| // Copyright (c) 2012, the Dart project authors. Please see the AUTHORS file |
| // for details. All rights reserved. Use of this source code is governed by a |
| // BSD-style license that can be found in the LICENSE file. |
| |
| /* |
| * 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 com.google.dart.compiler.util.apache; |
| |
| /** |
| * <p>Operations on char primitives and Character objects.</p> |
| * |
| * <p>This class tries to handle {@code null} input gracefully. |
| * An exception will not be thrown for a {@code null} input. |
| * Each method documents its behaviour in more detail.</p> |
| * <p> |
| * NOTICE: This file is modified copy of its original Apache library. |
| * It was moved to the different package, and changed to reduce number of dependencies. |
| * |
| * <p>#ThreadSafe#</p> |
| * @since 2.1 |
| * @version $Id: CharUtils.java 1158279 2011-08-16 14:06:45Z ggregory $ |
| */ |
| public class CharUtils { |
| |
| private static final String[] CHAR_STRING_ARRAY = new String[128]; |
| |
| /** |
| * {@code \u000a} linefeed LF ('\n'). |
| * |
| * @see <a href="http://java.sun.com/docs/books/jls/third_edition/html/lexical.html#101089">JLF: Escape Sequences |
| * for Character and String Literals</a> |
| * @since 2.2 |
| */ |
| public static final char LF = '\n'; |
| |
| /** |
| * {@code \u000d} carriage return CR ('\r'). |
| * |
| * @see <a href="http://java.sun.com/docs/books/jls/third_edition/html/lexical.html#101089">JLF: Escape Sequences |
| * for Character and String Literals</a> |
| * @since 2.2 |
| */ |
| public static final char CR = '\r'; |
| |
| |
| static { |
| for (char c = 0; c < CHAR_STRING_ARRAY.length; c++) { |
| CHAR_STRING_ARRAY[c] = String.valueOf(c); |
| } |
| } |
| |
| /** |
| * <p>{@code CharUtils} instances should NOT be constructed in standard programming. |
| * Instead, the class should be used as {@code CharUtils.toString('c');}.</p> |
| * |
| * <p>This constructor is public to permit tools that require a JavaBean instance |
| * to operate.</p> |
| */ |
| public CharUtils() { |
| super(); |
| } |
| |
| //----------------------------------------------------------------------- |
| /** |
| * <p>Converts the character to a Character.</p> |
| * |
| * <p>For ASCII 7 bit characters, this uses a cache that will return the |
| * same Character object each time.</p> |
| * |
| * <pre> |
| * CharUtils.toCharacterObject(' ') = ' ' |
| * CharUtils.toCharacterObject('A') = 'A' |
| * </pre> |
| * |
| * @deprecated Java 5 introduced {@link Character#valueOf(char)} which caches chars 0 through 127. |
| * @param ch the character to convert |
| * @return a Character of the specified character |
| */ |
| @Deprecated |
| public static Character toCharacterObject(char ch) { |
| return Character.valueOf(ch); |
| } |
| |
| /** |
| * <p>Converts the String to a Character using the first character, returning |
| * null for empty Strings.</p> |
| * |
| * <p>For ASCII 7 bit characters, this uses a cache that will return the |
| * same Character object each time.</p> |
| * |
| * <pre> |
| * CharUtils.toCharacterObject(null) = null |
| * CharUtils.toCharacterObject("") = null |
| * CharUtils.toCharacterObject("A") = 'A' |
| * CharUtils.toCharacterObject("BA") = 'B' |
| * </pre> |
| * |
| * @param str the character to convert |
| * @return the Character value of the first letter of the String |
| */ |
| public static Character toCharacterObject(String str) { |
| if (StringUtils.isEmpty(str)) { |
| return null; |
| } |
| return Character.valueOf(str.charAt(0)); |
| } |
| |
| //----------------------------------------------------------------------- |
| /** |
| * <p>Converts the Character to a char throwing an exception for {@code null}.</p> |
| * |
| * <pre> |
| * CharUtils.toChar(' ') = ' ' |
| * CharUtils.toChar('A') = 'A' |
| * CharUtils.toChar(null) throws IllegalArgumentException |
| * </pre> |
| * |
| * @param ch the character to convert |
| * @return the char value of the Character |
| * @throws IllegalArgumentException if the Character is null |
| */ |
| public static char toChar(Character ch) { |
| if (ch == null) { |
| throw new IllegalArgumentException("The Character must not be null"); |
| } |
| return ch.charValue(); |
