/*
 * Copyright 2014 The Netty Project
 *
 * The Netty Project 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 io.netty.util;

import io.netty.util.internal.EmptyArrays;
import io.netty.util.internal.InternalThreadLocalMap;
import io.netty.util.internal.PlatformDependent;

import java.nio.ByteBuffer;
import java.nio.CharBuffer;
import java.nio.charset.Charset;
import java.nio.charset.CharsetEncoder;
import java.util.Arrays;
import java.util.Collection;
import java.util.List;
import java.util.regex.Pattern;
import java.util.regex.PatternSyntaxException;

import static io.netty.util.internal.MathUtil.isOutOfBounds;
import static io.netty.util.internal.ObjectUtil.checkNotNull;

A string which has been encoded into a character encoding whose character always takes a single byte, similarly to ASCII. It internally keeps its content in a byte array unlike String, which uses a character array, for reduced memory footprint and faster data transfer from/to byte-based data structures such as a byte array and ByteBuffer. It is often used in conjunction with Headers that require a CharSequence. 
 This class was designed to provide an immutable array of bytes, and caches some internal state based upon the value of this array. However underlying access to this byte array is provided via not copying the array on construction or array(). If any changes are made to the underlying byte array it is the user's responsibility to call arrayChanged() so the state of this class can be reset. /**
 * A string which has been encoded into a character encoding whose character always takes a single byte, similarly to
 * ASCII. It internally keeps its content in a byte array unlike {@link String}, which uses a character array, for
 * reduced memory footprint and faster data transfer from/to byte-based data structures such as a byte array and
 * {@link ByteBuffer}. It is often used in conjunction with {@code Headers} that require a {@link CharSequence}.
 * <p>
 * This class was designed to provide an immutable array of bytes, and caches some internal state based upon the value
 * of this array. However underlying access to this byte array is provided via not copying the array on construction or
 * {@link #array()}. If any changes are made to the underlying byte array it is the user's responsibility to call
 * {@link #arrayChanged()} so the state of this class can be reset.
 */
public final class AsciiString implements CharSequence, Comparable<CharSequence> {
    public static final AsciiString EMPTY_STRING = cached("");
    private static final char MAX_CHAR_VALUE = 255;

    public static final int INDEX_NOT_FOUND = -1;

    
If this value is modified outside the constructor then call arrayChanged(). /**
     * If this value is modified outside the constructor then call {@link #arrayChanged()}.
     */
    private final byte[] value;
    
Offset into value that all operations should use when acting upon value. /**
     * Offset into {@link #value} that all operations should use when acting upon {@link #value}.
     */
    private final int offset;
    
Length in bytes for value that we care about. This is independent from value.length because we may be looking at a subsection of the array. /**
     * Length in bytes for {@link #value} that we care about. This is independent from {@code value.length}
     * because we may be looking at a subsection of the array.
     */
    private final int length;
    
The hash code is cached after it is first computed. It can be reset with arrayChanged(). /**
     * The hash code is cached after it is first computed. It can be reset with {@link #arrayChanged()}.
     */
    private int hash;
    
Used to cache the toString() value. /**
     * Used to cache the {@link #toString()} value.
     */
    private String string;

    
Initialize this byte string based upon a byte array. A copy will be made.
/**
     * Initialize this byte string based upon a byte array. A copy will be made.
     */
    public AsciiString(byte[] value) {
        this(value, true);
    }

    
Initialize this byte string based upon a byte array. copy determines if a copy is made or the array is shared. /**
     * Initialize this byte string based upon a byte array.
     * {@code copy} determines if a copy is made or the array is shared.
     */
    public AsciiString(byte[] value, boolean copy) {
        this(value, 0, value.length, copy);
    }

    
Construct a new instance from a byte[] array. 
Params:
copy – true then a copy of the memory will be made. false the underlying memory will be shared./**
     * Construct a new instance from a {@code byte[]} array.
     * @param copy {@code true} then a copy of the memory will be made. {@code false} the underlying memory
     * will be shared.
     */
    public AsciiString(byte[] value, int start, int length, boolean copy) {
        if (copy) {
            this.value = Arrays.copyOfRange(value, start, start + length);
            this.offset = 0;
        } else {
            if (isOutOfBounds(start, length, value.length)) {
                throw new IndexOutOfBoundsException("expected: " + "0 <= start(" + start + ") <= start + length(" +
                        length + ") <= " + "value.length(" + value.length + ')');
            }
            this.value = value;
            this.offset = start;
        }
        this.length = length;
    }

    
Create a copy of the underlying storage from value. The copy will start at Buffer.position() and copy Buffer.remaining() bytes. /**
     * Create a copy of the underlying storage from {@code value}.
     * The copy will start at {@link ByteBuffer#position()} and copy {@link ByteBuffer#remaining()} bytes.
     */
    public AsciiString(ByteBuffer value) {
        this(value, true);
    }

    
Initialize an instance based upon the underlying storage from value. There is a potential to share the underlying array storage if ByteBuffer.hasArray() is true. if copy is true a copy will be made of the memory. if copy is false the underlying storage will be shared, if possible. /**
     * Initialize an instance based upon the underlying storage from {@code value}.
     * There is a potential to share the underlying array storage if {@link ByteBuffer#hasArray()} is {@code true}.
     * if {@code copy} is {@code true} a copy will be made of the memory.
     * if {@code copy} is {@code false} the underlying storage will be shared, if possible.
     */
    public AsciiString(ByteBuffer value, boolean copy) {
        this(value, value.position(), value.remaining(), copy);
    }

    
Initialize an AsciiString based upon the underlying storage from value. There is a potential to share the underlying array storage if ByteBuffer.hasArray() is true. if copy is true a copy will be made of the memory. if copy is false the underlying storage will be shared, if possible. /**
     * Initialize an {@link AsciiString} based upon the underlying storage from {@code value}.
     * There is a potential to share the underlying array storage if {@link ByteBuffer#hasArray()} is {@code true}.
     * if {@code copy} is {@code true} a copy will be made of the memory.
     * if {@code copy} is {@code false} the underlying storage will be shared, if possible.
     */
    public AsciiString(ByteBuffer value, int start, int length, boolean copy) {
        if (isOutOfBounds(start, length, value.capacity())) {
            throw new IndexOutOfBoundsException("expected: " + "0 <= start(" + start + ") <= start + length(" + length
                            + ") <= " + "value.capacity(" + value.capacity() + ')');
        }

        if (value.hasArray()) {
            if (copy) {
                final int bufferOffset = value.arrayOffset() + start;
                this.value = Arrays.copyOfRange(value.array(), bufferOffset, bufferOffset + length);
                offset = 0;
            } else {
                this.value = value.array();
                this.offset = start;
            }
        } else {
            this.value = new byte[length];
            int oldPos = value.position();
            value.get(this.value, 0, length);
            value.position(oldPos);
            this.offset = 0;
        }
        this.length = length;
    }

    
Create a copy of value into this instance assuming ASCII encoding. /**
     * Create a copy of {@code value} into this instance assuming ASCII encoding.
     */
    public AsciiString(char[] value) {
        this(value, 0, value.length);
    }

