/*
 *  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 groovy.lang;

import java.util.List;

/**
 * A Range represents the list of all items obtained by starting from a
 * <code>from</code> value and calling <code>next()</code> successively
 * until you reach the <code>to</code> value. For a reverse range,
 * the list is obtained by starting at the <code>to</code> value and
 * successively calling <code>previous()</code> until the <code>from</code>
 * value is reached.
 */
public interface Range<T extends Comparable> extends List<T> {
    /**
     * The lower value in the range.
     *
     * @return the lower value in the range.
     */
    T getFrom();

    /**
     * The upper value in the range.
     *
     * @return the upper value in the range
     */
    T getTo();

    /**
     * Indicates whether this is a reverse range which iterates backwards
     * starting from the to value and ending on the from value
     *
     * @return <code>true</code> if this is a reverse range
     */
    boolean isReverse();

    /**
     * Indicates whether an object is greater than or equal to the <code>from</code>
     * value for the range and less than or equal to the <code>to</code> value.
     * <p>
     * This may be true even for values not contained in the range.
     * <p>
     * Example:   from = 1.5 , to = 3, next() increments by 1
     * containsWithinBounds(2) == true
     * contains(2) == false
     *
     * @param o the object to check against the boundaries of the range
     * @return <code>true</code> if the object is between the from and to values
     */
    boolean containsWithinBounds(Object o);

    /**
     * Steps through the range, calling a closure for each number.
     *
     * @param step    the amount by which to step. If negative, steps through the
     *                range backwards.
     * @param closure the {@link Closure} to call
     */
    void step(int step, Closure closure);

    /**
     * Forms a list by stepping through the range by the indicated interval.
     *
     * @param step the amount by which to step. If negative, steps through the
     *             range backwards.
     * @return the list formed by stepping through the range by the indicated interval.
     */
    List<T> step(int step);

    /**
     * @return the verbose {@link String} representation of this {@link Range} as would be typed into a console to create the {@link Range} instance
     */
    String inspect();
}