| } |
| |
| /** |
| * <p>Converts the Character to a char handling {@code null}.</p> |
| * |
| * <pre> |
| * CharUtils.toChar(null, 'X') = 'X' |
| * CharUtils.toChar(' ', 'X') = ' ' |
| * CharUtils.toChar('A', 'X') = 'A' |
| * </pre> |
| * |
| * @param ch the character to convert |
| * @param defaultValue the value to use if the Character is null |
| * @return the char value of the Character or the default if null |
| */ |
| public static char toChar(Character ch, char defaultValue) { |
| if (ch == null) { |
| return defaultValue; |
| } |
| return ch.charValue(); |
| } |
| |
| //----------------------------------------------------------------------- |
| /** |
| * <p>Converts the String to a char using the first character, throwing |
| * an exception on empty Strings.</p> |
| * |
| * <pre> |
| * CharUtils.toChar("A") = 'A' |
| * CharUtils.toChar("BA") = 'B' |
| * CharUtils.toChar(null) throws IllegalArgumentException |
| * CharUtils.toChar("") throws IllegalArgumentException |
| * </pre> |
| * |
| * @param str the character to convert |
| * @return the char value of the first letter of the String |
| * @throws IllegalArgumentException if the String is empty |
| */ |
| public static char toChar(String str) { |
| if (StringUtils.isEmpty(str)) { |
| throw new IllegalArgumentException("The String must not be empty"); |
| } |
| return str.charAt(0); |
| } |
| |
| /** |
| * <p>Converts the String to a char using the first character, defaulting |
| * the value on empty Strings.</p> |
| * |
| * <pre> |
| * CharUtils.toChar(null, 'X') = 'X' |
| * CharUtils.toChar("", 'X') = 'X' |
| * CharUtils.toChar("A", 'X') = 'A' |
| * CharUtils.toChar("BA", 'X') = 'B' |
| * </pre> |
| * |
| * @param str the character to convert |
| * @param defaultValue the value to use if the Character is null |
| * @return the char value of the first letter of the String or the default if null |
| */ |
| public static char toChar(String str, char defaultValue) { |
| if (StringUtils.isEmpty(str)) { |
| return defaultValue; |
| } |
| return str.charAt(0); |
| } |
| |
| //----------------------------------------------------------------------- |
| /** |
| * <p>Converts the character to the Integer it represents, throwing an |
| * exception if the character is not numeric.</p> |
| * |
| * <p>This method coverts the char '1' to the int 1 and so on.</p> |
| * |
| * <pre> |
| * CharUtils.toIntValue('3') = 3 |
| * CharUtils.toIntValue('A') throws IllegalArgumentException |
| * </pre> |
| * |
| * @param ch the character to convert |
| * @return the int value of the character |
| * @throws IllegalArgumentException if the character is not ASCII numeric |
| */ |
| public static int toIntValue(char ch) { |
| if (isAsciiNumeric(ch) == false) { |
| throw new IllegalArgumentException("The character " + ch + " is not in the range '0' - '9'"); |
| } |
| return ch - 48; |
| } |
| |
| /** |
| * <p>Converts the character to the Integer it represents, throwing an |
| * exception if the character is not numeric.</p> |
| * |
| * <p>This method coverts the char '1' to the int 1 and so on.</p> |
| * |
| * <pre> |
| * CharUtils.toIntValue('3', -1) = 3 |
| * CharUtils.toIntValue('A', -1) = -1 |
| * </pre> |
| * |
| * @param ch the character to convert |
| * @param defaultValue the default value to use if the character is not numeric |
| * @return the int value of the character |
| */ |
| public static int toIntValue(char ch, int defaultValue) { |
| if (isAsciiNumeric(ch) == false) { |
| return defaultValue; |
| } |
| return ch - 48; |
| } |
| |
| /** |
| * <p>Converts the character to the Integer it represents, throwing an |
| * exception if the character is not numeric.</p> |
| * |
| * <p>This method coverts the char '1' to the int 1 and so on.</p> |
| * |
| * <pre> |
| * CharUtils.toIntValue('3') = 3 |
| * CharUtils.toIntValue(null) throws IllegalArgumentException |
| * CharUtils.toIntValue('A') throws IllegalArgumentException |
| * </pre> |
| * |
| * @param ch the character to convert, not null |
| * @return the int value of the character |
| * @throws IllegalArgumentException if the Character is not ASCII numeric or is null |
| */ |
| public static int toIntValue(Character ch) { |
