/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.commons.math3.linear;
/**
* This interface defines a visitor for the entries of a vector. Visitors
* implementing this interface do not alter the entries of the vector being
* visited.
*
* @since 3.1
*/
public interface RealVectorPreservingVisitor {
/**
* Start visiting a vector. This method is called once, before any entry
* of the vector is visited.
*
* @param dimension the size of the vector
* @param start the index of the first entry to be visited
* @param end the index of the last entry to be visited (inclusive)
*/
void start(int dimension, int start, int end);
/**
* Visit one entry of the vector.
*
* @param index the index of the entry being visited
* @param value the value of the entry being visited
*/
void visit(int index, double value);
/**
* End visiting a vector. This method is called once, after all entries of
* the vector have been visited.
*
* @return the value returned by
* {@link RealVector#walkInDefaultOrder(RealVectorPreservingVisitor)},
* {@link RealVector#walkInDefaultOrder(RealVectorPreservingVisitor, int, int)},
* {@link RealVector#walkInOptimizedOrder(RealVectorPreservingVisitor)}
* or
* {@link RealVector#walkInOptimizedOrder(RealVectorPreservingVisitor, int, int)}
*/
double end();
}