    
Create a copy of value into this instance assuming ASCII encoding. The copy will start at index start and copy length bytes. /**
     * Create a copy of {@code value} into this instance assuming ASCII encoding.
     * The copy will start at index {@code start} and copy {@code length} bytes.
     */
    public AsciiString(char[] value, int start, int length) {
        if (isOutOfBounds(start, length, value.length)) {
            throw new IndexOutOfBoundsException("expected: " + "0 <= start(" + start + ") <= start + length(" + length
                            + ") <= " + "value.length(" + value.length + ')');
        }

        this.value = new byte[length];
        for (int i = 0, j = start; i < length; i++, j++) {
            this.value[i] = c2b(value[j]);
        }
        this.offset = 0;
        this.length = length;
    }

    
Create a copy of value into this instance using the encoding type of charset. /**
     * Create a copy of {@code value} into this instance using the encoding type of {@code charset}.
     */
    public AsciiString(char[] value, Charset charset) {
        this(value, charset, 0, value.length);
    }

    
Create a copy of value into a this instance using the encoding type of charset. The copy will start at index start and copy length bytes. /**
     * Create a copy of {@code value} into a this instance using the encoding type of {@code charset}.
     * The copy will start at index {@code start} and copy {@code length} bytes.
     */
    public AsciiString(char[] value, Charset charset, int start, int length) {
        CharBuffer cbuf = CharBuffer.wrap(value, start, length);
        CharsetEncoder encoder = CharsetUtil.encoder(charset);
        ByteBuffer nativeBuffer = ByteBuffer.allocate((int) (encoder.maxBytesPerChar() * length));
        encoder.encode(cbuf, nativeBuffer, true);
        final int bufferOffset = nativeBuffer.arrayOffset();
        this.value = Arrays.copyOfRange(nativeBuffer.array(), bufferOffset, bufferOffset + nativeBuffer.position());
        this.offset = 0;
        this.length =  this.value.length;
    }

    
Create a copy of value into this instance assuming ASCII encoding. /**
     * Create a copy of {@code value} into this instance assuming ASCII encoding.
     */
    public AsciiString(CharSequence value) {
        this(value, 0, value.length());
    }

    
Create a copy of value into this instance assuming ASCII encoding. The copy will start at index start and copy length bytes. /**
     * Create a copy of {@code value} into this instance assuming ASCII encoding.
     * The copy will start at index {@code start} and copy {@code length} bytes.
     */
    public AsciiString(CharSequence value, int start, int length) {
        if (isOutOfBounds(start, length, value.length())) {
            throw new IndexOutOfBoundsException("expected: " + "0 <= start(" + start + ") <= start + length(" + length
                            + ") <= " + "value.length(" + value.length() + ')');
        }

        this.value = new byte[length];
        for (int i = 0, j = start; i < length; i++, j++) {
            this.value[i] = c2b(value.charAt(j));
        }
        this.offset = 0;
        this.length = length;
    }

    
Create a copy of value into this instance using the encoding type of charset. /**
     * Create a copy of {@code value} into this instance using the encoding type of {@code charset}.
     */
    public AsciiString(CharSequence value, Charset charset) {
        this(value, charset, 0, value.length());
    }

    
Create a copy of value into this instance using the encoding type of charset. The copy will start at index start and copy length bytes. /**
     * Create a copy of {@code value} into this instance using the encoding type of {@code charset}.
     * The copy will start at index {@code start} and copy {@code length} bytes.
     */
    public AsciiString(CharSequence value, Charset charset, int start, int length) {
        CharBuffer cbuf = CharBuffer.wrap(value, start, start + length);
        CharsetEncoder encoder = CharsetUtil.encoder(charset);
        ByteBuffer nativeBuffer = ByteBuffer.allocate((int) (encoder.maxBytesPerChar() * length));
        encoder.encode(cbuf, nativeBuffer, true);
        final int offset = nativeBuffer.arrayOffset();
        this.value = Arrays.copyOfRange(nativeBuffer.array(), offset, offset + nativeBuffer.position());
        this.offset = 0;
        this.length = this.value.length;
    }

    
Iterates over the readable bytes of this buffer with the specified processor in ascending order. 
Returns:
-1 if the processor iterated to or beyond the end of the readable bytes. The last-visited index If the ByteProcessor.process(byte) returned false./**
     * Iterates over the readable bytes of this buffer with the specified {@code processor} in ascending order.
     *
     * @return {@code -1} if the processor iterated to or beyond the end of the readable bytes.
     *         The last-visited index If the {@link ByteProcessor#process(byte)} returned {@code false}.
     */
    public int forEachByte(ByteProcessor visitor) throws Exception {
        return forEachByte0(0, length(), visitor);
    }

    
Iterates over the specified area of this buffer with the specified processor in ascending order. (i.e. index, (index + 1), .. (index + length - 1)). 
Returns:
-1 if the processor iterated to or beyond the end of the specified area. The last-visited index If the ByteProcessor.process(byte) returned false./**
     * Iterates over the specified area of this buffer with the specified {@code processor} in ascending order.
     * (i.e. {@code index}, {@code (index + 1)},  .. {@code (index + length - 1)}).
     *
     * @return {@code -1} if the processor iterated to or beyond the end of the specified area.
     *         The last-visited index If the {@link ByteProcessor#process(byte)} returned {@code false}.
     */
    public int forEachByte(int index, int length, ByteProcessor visitor) throws Exception {
        if (isOutOfBounds(index, length, length())) {
            throw new IndexOutOfBoundsException("expected: " + "0 <= index(" + index + ") <= start + length(" + length
                    + ") <= " + "length(" + length() + ')');
        }
        return forEachByte0(index, length, visitor);
    }

    private int forEachByte0(int index, int length, ByteProcessor visitor) throws Exception {
        final int len = offset + index + length;
        for (int i = offset + index; i < len; ++i) {
            if (!visitor.process(value[i])) {
                return i - offset;
            }
        }
        return -1;
    }

    
Iterates over the readable bytes of this buffer with the specified processor in descending order. 
Returns:
-1 if the processor iterated to or beyond the beginning of the readable bytes. The last-visited index If the ByteProcessor.process(byte) returned false./**
     * Iterates over the readable bytes of this buffer with the specified {@code processor} in descending order.
     *
     * @return {@code -1} if the processor iterated to or beyond the beginning of the readable bytes.
     *         The last-visited index If the {@link ByteProcessor#process(byte)} returned {@code false}.
     */
    public int forEachByteDesc(ByteProcessor visitor) throws Exception {
        return forEachByteDesc0(0, length(), visitor);
    }

