001////////////////////////////////////////////////////////////////////////////////
002// checkstyle: Checks Java source code for adherence to a set of rules.
003// Copyright (C) 2001-2022 the original author or authors.
004//
005// This library is free software; you can redistribute it and/or
006// modify it under the terms of the GNU Lesser General Public
007// License as published by the Free Software Foundation; either
008// version 2.1 of the License, or (at your option) any later version.
009//
010// This library is distributed in the hope that it will be useful,
011// but WITHOUT ANY WARRANTY; without even the implied warranty of
012// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
013// Lesser General Public License for more details.
014//
015// You should have received a copy of the GNU Lesser General Public
016// License along with this library; if not, write to the Free Software
017// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
018////////////////////////////////////////////////////////////////////////////////
019
020package com.puppycrawl.tools.checkstyle.utils;
021
022import java.util.Arrays;
023
024/**
025 * Contains utility methods for code point.
026 */
027public final class CodePointUtil {
028
029    /** Stop instances being created. **/
030    private CodePointUtil() {
031    }
032
033    /**
034     * Checks if given code point array is blank by either being empty,
035     * or contains only whitespace characters.
036     *
037     * @param codePoints The array of unicode code points of string to check.
038     * @return true if codePoints is blank.
039     */
040    public static boolean isBlank(int... codePoints) {
041        return hasWhitespaceBefore(codePoints.length, codePoints);
042    }
043
044    /**
045     * Checks if the given code point array contains only whitespace up to specified index.
046     *
047     * @param codePoints
048     *            array of Unicode code point of string to check
049     * @param index
050     *            index to check up to (exclusive)
051     * @return true if all code points preceding given index are whitespace
052     */
053    public static boolean hasWhitespaceBefore(int index, int... codePoints) {
054        return Arrays.stream(codePoints, 0, index)
055                .allMatch(Character::isWhitespace);
056    }
057
058    /**
059     * Removes trailing whitespaces.
060     *
061     * @param codePoints array of unicode code points
062     * @return unicode code points array with trailing whitespaces removed
063     */
064    public static int[] stripTrailing(int... codePoints) {
065        int lastIndex = codePoints.length;
066        while (lastIndex > 0 && CommonUtil.isCodePointWhitespace(codePoints, lastIndex - 1)) {
067            lastIndex--;
068        }
069        return Arrays.copyOfRange(codePoints, 0, lastIndex);
070    }
071
072    /**
073     * Removes leading whitespaces.
074     *
075     * @param codePoints array of unicode code points
076     * @return unicode code points array with leading whitespaces removed
077     */
078    public static int[] stripLeading(int... codePoints) {
079        int startIndex = 0;
080        while (startIndex < codePoints.length
081            && CommonUtil.isCodePointWhitespace(codePoints, startIndex)) {
082            startIndex++;
083        }
084        return Arrays.copyOfRange(codePoints, startIndex, codePoints.length);
085    }
086
087    /**
088     * Removes leading and trailing whitespaces.
089     *
090     * @param codePoints array of unicode code points
091     * @return unicode code points array with leading and trailing whitespaces removed
092     */
093    public static int[] trim(int... codePoints) {
094        final int[] strippedCodePoints = stripTrailing(codePoints);
095        return stripLeading(strippedCodePoints);
096    }
097
098    /**
099     * Tests if the unicode code points array
100     * ends with the specified suffix.
101     *
102     * @param suffix the suffix
103     * @param codePoints the array of unicode code points to check
104     * @return {@code true}, if the unicode code points array ends with provided suffix
105     */
106    public static boolean endsWith(int[] codePoints, String suffix) {
107        final int startIndex = codePoints.length - suffix.length();
108        return startIndex > -1 && Arrays.equals(Arrays
109                    .copyOfRange(codePoints, startIndex, codePoints.length),
110                    suffix.codePoints().toArray());
111    }
112}