note that result elements may, themselves,
* be collections of multiple results for a single input object.
* In any case, the results conform to the expression's
* {@linkplain #resultType() result type}
*
* @see #evaluate(Object)
* @see #resultType()
*/
public List evaluate(List objects);
/**
* Determines whether all of the input objects satisfy the query.
* The query must be a boolean-valued constraint.
*
* @param objects a list of objects to evaluate the constraint on
* @return true if all of the objects satisfy
* the constraint (including the trivial case of an empty input list);
* false, otherwise
*
* @see #check(Object)
*/
public boolean check(List objects);
/**
* Determines the subset of input objects that satisfy the query.
* The query must be a boolean valued constraint.
*
* @param objects a list of objects to evaluate the constraint on
* @return the subset (possibly empty) of the objects that
* satisfy the constraint
*/
public List select(List objects);
/**
* Determines the subset of input objects that do not satisfy the
* query. The query must be a boolean valued constraint.
*
* @param objects a list of objects to evaluate the constraint on
* @return the subset (possibly empty) of the objects that
* do not satisfy the constraint
*/
public List reject(List objects);
/**
* Obtains the OCL result type of the query. This may be a classifier
* in the user model, or it may represent a pre-defined OCL data type
* such as {@link OCLStandardLibrary#getBoolean() Boolean}.
*
* @return the query's result type
*/
public C resultType();
/**
* Translates the query back to an OCL text string.
*
* @return the text of the OCL query expression
*/
public String queryText();
/**
* Obtains the mapping of classes to their extents (sets of all instances).
*
* @return the map of classes to their extents
*
* @see OCL#setExtentMap
*/
public Map> getExtentMap();
/**
* Obtains the expression that I evaluate (or check as a boolean constraint).
*
* @return my OCL expression
*/
OCLExpression getExpression();
}