    
Iterates over the specified area of this buffer with the specified processor in descending order. (i.e. (index + length - 1), (index + length - 2), ... index). 
Returns:
-1 if the processor iterated to or beyond the beginning of the specified area. The last-visited index If the ByteProcessor.process(byte) returned false./**
     * Iterates over the specified area of this buffer with the specified {@code processor} in descending order.
     * (i.e. {@code (index + length - 1)}, {@code (index + length - 2)}, ... {@code index}).
     *
     * @return {@code -1} if the processor iterated to or beyond the beginning of the specified area.
     *         The last-visited index If the {@link ByteProcessor#process(byte)} returned {@code false}.
     */
    public int forEachByteDesc(int index, int length, ByteProcessor visitor) throws Exception {
        if (isOutOfBounds(index, length, length())) {
            throw new IndexOutOfBoundsException("expected: " + "0 <= index(" + index + ") <= start + length(" + length
                    + ") <= " + "length(" + length() + ')');
        }
        return forEachByteDesc0(index, length, visitor);
    }

    private int forEachByteDesc0(int index, int length, ByteProcessor visitor) throws Exception {
        final int end = offset + index;
        for (int i = offset + index + length - 1; i >= end; --i) {
            if (!visitor.process(value[i])) {
                return i - offset;
            }
        }
        return -1;
    }

    public byte byteAt(int index) {
        // We must do a range check here to enforce the access does not go outside our sub region of the array.
        // We rely on the array access itself to pick up the array out of bounds conditions
        if (index < 0 || index >= length) {
            throw new IndexOutOfBoundsException("index: " + index + " must be in the range [0," + length + ")");
        }
        // Try to use unsafe to avoid double checking the index bounds
        if (PlatformDependent.hasUnsafe()) {
            return PlatformDependent.getByte(value, index + offset);
        }
        return value[index + offset];
    }

    
Determine if this instance has 0 length.
/**
     * Determine if this instance has 0 length.
     */
    public boolean isEmpty() {
        return length == 0;
    }

    
The length in bytes of this instance.
/**
     * The length in bytes of this instance.
     */
    @Override
    public int length() {
        return length;
    }

    
During normal use cases the AsciiString should be immutable, but if the underlying array is shared, and changes then this needs to be called. /**
     * During normal use cases the {@link AsciiString} should be immutable, but if the underlying array is shared,
     * and changes then this needs to be called.
     */
    public void arrayChanged() {
        string = null;
        hash = 0;
    }

    
This gives direct access to the underlying storage array. The toByteArray() should be preferred over this method. If the return value is changed then arrayChanged() must be called. 
See Also:
arrayOffset()
isEntireArrayUsed()/**
     * This gives direct access to the underlying storage array.
     * The {@link #toByteArray()} should be preferred over this method.
     * If the return value is changed then {@link #arrayChanged()} must be called.
     * @see #arrayOffset()
     * @see #isEntireArrayUsed()
     */
    public byte[] array() {
        return value;
    }

    
The offset into array() for which data for this ByteString begins. 
See Also:
array()
isEntireArrayUsed()/**
     * The offset into {@link #array()} for which data for this ByteString begins.
     * @see #array()
     * @see #isEntireArrayUsed()
     */
    public int arrayOffset() {
        return offset;
    }

    
Determine if the storage represented by array() is entirely used. 
See Also:
array()/**
     * Determine if the storage represented by {@link #array()} is entirely used.
     * @see #array()
     */
    public boolean isEntireArrayUsed() {
        return offset == 0 && length == value.length;
    }

    
Converts this string to a byte array.
/**
     * Converts this string to a byte array.
     */
    public byte[] toByteArray() {
        return toByteArray(0, length());
    }

    
Converts a subset of this string to a byte array. The subset is defined by the range [start, end). /**
     * Converts a subset of this string to a byte array.
     * The subset is defined by the range [{@code start}, {@code end}).
     */
    public byte[] toByteArray(int start, int end) {
        return Arrays.copyOfRange(value, start + offset, end + offset);
    }

    
Copies the content of this string to a byte array.
Params:
srcIdx – the starting offset of characters to copy.
dst – the destination byte array.
dstIdx – the starting offset in the destination byte array.
length – the number of characters to copy./**
     * Copies the content of this string to a byte array.
     *
     * @param srcIdx the starting offset of characters to copy.
     * @param dst the destination byte array.
     * @param dstIdx the starting offset in the destination byte array.
     * @param length the number of characters to copy.
     */
    public void copy(int srcIdx, byte[] dst, int dstIdx, int length) {
        if (isOutOfBounds(srcIdx, length, length())) {
            throw new IndexOutOfBoundsException("expected: " + "0 <= srcIdx(" + srcIdx + ") <= srcIdx + length("
                            + length + ") <= srcLen(" + length() + ')');
        }

        System.arraycopy(value, srcIdx + offset, checkNotNull(dst, "dst"), dstIdx, length);
    }

    @Override
    public char charAt(int index) {
        return b2c(byteAt(index));
    }

    
Determines if this String contains the sequence of characters in the CharSequence passed. 
Params:
cs – the character sequence to search for.
Returns:
true if the sequence of characters are contained in this string, otherwise false./**
     * Determines if this {@code String} contains the sequence of characters in the {@code CharSequence} passed.
     *
     * @param cs the character sequence to search for.
     * @return {@code true} if the sequence of characters are contained in this string, otherwise {@code false}.
     */
    public boolean contains(CharSequence cs) {
        return indexOf(cs) >= 0;
    }

    
Compares the specified string to this string using the ASCII values of the characters. Returns 0 if the strings
contain the same characters in the same order. Returns a negative integer if the first non-equal character in
this string has an ASCII value which is less than the ASCII value of the character at the same position in the
specified string, or if this string is a prefix of the specified string. Returns a positive integer if the first
non-equal character in this string has a ASCII value which is greater than the ASCII value of the character at
the same position in the specified string, or if the specified string is a prefix of this string.
Params:
string – the string to compare.
Throws:
NullPointerException – if string is null.
Returns:
0 if the strings are equal, a negative integer if this string is before the specified string, or a
        positive integer if this string is after the specified string./**
     * Compares the specified string to this string using the ASCII values of the characters. Returns 0 if the strings
     * contain the same characters in the same order. Returns a negative integer if the first non-equal character in
     * this string has an ASCII value which is less than the ASCII value of the character at the same position in the
     * specified string, or if this string is a prefix of the specified string. Returns a positive integer if the first
     * non-equal character in this string has a ASCII value which is greater than the ASCII value of the character at
     * the same position in the specified string, or if the specified string is a prefix of this string.
     *
     * @param string the string to compare.
     * @return 0 if the strings are equal, a negative integer if this string is before the specified string, or a
     *         positive integer if this string is after the specified string.
     * @throws NullPointerException if {@code string} is {@code null}.
     */
    @Override
    public int compareTo(CharSequence string) {
        if (this == string) {
            return 0;
        }

        int result;
        int length1 = length();
        int length2 = string.length();
        int minLength = Math.min(length1, length2);
        for (int i = 0, j = arrayOffset(); i < minLength; i++, j++) {
            result = b2c(value[j]) - string.charAt(i);
            if (result != 0) {
                return result;
            }
        }

        return length1 - length2;
    }

    
Concatenates this string and the specified string.
Params:
string – the string to concatenate
Returns:
a new string which is the concatenation of this string and the specified string./**
     * Concatenates this string and the specified string.
     *
     * @param string the string to concatenate
     * @return a new string which is the concatenation of this string and the specified string.
     */
    public AsciiString concat(CharSequence string) {
        int thisLen = length();
        int thatLen = string.length();
        if (thatLen == 0) {
            return this;
        }

        if (string.getClass() == AsciiString.class) {
            AsciiString that = (AsciiString) string;
            if (isEmpty()) {
                return that;
            }

