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/*
 * 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.lang3;

import java.io.Serializable;
import java.util.Iterator;
import java.util.NoSuchElementException;

/**
 * 

A contiguous range of characters, optionally negated.

* *

Instances are immutable.

* *

#ThreadSafe#

* @since 1.0 */ // TODO: This is no longer public and will be removed later as CharSet is moved // to depend on Range. final class CharRange implements Iterable, Serializable { /** * Required for serialization support. Lang version 2.0. * * @see java.io.Serializable */ private static final long serialVersionUID = 8270183163158333422L; /** The first character, inclusive, in the range. */ private final char start; /** The last character, inclusive, in the range. */ private final char end; /** True if the range is everything except the characters specified. */ private final boolean negated; /** Cached toString. */ private transient String iToString; /** *

Constructs a {@code CharRange} over a set of characters, * optionally negating the range.

* *

A negated range includes everything except that defined by the * start and end characters.

* *

If start and end are in the wrong order, they are reversed. * Thus {@code a-e} is the same as {@code e-a}.

* * @param start first character, inclusive, in this range * @param end last character, inclusive, in this range * @param negated true to express everything except the range */ private CharRange(char start, char end, final boolean negated) { super(); if (start > end) { final char temp = start; start = end; end = temp; } this.start = start; this.end = end; this.negated = negated; } /** *

Constructs a {@code CharRange} over a single character.

* * @param ch only character in this range * @return the new CharRange object * @see CharRange#CharRange(char, char, boolean) * @since 2.5 */ public static CharRange is(final char ch) { return new CharRange(ch, ch, false); } /** *

Constructs a negated {@code CharRange} over a single character.

* * @param ch only character in this range * @return the new CharRange object * @see CharRange#CharRange(char, char, boolean) * @since 2.5 */ public static CharRange isNot(final char ch) { return new CharRange(ch, ch, true); } /** *

Constructs a {@code CharRange} over a set of characters.

* * @param start first character, inclusive, in this range * @param end last character, inclusive, in this range * @return the new CharRange object * @see CharRange#CharRange(char, char, boolean) * @since 2.5 */ public static CharRange isIn(final char start, final char end) { return new CharRange(start, end, false); } /** *

Constructs a negated {@code CharRange} over a set of characters.

* * @param start first character, inclusive, in this range * @param end last character, inclusive, in this range * @return the new CharRange object * @see CharRange#CharRange(char, char, boolean) * @since 2.5 */ public static CharRange isNotIn(final char start, final char end) { return new CharRange(start, end, true); } // Accessors //----------------------------------------------------------------------- /** *

Gets the start character for this character range.

* * @return the start char (inclusive) */ public char getStart() { return this.start; } /** *

Gets the end character for this character range.

* * @return the end char (inclusive) */ public char getEnd() { return this.end; } /** *

Is this {@code CharRange} negated.

* *

A negated range includes everything except that defined by the * start and end characters.

* * @return {@code true} if negated */ public boolean isNegated() { return negated; } // Contains //----------------------------------------------------------------------- /** *

Is the character specified contained in this range.

* * @param ch the character to check * @return {@code true} if this range contains the input character */ public boolean contains(final char ch) { return (ch >= start && ch <= end) != negated; } /** *

Are all the characters of the passed in range contained in * this range.

* * @param range the range to check against * @return {@code true} if this range entirely contains the input range * @throws IllegalArgumentException if {@code null} input */ public boolean contains(final CharRange range) { Validate.isTrue(range != null, "The Range must not be null"); if (negated) { if (range.negated) { return start >= range.start && end <= range.end; } return range.end < start || range.start > end; } if (range.negated) { return start == 0 && end == Character.MAX_VALUE; } return start <= range.start && end >= range.end; } // Basics //----------------------------------------------------------------------- /** *

Compares two CharRange objects, returning true if they represent * exactly the same range of characters defined in the same way.

* * @param obj the object to compare to * @return true if equal */ @Override public boolean equals(final Object obj) { if (obj == this) { return true; } if (!(obj instanceof CharRange)) { return false; } final CharRange other = (CharRange) obj; return start == other.start && end == other.end && negated == other.negated; } /** *

Gets a hashCode compatible with the equals method.

* * @return a suitable hashCode */ @Override public int hashCode() { return 83 + start + 7 * end + (negated ? 1 : 0); } /** *

Gets a string representation of the character range.

* * @return string representation of this range */ @Override public String toString() { if (iToString == null) { final StringBuilder buf = new StringBuilder(4); if (isNegated()) { buf.append('^'); } buf.append(start); if (start != end) { buf.append('-'); buf.append(end); } iToString = buf.toString(); } return iToString; } // Expansions //----------------------------------------------------------------------- /** *

Returns an iterator which can be used to walk through the characters described by this range.

* *

#NotThreadSafe# the iterator is not thread-safe

* @return an iterator to the chars represented by this range * @since 2.5 */ @Override public Iterator iterator() { return new CharacterIterator(this); } /** * Character {@link Iterator}. *

#NotThreadSafe#

*/ private static class CharacterIterator implements Iterator { /** The current character */ private char current; private final CharRange range; private boolean hasNext; /** * Construct a new iterator for the character range. * * @param r The character range */ private CharacterIterator(final CharRange r) { range = r; hasNext = true; if (range.negated) { if (range.start == 0) { if (range.end == Character.MAX_VALUE) { // This range is an empty set hasNext = false; } else { current = (char) (range.end + 1); } } else { current = 0; } } else { current = range.start; } } /** * Prepare the next character in the range. */ private void prepareNext() { if (range.negated) { if (current == Character.MAX_VALUE) { hasNext = false; } else if (current + 1 == range.start) { if (range.end == Character.MAX_VALUE) { hasNext = false; } else { current = (char) (range.end + 1); } } else { current = (char) (current + 1); } } else if (current < range.end) { current = (char) (current + 1); } else { hasNext = false; } } /** * Has the iterator not reached the end character yet? * * @return {@code true} if the iterator has yet to reach the character date */ @Override public boolean hasNext() { return hasNext; } /** * Return the next character in the iteration * * @return {@code Character} for the next character */ @Override public Character next() { if (!hasNext) { throw new NoSuchElementException(); } final char cur = current; prepareNext(); return Character.valueOf(cur); } /** * Always throws UnsupportedOperationException. * * @throws UnsupportedOperationException * @see java.util.Iterator#remove() */ @Override public void remove() { throw new UnsupportedOperationException(); } } }




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