001/*
002 *  Copyright 2001-2005 Stephen Colebourne
003 *
004 *  Licensed under the Apache License, Version 2.0 (the "License");
005 *  you may not use this file except in compliance with the License.
006 *  You may obtain a copy of the License at
007 *
008 *      http://www.apache.org/licenses/LICENSE-2.0
009 *
010 *  Unless required by applicable law or agreed to in writing, software
011 *  distributed under the License is distributed on an "AS IS" BASIS,
012 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 *  See the License for the specific language governing permissions and
014 *  limitations under the License.
015 */
016package org.joda.time.format;
017
018/**
019 * Internal interface for parsing textual representations of datetimes.
020 * <p>
021 * Application users will rarely use this class directly. Instead, you
022 * will use one of the factory classes to create a {@link DateTimeFormatter}.
023 * <p>
024 * The factory classes are:<br />
025 * - {@link DateTimeFormatterBuilder}<br />
026 * - {@link DateTimeFormat}<br />
027 * - {@link ISODateTimeFormat}<br />
028 *
029 * @author Brian S O'Neill
030 * @see DateTimeFormatter
031 * @see DateTimeFormatterBuilder
032 * @see DateTimeFormat
033 * @since 1.0
034 */
035public interface DateTimeParser {
036
037    /**
038     * Returns the expected maximum number of characters consumed.
039     * The actual amount should rarely exceed this estimate.
040     * 
041     * @return the estimated length
042     */
043    int estimateParsedLength();
044
045    /**
046     * Parse an element from the given text, saving any fields into the given
047     * DateTimeParserBucket. If the parse succeeds, the return value is the new
048     * text position. Note that the parse may succeed without fully reading the
049     * text.
050     * <p>
051     * If it fails, the return value is negative. To determine the position
052     * where the parse failed, apply the one's complement operator (~) on the
053     * return value.
054     *
055     * @param bucket  field are saved into this, not null
056     * @param text  the text to parse, not null
057     * @param position  position to start parsing from
058     * @return new position, negative value means parse failed -
059     *  apply complement operator (~) to get position of failure
060     * @throws IllegalArgumentException if any field is out of range
061     */
062    int parseInto(DateTimeParserBucket bucket, String text, int position);
063
064}