            byte[] newValue = new byte[thisLen + thatLen];
            System.arraycopy(value, arrayOffset(), newValue, 0, thisLen);
            System.arraycopy(that.value, that.arrayOffset(), newValue, thisLen, thatLen);
            return new AsciiString(newValue, false);
        }

        if (isEmpty()) {
            return new AsciiString(string);
        }

        byte[] newValue = new byte[thisLen + thatLen];
        System.arraycopy(value, arrayOffset(), newValue, 0, thisLen);
        for (int i = thisLen, j = 0; i < newValue.length; i++, j++) {
            newValue[i] = c2b(string.charAt(j));
        }

        return new AsciiString(newValue, false);
    }

    
Compares the specified string to this string to determine if the specified string is a suffix.
Params:
suffix – the suffix to look for.
Throws:
NullPointerException – if suffix is null.
Returns:
true if the specified string is a suffix of this string, false otherwise./**
     * Compares the specified string to this string to determine if the specified string is a suffix.
     *
     * @param suffix the suffix to look for.
     * @return {@code true} if the specified string is a suffix of this string, {@code false} otherwise.
     * @throws NullPointerException if {@code suffix} is {@code null}.
     */
    public boolean endsWith(CharSequence suffix) {
        int suffixLen = suffix.length();
        return regionMatches(length() - suffixLen, suffix, 0, suffixLen);
    }

    
Compares the specified string to this string ignoring the case of the characters and returns true if they are
equal.
Params:
string – the string to compare.
Returns:
true if the specified string is equal to this string, false otherwise./**
     * Compares the specified string to this string ignoring the case of the characters and returns true if they are
     * equal.
     *
     * @param string the string to compare.
     * @return {@code true} if the specified string is equal to this string, {@code false} otherwise.
     */
    public boolean contentEqualsIgnoreCase(CharSequence string) {
        if (string == null || string.length() != length()) {
            return false;
        }

        if (string.getClass() == AsciiString.class) {
            AsciiString rhs = (AsciiString) string;
            for (int i = arrayOffset(), j = rhs.arrayOffset(); i < length(); ++i, ++j) {
                if (!equalsIgnoreCase(value[i], rhs.value[j])) {
                    return false;
                }
            }
            return true;
        }

        for (int i = arrayOffset(), j = 0; i < length(); ++i, ++j) {
            if (!equalsIgnoreCase(b2c(value[i]), string.charAt(j))) {
                return false;
            }
        }
        return true;
    }

    
Copies the characters in this string to a character array.
Returns:
a character array containing the characters of this string./**
     * Copies the characters in this string to a character array.
     *
     * @return a character array containing the characters of this string.
     */
    public char[] toCharArray() {
        return toCharArray(0, length());
    }

    
Copies the characters in this string to a character array.
Returns:
a character array containing the characters of this string./**
     * Copies the characters in this string to a character array.
     *
     * @return a character array containing the characters of this string.
     */
    public char[] toCharArray(int start, int end) {
        int length = end - start;
        if (length == 0) {
            return EmptyArrays.EMPTY_CHARS;
        }

        if (isOutOfBounds(start, length, length())) {
            throw new IndexOutOfBoundsException("expected: " + "0 <= start(" + start + ") <= srcIdx + length("
                            + length + ") <= srcLen(" + length() + ')');
        }

        final char[] buffer = new char[length];
        for (int i = 0, j = start + arrayOffset(); i < length; i++, j++) {
            buffer[i] = b2c(value[j]);
        }
        return buffer;
    }

    
Copied the content of this string to a character array.
Params:
srcIdx – the starting offset of characters to copy.
dst – the destination character array.
dstIdx – the starting offset in the destination byte array.
length – the number of characters to copy./**
     * Copied the content of this string to a character array.
     *
     * @param srcIdx the starting offset of characters to copy.
     * @param dst the destination character array.
     * @param dstIdx the starting offset in the destination byte array.
     * @param length the number of characters to copy.
     */
    public void copy(int srcIdx, char[] dst, int dstIdx, int length) {
        if (dst == null) {
            throw new NullPointerException("dst");
        }

        if (isOutOfBounds(srcIdx, length, length())) {
            throw new IndexOutOfBoundsException("expected: " + "0 <= srcIdx(" + srcIdx + ") <= srcIdx + length("
                            + length + ") <= srcLen(" + length() + ')');
        }

        final int dstEnd = dstIdx + length;
        for (int i = dstIdx, j = srcIdx + arrayOffset(); i < dstEnd; i++, j++) {
            dst[i] = b2c(value[j]);
        }
    }

    
Copies a range of characters into a new string.
Params:
start – the offset of the first character (inclusive).
Throws:
IndexOutOfBoundsException – if start < 0 or start > length().
Returns:
a new string containing the characters from start to the end of the string./**
     * Copies a range of characters into a new string.
     * @param start the offset of the first character (inclusive).
     * @return a new string containing the characters from start to the end of the string.
     * @throws IndexOutOfBoundsException if {@code start < 0} or {@code start > length()}.
     */
    public AsciiString subSequence(int start) {
        return subSequence(start, length());
    }

    
Copies a range of characters into a new string.
Params:
start – the offset of the first character (inclusive).
end – The index to stop at (exclusive).
Throws:
IndexOutOfBoundsException – if start < 0 or start > length().
Returns:
a new string containing the characters from start to the end of the string./**
     * Copies a range of characters into a new string.
     * @param start the offset of the first character (inclusive).
     * @param end The index to stop at (exclusive).
     * @return a new string containing the characters from start to the end of the string.
     * @throws IndexOutOfBoundsException if {@code start < 0} or {@code start > length()}.
     */
    @Override
    public AsciiString subSequence(int start, int end) {
       return subSequence(start, end, true);
    }

    
Either copy or share a subset of underlying sub-sequence of bytes.
Params:
start – the offset of the first character (inclusive).
end – The index to stop at (exclusive).
copy – If true then a copy of the underlying storage will be made. If false then the underlying storage will be shared.
Throws:
IndexOutOfBoundsException – if start < 0 or start > length().
Returns:
a new string containing the characters from start to the end of the string./**
     * Either copy or share a subset of underlying sub-sequence of bytes.
     * @param start the offset of the first character (inclusive).
     * @param end The index to stop at (exclusive).
     * @param copy If {@code true} then a copy of the underlying storage will be made.
     * If {@code false} then the underlying storage will be shared.
     * @return a new string containing the characters from start to the end of the string.
     * @throws IndexOutOfBoundsException if {@code start < 0} or {@code start > length()}.
     */
    public AsciiString subSequence(int start, int end, boolean copy) {
        if (isOutOfBounds(start, end - start, length())) {
            throw new IndexOutOfBoundsException("expected: 0 <= start(" + start + ") <= end (" + end + ") <= length("
                            + length() + ')');
        }

        if (start == 0 && end == length()) {
            return this;
        }

        if (end == start) {
            return EMPTY_STRING;
        }

        return new AsciiString(value, start + offset, end - start, copy);
    }

    
Searches in this string for the first index of the specified string. The search for the string starts at the
beginning and moves towards the end of this string.
Params:
string – the string to find.
Throws:
NullPointerException – if string is null.
Returns:
the index of the first character of the specified string in this string, -1 if the specified string is
        not a substring./**
     * Searches in this string for the first index of the specified string. The search for the string starts at the
     * beginning and moves towards the end of this string.
     *
     * @param string the string to find.
     * @return the index of the first character of the specified string in this string, -1 if the specified string is
     *         not a substring.
     * @throws NullPointerException if {@code string} is {@code null}.
     */
    public int indexOf(CharSequence string) {
        return indexOf(string, 0);
    }