| if (ch == null) { |
| throw new IllegalArgumentException("The character must not be null"); |
| } |
| return toIntValue(ch.charValue()); |
| } |
| |
| /** |
| * <p>Converts the character to the Integer it represents, throwing an |
| * exception if the character is not numeric.</p> |
| * |
| * <p>This method coverts the char '1' to the int 1 and so on.</p> |
| * |
| * <pre> |
| * CharUtils.toIntValue(null, -1) = -1 |
| * CharUtils.toIntValue('3', -1) = 3 |
| * CharUtils.toIntValue('A', -1) = -1 |
| * </pre> |
| * |
| * @param ch the character to convert |
| * @param defaultValue the default value to use if the character is not numeric |
| * @return the int value of the character |
| */ |
| public static int toIntValue(Character ch, int defaultValue) { |
| if (ch == null) { |
| return defaultValue; |
| } |
| return toIntValue(ch.charValue(), defaultValue); |
| } |
| |
| //----------------------------------------------------------------------- |
| /** |
| * <p>Converts the character to a String that contains the one character.</p> |
| * |
| * <p>For ASCII 7 bit characters, this uses a cache that will return the |
| * same String object each time.</p> |
| * |
| * <pre> |
| * CharUtils.toString(' ') = " " |
| * CharUtils.toString('A') = "A" |
| * </pre> |
| * |
| * @param ch the character to convert |
| * @return a String containing the one specified character |
| */ |
| public static String toString(char ch) { |
| if (ch < 128) { |
| return CHAR_STRING_ARRAY[ch]; |
| } |
| return new String(new char[] {ch}); |
| } |
| |
| /** |
| * <p>Converts the character to a String that contains the one character.</p> |
| * |
| * <p>For ASCII 7 bit characters, this uses a cache that will return the |
| * same String object each time.</p> |
| * |
| * <p>If {@code null} is passed in, {@code null} will be returned.</p> |
| * |
| * <pre> |
| * CharUtils.toString(null) = null |
| * CharUtils.toString(' ') = " " |
| * CharUtils.toString('A') = "A" |
| * </pre> |
| * |
| * @param ch the character to convert |
| * @return a String containing the one specified character |
| */ |
| public static String toString(Character ch) { |
| if (ch == null) { |
| return null; |
| } |
| return toString(ch.charValue()); |
| } |
| |
| //-------------------------------------------------------------------------- |
| /** |
| * <p>Converts the string to the Unicode format '\u0020'.</p> |
| * |
| * <p>This format is the Java source code format.</p> |
| * |
| * <pre> |
| * CharUtils.unicodeEscaped(' ') = "\u0020" |
| * CharUtils.unicodeEscaped('A') = "\u0041" |
| * </pre> |
| * |
| * @param ch the character to convert |
| * @return the escaped Unicode string |
| */ |
| public static String unicodeEscaped(char ch) { |
| if (ch < 0x10) { |
| return "\\u000" + Integer.toHexString(ch); |
| } else if (ch < 0x100) { |
| return "\\u00" + Integer.toHexString(ch); |
| } else if (ch < 0x1000) { |
| return "\\u0" + Integer.toHexString(ch); |
| } |
| return "\\u" + Integer.toHexString(ch); |
| } |
| |
| /** |
| * <p>Converts the string to the Unicode format '\u0020'.</p> |
| * |
| * <p>This format is the Java source code format.</p> |
| * |
| * <p>If {@code null} is passed in, {@code null} will be returned.</p> |
| * |
| * <pre> |
| * CharUtils.unicodeEscaped(null) = null |
| * CharUtils.unicodeEscaped(' ') = "\u0020" |
| * CharUtils.unicodeEscaped('A') = "\u0041" |
| * </pre> |
| * |
| * @param ch the character to convert, may be null |
| * @return the escaped Unicode string, null if null input |
| */ |
| public static String unicodeEscaped(Character ch) { |
| if (ch == null) { |
| return null; |
| } |
| return unicodeEscaped(ch.charValue()); |
| } |
| |
| //-------------------------------------------------------------------------- |
| /** |
| * <p>Checks whether the character is ASCII 7 bit.</p> |
| * |
| * <pre> |
| * CharUtils.isAscii('a') = true |
| * CharUtils.isAscii('A') = true |
| * CharUtils.isAscii('3') = true |
| * CharUtils.isAscii('-') = true |
| * CharUtils.isAscii('\n') = true |
| * CharUtils.isAscii('©') = false |
| * </pre> |
| * |
| * @param ch the character to check |
| * @return true if less than 128 |
| */ |
| public static boolean isAscii(char ch) { |
| return ch < 128; |
| } |