    
Searches in this string for the index of the specified string. The search for the string starts at the specified
offset and moves towards the end of this string.
Params:
subString – the string to find.
start – the starting offset.
Throws:
NullPointerException – if subString is null.
Returns:
the index of the first character of the specified string in this string, -1 if the specified string is
        not a substring./**
     * Searches in this string for the index of the specified string. The search for the string starts at the specified
     * offset and moves towards the end of this string.
     *
     * @param subString the string to find.
     * @param start the starting offset.
     * @return the index of the first character of the specified string in this string, -1 if the specified string is
     *         not a substring.
     * @throws NullPointerException if {@code subString} is {@code null}.
     */
    public int indexOf(CharSequence subString, int start) {
        final int subCount = subString.length();
        if (start < 0) {
            start = 0;
        }
        if (subCount <= 0) {
            return start < length ? start : length;
        }
        if (subCount > length - start) {
            return INDEX_NOT_FOUND;
        }

        final char firstChar = subString.charAt(0);
        if (firstChar > MAX_CHAR_VALUE) {
            return INDEX_NOT_FOUND;
        }
        final byte firstCharAsByte = c2b0(firstChar);
        final int len = offset + length - subCount;
        for (int i = start + offset; i <= len; ++i) {
            if (value[i] == firstCharAsByte) {
                int o1 = i, o2 = 0;
                while (++o2 < subCount && b2c(value[++o1]) == subString.charAt(o2)) {
                    // Intentionally empty
                }
                if (o2 == subCount) {
                    return i - offset;
                }
            }
        }
        return INDEX_NOT_FOUND;
    }

    
Searches in this string for the index of the specified char ch. The search for the char starts at the specified offset start and moves towards the end of this string. 
Params:
ch – the char to find.
start – the starting offset.
Returns:
the index of the first occurrence of the specified char ch in this string, -1 if found no occurrence./**
     * Searches in this string for the index of the specified char {@code ch}.
     * The search for the char starts at the specified offset {@code start} and moves towards the end of this string.
     *
     * @param ch the char to find.
     * @param start the starting offset.
     * @return the index of the first occurrence of the specified char {@code ch} in this string,
     * -1 if found no occurrence.
     */
    public int indexOf(char ch, int start) {
        if (ch > MAX_CHAR_VALUE) {
            return INDEX_NOT_FOUND;
        }

        if (start < 0) {
            start = 0;
        }

        final byte chAsByte = c2b0(ch);
        final int len = offset + start + length;
        for (int i = start + offset; i < len; ++i) {
            if (value[i] == chAsByte) {
                return i - offset;
            }
        }
        return INDEX_NOT_FOUND;
    }

    
Searches in this string for the last index of the specified string. The search for the string starts at the end
and moves towards the beginning of this string.
Params:
string – the string to find.
Throws:
NullPointerException – if string is null.
Returns:
the index of the first character of the specified string in this string, -1 if the specified string is
        not a substring./**
     * Searches in this string for the last index of the specified string. The search for the string starts at the end
     * and moves towards the beginning of this string.
     *
     * @param string the string to find.
     * @return the index of the first character of the specified string in this string, -1 if the specified string is
     *         not a substring.
     * @throws NullPointerException if {@code string} is {@code null}.
     */
    public int lastIndexOf(CharSequence string) {
        // Use count instead of count - 1 so lastIndexOf("") answers count
        return lastIndexOf(string, length());
    }

    
Searches in this string for the index of the specified string. The search for the string starts at the specified
offset and moves towards the beginning of this string.
Params:
subString – the string to find.
start – the starting offset.
Throws:
NullPointerException – if subString is null.
Returns:
the index of the first character of the specified string in this string , -1 if the specified string is
        not a substring./**
     * Searches in this string for the index of the specified string. The search for the string starts at the specified
     * offset and moves towards the beginning of this string.
     *
     * @param subString the string to find.
     * @param start the starting offset.
     * @return the index of the first character of the specified string in this string , -1 if the specified string is
     *         not a substring.
     * @throws NullPointerException if {@code subString} is {@code null}.
     */
    public int lastIndexOf(CharSequence subString, int start) {
        final int subCount = subString.length();
        if (start < 0) {
            start = 0;
        }
        if (subCount <= 0) {
            return start < length ? start : length;
        }
        if (subCount > length - start) {
            return INDEX_NOT_FOUND;
        }

        final char firstChar = subString.charAt(0);
        if (firstChar > MAX_CHAR_VALUE) {
            return INDEX_NOT_FOUND;
        }
        final byte firstCharAsByte = c2b0(firstChar);
        final int end = offset + start;
        for (int i = offset + length - subCount; i >= end; --i) {
            if (value[i] == firstCharAsByte) {
                int o1 = i, o2 = 0;
                while (++o2 < subCount && b2c(value[++o1]) == subString.charAt(o2)) {
                    // Intentionally empty
                }
                if (o2 == subCount) {
                    return i - offset;
                }
            }
        }
        return INDEX_NOT_FOUND;
    }

    
Compares the specified string to this string and compares the specified range of characters to determine if they
are the same.
Params:
thisStart – the starting offset in this string.
string – the string to compare.
start – the starting offset in the specified string.
length – the number of characters to compare.
Throws:
NullPointerException – if string is null.
Returns:
true if the ranges of characters are equal, false otherwise/**
     * Compares the specified string to this string and compares the specified range of characters to determine if they
     * are the same.
     *
     * @param thisStart the starting offset in this string.
     * @param string the string to compare.
     * @param start the starting offset in the specified string.
     * @param length the number of characters to compare.
     * @return {@code true} if the ranges of characters are equal, {@code false} otherwise
     * @throws NullPointerException if {@code string} is {@code null}.
     */
    public boolean regionMatches(int thisStart, CharSequence string, int start, int length) {
        if (string == null) {
            throw new NullPointerException("string");
        }

        if (start < 0 || string.length() - start < length) {
            return false;
        }

        final int thisLen = length();
        if (thisStart < 0 || thisLen - thisStart < length) {
            return false;
        }

        if (length <= 0) {
            return true;
        }

        final int thatEnd = start + length;
        for (int i = start, j = thisStart + arrayOffset(); i < thatEnd; i++, j++) {
            if (b2c(value[j]) != string.charAt(i)) {
                return false;
            }
        }
        return true;
    }

    
Compares the specified string to this string and compares the specified range of characters to determine if they
are the same. When ignoreCase is true, the case of the characters is ignored during the comparison.
Params:
ignoreCase – specifies if case should be ignored.
thisStart – the starting offset in this string.
string – the string to compare.
start – the starting offset in the specified string.
length – the number of characters to compare.
Throws:
NullPointerException – if string is null.
Returns:
true if the ranges of characters are equal, false otherwise./**
     * Compares the specified string to this string and compares the specified range of characters to determine if they
     * are the same. When ignoreCase is true, the case of the characters is ignored during the comparison.
     *
     * @param ignoreCase specifies if case should be ignored.
     * @param thisStart the starting offset in this string.
     * @param string the string to compare.
     * @param start the starting offset in the specified string.
     * @param length the number of characters to compare.
     * @return {@code true} if the ranges of characters are equal, {@code false} otherwise.
     * @throws NullPointerException if {@code string} is {@code null}.
     */
    public boolean regionMatches(boolean ignoreCase, int thisStart, CharSequence string, int start, int length) {
        if (!ignoreCase) {
            return regionMatches(thisStart, string, start, length);
        }

        if (string == null) {
            throw new NullPointerException("string");
        }

        final int thisLen = length();
        if (thisStart < 0 || length > thisLen - thisStart) {
            return false;
        }
        if (start < 0 || length > string.length() - start) {
            return false;
        }

        thisStart += arrayOffset();
        final int thisEnd = thisStart + length;
        while (thisStart < thisEnd) {
            if (!equalsIgnoreCase(b2c(value[thisStart++]), string.charAt(start++))) {
                return false;
            }
        }
        return true;
    }

    
Copies this string replacing occurrences of the specified character with another character.
Params:
oldChar – the character to replace.
newChar – the replacement character.
Returns:
a new string with occurrences of oldChar replaced by newChar./**
     * Copies this string replacing occurrences of the specified character with another character.
     *
     * @param oldChar the character to replace.
     * @param newChar the replacement character.
     * @return a new string with occurrences of oldChar replaced by newChar.
     */
    public AsciiString replace(char oldChar, char newChar) {
        if (oldChar > MAX_CHAR_VALUE) {
            return this;
        }

        final byte oldCharAsByte = c2b0(oldChar);
        final byte newCharAsByte = c2b(newChar);
        final int len = offset + length;
        for (int i = offset; i < len; ++i) {
            if (value[i] == oldCharAsByte) {
                byte[] buffer = new byte[length()];
                System.arraycopy(value, offset, buffer, 0, i - offset);
                buffer[i - offset] = newCharAsByte;
                ++i;
                for (; i < len; ++i) {
                    byte oldValue = value[i];
                    buffer[i - offset] = oldValue != oldCharAsByte ? oldValue : newCharAsByte;
                }
                return new AsciiString(buffer, false);
            }
        }
        return this;
    }

    
Compares the specified string to this string to determine if the specified string is a prefix.
Params:
prefix – the string to look for.
Throws:
NullPointerException – if prefix is null.
Returns:
true if the specified string is a prefix of this string, false otherwise/**
     * Compares the specified string to this string to determine if the specified string is a prefix.
     *
     * @param prefix the string to look for.
     * @return {@code true} if the specified string is a prefix of this string, {@code false} otherwise
     * @throws NullPointerException if {@code prefix} is {@code null}.
     */
    public boolean startsWith(CharSequence prefix) {
        return startsWith(prefix, 0);
    }

    
Compares the specified string to this string, starting at the specified offset, to determine if the specified
string is a prefix.
Params:
prefix – the string to look for.
start – the starting offset.
Throws:
NullPointerException – if prefix is null.
Returns:
true if the specified string occurs in this string at the specified offset, false otherwise./**
     * Compares the specified string to this string, starting at the specified offset, to determine if the specified
     * string is a prefix.
     *
     * @param prefix the string to look for.
     * @param start the starting offset.
     * @return {@code true} if the specified string occurs in this string at the specified offset, {@code false}
     *         otherwise.
     * @throws NullPointerException if {@code prefix} is {@code null}.
     */
    public boolean startsWith(CharSequence prefix, int start) {
        return regionMatches(start, prefix, 0, prefix.length());
    }

    
Converts the characters in this string to lowercase, using the default Locale.
Returns:
a new string containing the lowercase characters equivalent to the characters in this string./**
     * Converts the characters in this string to lowercase, using the default Locale.
     *
     * @return a new string containing the lowercase characters equivalent to the characters in this string.
     */
    public AsciiString toLowerCase() {
        boolean lowercased = true;
        int i, j;
        final int len = length() + arrayOffset();
        for (i = arrayOffset(); i < len; ++i) {
            byte b = value[i];
            if (b >= 'A' && b <= 'Z') {
                lowercased = false;
                break;
            }
        }

        // Check if this string does not contain any uppercase characters.
        if (lowercased) {
            return this;
        }

        final byte[] newValue = new byte[length()];
        for (i = 0, j = arrayOffset(); i < newValue.length; ++i, ++j) {
            newValue[i] = toLowerCase(value[j]);
        }

        return new AsciiString(newValue, false);
    }

    
Converts the characters in this string to uppercase, using the default Locale.
Returns:
a new string containing the uppercase characters equivalent to the characters in this string./**
     * Converts the characters in this string to uppercase, using the default Locale.
     *
     * @return a new string containing the uppercase characters equivalent to the characters in this string.
     */
    public AsciiString toUpperCase() {
        boolean uppercased = true;
        int i, j;
        final int len = length() + arrayOffset();
        for (i = arrayOffset(); i < len; ++i) {
            byte b = value[i];
            if (b >= 'a' && b <= 'z') {
                uppercased = false;
                break;
            }
        }

        // Check if this string does not contain any lowercase characters.
        if (uppercased) {
            return this;
        }

        final byte[] newValue = new byte[length()];
        for (i = 0, j = arrayOffset(); i < newValue.length; ++i, ++j) {
            newValue[i] = toUpperCase(value[j]);
        }

        return new AsciiString(newValue, false);
    }

    
Copies this string removing white space characters from the beginning and end of the string, and tries not to
copy if possible.
Params:
c – The CharSequence to trim.
Returns:
a new string with characters <= \\u0020 removed from the beginning and the end./**
     * Copies this string removing white space characters from the beginning and end of the string, and tries not to
     * copy if possible.
     *
     * @param c The {@link CharSequence} to trim.
     * @return a new string with characters {@code <= \\u0020} removed from the beginning and the end.
     */
    public static CharSequence trim(CharSequence c) {
        if (c.getClass() == AsciiString.class) {
            return ((AsciiString) c).trim();
        }
        if (c instanceof String) {
            return ((String) c).trim();
        }
        int start = 0, last = c.length() - 1;
        int end = last;
        while (start <= end && c.charAt(start) <= ' ') {
            start++;
        }
        while (end >= start && c.charAt(end) <= ' ') {
            end--;
        }
        if (start == 0 && end == last) {
            return c;
        }
        return c.subSequence(start, end);
    }

    
Duplicates this string removing white space characters from the beginning and end of the
string, without copying.
Returns:
a new string with characters <= \\u0020 removed from the beginning and the end./**
     * Duplicates this string removing white space characters from the beginning and end of the
     * string, without copying.
     *
     * @return a new string with characters {@code <= \\u0020} removed from the beginning and the end.
     */
    public AsciiString trim() {
        int start = arrayOffset(), last = arrayOffset() + length() - 1;
        int end = last;
        while (start <= end && value[start] <= ' ') {
            start++;
        }
        while (end >= start && value[end] <= ' ') {
            end--;
        }
        if (start == 0 && end == last) {
            return this;
        }
        return new AsciiString(value, start, end - start + 1, false);
    }