| |
| /** |
| * <p>Checks whether the character is ASCII 7 bit printable.</p> |
| * |
| * <pre> |
| * CharUtils.isAsciiPrintable('a') = true |
| * CharUtils.isAsciiPrintable('A') = true |
| * CharUtils.isAsciiPrintable('3') = true |
| * CharUtils.isAsciiPrintable('-') = true |
| * CharUtils.isAsciiPrintable('\n') = false |
| * CharUtils.isAsciiPrintable('©') = false |
| * </pre> |
| * |
| * @param ch the character to check |
| * @return true if between 32 and 126 inclusive |
| */ |
| public static boolean isAsciiPrintable(char ch) { |
| return ch >= 32 && ch < 127; |
| } |
| |
| /** |
| * <p>Checks whether the character is ASCII 7 bit control.</p> |
| * |
| * <pre> |
| * CharUtils.isAsciiControl('a') = false |
| * CharUtils.isAsciiControl('A') = false |
| * CharUtils.isAsciiControl('3') = false |
| * CharUtils.isAsciiControl('-') = false |
| * CharUtils.isAsciiControl('\n') = true |
| * CharUtils.isAsciiControl('©') = false |
| * </pre> |
| * |
| * @param ch the character to check |
| * @return true if less than 32 or equals 127 |
| */ |
| public static boolean isAsciiControl(char ch) { |
| return ch < 32 || ch == 127; |
| } |
| |
| /** |
| * <p>Checks whether the character is ASCII 7 bit alphabetic.</p> |
| * |
| * <pre> |
| * CharUtils.isAsciiAlpha('a') = true |
| * CharUtils.isAsciiAlpha('A') = true |
| * CharUtils.isAsciiAlpha('3') = false |
| * CharUtils.isAsciiAlpha('-') = false |
| * CharUtils.isAsciiAlpha('\n') = false |
| * CharUtils.isAsciiAlpha('©') = false |
| * </pre> |
| * |
| * @param ch the character to check |
| * @return true if between 65 and 90 or 97 and 122 inclusive |
| */ |
| public static boolean isAsciiAlpha(char ch) { |
| return (ch >= 'A' && ch <= 'Z') || (ch >= 'a' && ch <= 'z'); |
| } |
| |
| /** |
| * <p>Checks whether the character is ASCII 7 bit alphabetic upper case.</p> |
| * |
| * <pre> |
| * CharUtils.isAsciiAlphaUpper('a') = false |
| * CharUtils.isAsciiAlphaUpper('A') = true |
| * CharUtils.isAsciiAlphaUpper('3') = false |
| * CharUtils.isAsciiAlphaUpper('-') = false |
| * CharUtils.isAsciiAlphaUpper('\n') = false |
| * CharUtils.isAsciiAlphaUpper('©') = false |
| * </pre> |
| * |
| * @param ch the character to check |
| * @return true if between 65 and 90 inclusive |
| */ |
| public static boolean isAsciiAlphaUpper(char ch) { |
| return ch >= 'A' && ch <= 'Z'; |
| } |
| |
| /** |
| * <p>Checks whether the character is ASCII 7 bit alphabetic lower case.</p> |
| * |
| * <pre> |
| * CharUtils.isAsciiAlphaLower('a') = true |
| * CharUtils.isAsciiAlphaLower('A') = false |
| * CharUtils.isAsciiAlphaLower('3') = false |
| * CharUtils.isAsciiAlphaLower('-') = false |
| * CharUtils.isAsciiAlphaLower('\n') = false |
| * CharUtils.isAsciiAlphaLower('©') = false |
| * </pre> |
| * |
| * @param ch the character to check |
| * @return true if between 97 and 122 inclusive |
| */ |
| public static boolean isAsciiAlphaLower(char ch) { |
| return ch >= 'a' && ch <= 'z'; |
| } |
| |
| /** |
| * <p>Checks whether the character is ASCII 7 bit numeric.</p> |
| * |
| * <pre> |
| * CharUtils.isAsciiNumeric('a') = false |
| * CharUtils.isAsciiNumeric('A') = false |
| * CharUtils.isAsciiNumeric('3') = true |
| * CharUtils.isAsciiNumeric('-') = false |
| * CharUtils.isAsciiNumeric('\n') = false |
| * CharUtils.isAsciiNumeric('©') = false |
| * </pre> |
| * |
| * @param ch the character to check |
| * @return true if between 48 and 57 inclusive |
| */ |
| public static boolean isAsciiNumeric(char ch) { |
| return ch >= '0' && ch <= '9'; |
| } |
| |
| /** |
| * <p>Checks whether the character is ASCII 7 bit numeric.</p> |
| * |
| * <pre> |
| * CharUtils.isAsciiAlphanumeric('a') = true |
| * CharUtils.isAsciiAlphanumeric('A') = true |
| * CharUtils.isAsciiAlphanumeric('3') = true |
| * CharUtils.isAsciiAlphanumeric('-') = false |
| * CharUtils.isAsciiAlphanumeric('\n') = false |
| * CharUtils.isAsciiAlphanumeric('©') = false |
| * </pre> |
| * |
| * @param ch the character to check |
| * @return true if between 48 and 57 or 65 and 90 or 97 and 122 inclusive |
| */ |
| public static boolean isAsciiAlphanumeric(char ch) { |
| return (ch >= 'A' && ch <= 'Z') || (ch >= 'a' && ch <= 'z') || (ch >= '0' && ch <= '9'); |
| } |
| |
| } |