    
Compares a CharSequence to this String to determine if their contents are equal. 
Params:
a – the character sequence to compare to.
Returns:
true if equal, otherwise false/**
     * Compares a {@code CharSequence} to this {@code String} to determine if their contents are equal.
     *
     * @param a the character sequence to compare to.
     * @return {@code true} if equal, otherwise {@code false}
     */
    public boolean contentEquals(CharSequence a) {
        if (a == null || a.length() != length()) {
            return false;
        }
        if (a.getClass() == AsciiString.class) {
            return equals(a);
        }

        for (int i = arrayOffset(), j = 0; j < a.length(); ++i, ++j) {
            if (b2c(value[i]) != a.charAt(j)) {
                return false;
            }
        }
        return true;
    }

    
Determines whether this string matches a given regular expression.
Params:
expr – the regular expression to be matched.
Throws:
PatternSyntaxException – if the syntax of the supplied regular expression is not valid.
NullPointerException – if expr is null.
Returns:
true if the expression matches, otherwise false./**
     * Determines whether this string matches a given regular expression.
     *
     * @param expr the regular expression to be matched.
     * @return {@code true} if the expression matches, otherwise {@code false}.
     * @throws PatternSyntaxException if the syntax of the supplied regular expression is not valid.
     * @throws NullPointerException if {@code expr} is {@code null}.
     */
    public boolean matches(String expr) {
        return Pattern.matches(expr, this);
    }

    
Splits this string using the supplied regular expression expr. The parameter max controls the behavior how many times the pattern is applied to the string. 
Params:
expr – the regular expression used to divide the string.
max – the number of entries in the resulting array.
Throws:
NullPointerException – if expr is null.
PatternSyntaxException – if the syntax of the supplied regular expression is not valid.
See Also:
Pattern.split(CharSequence, int)
Returns:
an array of Strings created by separating the string along matches of the regular expression./**
     * Splits this string using the supplied regular expression {@code expr}. The parameter {@code max} controls the
     * behavior how many times the pattern is applied to the string.
     *
     * @param expr the regular expression used to divide the string.
     * @param max the number of entries in the resulting array.
     * @return an array of Strings created by separating the string along matches of the regular expression.
     * @throws NullPointerException if {@code expr} is {@code null}.
     * @throws PatternSyntaxException if the syntax of the supplied regular expression is not valid.
     * @see Pattern#split(CharSequence, int)
     */
    public AsciiString[] split(String expr, int max) {
        return toAsciiStringArray(Pattern.compile(expr).split(this, max));
    }

    
Splits the specified String with the specified delimiter.. /**
     * Splits the specified {@link String} with the specified delimiter..
     */
    public AsciiString[] split(char delim) {
        final List<AsciiString> res = InternalThreadLocalMap.get().arrayList();

        int start = 0;
        final int length = length();
        for (int i = start; i < length; i++) {
            if (charAt(i) == delim) {
                if (start == i) {
                    res.add(EMPTY_STRING);
                } else {
                    res.add(new AsciiString(value, start + arrayOffset(), i - start, false));
                }
                start = i + 1;
            }
        }

        if (start == 0) { // If no delimiter was found in the value
            res.add(this);
        } else {
            if (start != length) {
                // Add the last element if it's not empty.
                res.add(new AsciiString(value, start + arrayOffset(), length - start, false));
            } else {
                // Truncate trailing empty elements.
                for (int i = res.size() - 1; i >= 0; i--) {
                    if (res.get(i).isEmpty()) {
                        res.remove(i);
                    } else {
                        break;
                    }
                }
            }
        }

        return res.toArray(new AsciiString[res.size()]);
    }

    
{@inheritDoc}

Provides a case-insensitive hash code for Ascii like byte strings.
/**
     * {@inheritDoc}
     * <p>
     * Provides a case-insensitive hash code for Ascii like byte strings.
     */
    @Override
    public int hashCode() {
        int h = hash;
        if (h == 0) {
            h = PlatformDependent.hashCodeAscii(value, offset, length);
            hash = h;
        }
        return h;
    }

    @Override
    public boolean equals(Object obj) {
        if (obj == null || obj.getClass() != AsciiString.class) {
            return false;
        }
        if (this == obj) {
            return true;
        }

        AsciiString other = (AsciiString) obj;
        return length() == other.length() &&
               hashCode() == other.hashCode() &&
               PlatformDependent.equals(array(), arrayOffset(), other.array(), other.arrayOffset(), length());
    }

    
Translates the entire byte string to a String. 
See Also:
toString(int)/**
     * Translates the entire byte string to a {@link String}.
     * @see #toString(int)
     */
    @Override
    public String toString() {
        String cache = string;
        if (cache == null) {
            cache = toString(0);
            string = cache;
        }
        return cache;
    }

    
Translates the entire byte string to a String using the charset encoding. 
See Also:
toString(int, int)/**
     * Translates the entire byte string to a {@link String} using the {@code charset} encoding.
     * @see #toString(int, int)
     */
    public String toString(int start) {
        return toString(start, length());
    }

    
Translates the [start, end) range of this byte string to a String. /**
     * Translates the [{@code start}, {@code end}) range of this byte string to a {@link String}.
     */
    public String toString(int start, int end) {
        int length = end - start;
        if (length == 0) {
            return "";
        }

        if (isOutOfBounds(start, length, length())) {
            throw new IndexOutOfBoundsException("expected: " + "0 <= start(" + start + ") <= srcIdx + length("
                            + length + ") <= srcLen(" + length() + ')');
        }

        @SuppressWarnings("deprecation")
        final String str = new String(value, 0, start + offset, length);
        return str;
    }

    public boolean parseBoolean() {
        return length >= 1 && value[offset] != 0;
    }

    public char parseChar() {
        return parseChar(0);
    }

    public char parseChar(int start) {
        if (start + 1 >= length()) {
            throw new IndexOutOfBoundsException("2 bytes required to convert to character. index " +
                    start + " would go out of bounds.");
        }
        final int startWithOffset = start + offset;
        return (char) ((b2c(value[startWithOffset]) << 8) | b2c(value[startWithOffset + 1]));
    }

    public short parseShort() {
        return parseShort(0, length(), 10);
    }

    public short parseShort(int radix) {
        return parseShort(0, length(), radix);
    }

    public short parseShort(int start, int end) {
        return parseShort(start, end, 10);
    }

    public short parseShort(int start, int end, int radix) {
        int intValue = parseInt(start, end, radix);
        short result = (short) intValue;
        if (result != intValue) {
            throw new NumberFormatException(subSequence(start, end, false).toString());
        }
        return result;
    }

    public int parseInt() {
        return parseInt(0, length(), 10);
    }

    public int parseInt(int radix) {
        return parseInt(0, length(), radix);
    }

    public int parseInt(int start, int end) {
        return parseInt(start, end, 10);
    }

    public int parseInt(int start, int end, int radix) {
        if (radix < Character.MIN_RADIX || radix > Character.MAX_RADIX) {
            throw new NumberFormatException();
        }

        if (start == end) {
            throw new NumberFormatException();
        }

        int i = start;
        boolean negative = byteAt(i) == '-';
        if (negative && ++i == end) {
            throw new NumberFormatException(subSequence(start, end, false).toString());
        }

        return parseInt(i, end, radix, negative);
    }

    private int parseInt(int start, int end, int radix, boolean negative) {
        int max = Integer.MIN_VALUE / radix;
        int result = 0;
        int currOffset = start;
        while (currOffset < end) {
            int digit = Character.digit((char) (value[currOffset++ + offset] & 0xFF), radix);
            if (digit == -1) {
                throw new NumberFormatException(subSequence(start, end, false).toString());
            }
            if (max > result) {
                throw new NumberFormatException(subSequence(start, end, false).toString());
            }
            int next = result * radix - digit;
            if (next > result) {
                throw new NumberFormatException(subSequence(start, end, false).toString());
            }
            result = next;
        }
        if (!negative) {
            result = -result;
            if (result < 0) {
                throw new NumberFormatException(subSequence(start, end, false).toString());
            }
        }
        return result;
    }

    public long parseLong() {
        return parseLong(0, length(), 10);
    }

    public long parseLong(int radix) {
        return parseLong(0, length(), radix);
    }

    public long parseLong(int start, int end) {
        return parseLong(start, end, 10);
    }

    public long parseLong(int start, int end, int radix) {
        if (radix < Character.MIN_RADIX || radix > Character.MAX_RADIX) {
            throw new NumberFormatException();
        }

        if (start == end) {
            throw new NumberFormatException();
        }

        int i = start;
        boolean negative = byteAt(i) == '-';
        if (negative && ++i == end) {
            throw new NumberFormatException(subSequence(start, end, false).toString());
        }

        return parseLong(i, end, radix, negative);
    }

    private long parseLong(int start, int end, int radix, boolean negative) {
        long max = Long.MIN_VALUE / radix;
        long result = 0;
        int currOffset = start;
        while (currOffset < end) {
            int digit = Character.digit((char) (value[currOffset++ + offset] & 0xFF), radix);
            if (digit == -1) {
                throw new NumberFormatException(subSequence(start, end, false).toString());
            }
            if (max > result) {
                throw new NumberFormatException(subSequence(start, end, false).toString());
            }
            long next = result * radix - digit;
            if (next > result) {
                throw new NumberFormatException(subSequence(start, end, false).toString());
            }
            result = next;
        }
        if (!negative) {
            result = -result;
            if (result < 0) {
                throw new NumberFormatException(subSequence(start, end, false).toString());
            }
        }
        return result;
    }

    public float parseFloat() {
        return parseFloat(0, length());
    }

    public float parseFloat(int start, int end) {
        return Float.parseFloat(toString(start, end));
    }

    public double parseDouble() {
        return parseDouble(0, length());
    }

    public double parseDouble(int start, int end) {
        return Double.parseDouble(toString(start, end));
    }

    public static final HashingStrategy<CharSequence> CASE_INSENSITIVE_HASHER =
            new HashingStrategy<CharSequence>() {
        @Override
        public int hashCode(CharSequence o) {
            return AsciiString.hashCode(o);
        }

        @Override
        public boolean equals(CharSequence a, CharSequence b) {
            return AsciiString.contentEqualsIgnoreCase(a, b);
        }
    };

    public static final HashingStrategy<CharSequence> CASE_SENSITIVE_HASHER =
            new HashingStrategy<CharSequence>() {
        @Override
        public int hashCode(CharSequence o) {
            return AsciiString.hashCode(o);
        }

        @Override
        public boolean equals(CharSequence a, CharSequence b) {
            return AsciiString.contentEquals(a, b);
        }
    };

    
Returns an AsciiString containing the given character sequence. If the given string is already a AsciiString, just returns the same instance. /**
     * Returns an {@link AsciiString} containing the given character sequence. If the given string is already a
     * {@link AsciiString}, just returns the same instance.
     */
    public static AsciiString of(CharSequence string) {
        return string.getClass() == AsciiString.class ? (AsciiString) string : new AsciiString(string);
    }

    
Returns an AsciiString containing the given string and retains/caches the input string for later use in toString(). Used for the constants (which already stored in the JVM's string table) and in cases where the guaranteed use of the toString() method. /**
     * Returns an {@link AsciiString} containing the given string and retains/caches the input
     * string for later use in {@link #toString()}.
     * Used for the constants (which already stored in the JVM's string table) and in cases
     * where the guaranteed use of the {@link #toString()} method.
     */
    public static AsciiString cached(String string) {
        AsciiString asciiString = new AsciiString(string);
        asciiString.string = string;
        return asciiString;
    }

    
Returns the case-insensitive hash code of the specified string. Note that this method uses the same hashing algorithm with hashCode() so that you can put both AsciiStrings and arbitrary CharSequences into the same headers. /**
     * Returns the case-insensitive hash code of the specified string. Note that this method uses the same hashing
     * algorithm with {@link #hashCode()} so that you can put both {@link AsciiString}s and arbitrary
     * {@link CharSequence}s into the same headers.
     */
    public static int hashCode(CharSequence value) {
        if (value == null) {
            return 0;
        }
        if (value.getClass() == AsciiString.class) {
            return value.hashCode();
        }

        return PlatformDependent.hashCodeAscii(value);
    }

    
Determine if a contains b in a case sensitive manner. /**
     * Determine if {@code a} contains {@code b} in a case sensitive manner.
     */
    public static boolean contains(CharSequence a, CharSequence b) {
        return contains(a, b, DefaultCharEqualityComparator.INSTANCE);
    }

    
Determine if a contains b in a case insensitive manner. /**
     * Determine if {@code a} contains {@code b} in a case insensitive manner.
     */
    public static boolean containsIgnoreCase(CharSequence a, CharSequence b) {
        return contains(a, b, AsciiCaseInsensitiveCharEqualityComparator.INSTANCE);
    }

    
Returns true if both CharSequence's are equals when ignore the case. This only supports 8-bit ASCII. /**
     * Returns {@code true} if both {@link CharSequence}'s are equals when ignore the case. This only supports 8-bit
     * ASCII.
     */
    public static boolean contentEqualsIgnoreCase(CharSequence a, CharSequence b) {
        if (a == null || b == null) {
            return a == b;
        }

        if (a.getClass() == AsciiString.class) {
            return ((AsciiString) a).contentEqualsIgnoreCase(b);
        }
        if (b.getClass() == AsciiString.class) {
            return ((AsciiString) b).contentEqualsIgnoreCase(a);
        }

        if (a.length() != b.length()) {
            return false;
        }
        for (int i = 0, j = 0; i < a.length(); ++i, ++j) {
            if (!equalsIgnoreCase(a.charAt(i),  b.charAt(j))) {
                return false;
            }
        }
        return true;
    }

    
Determine if collection contains value and using contentEqualsIgnoreCase(CharSequence, CharSequence) to compare values. 
Params:
collection – The collection to look for and equivalent element as value.
value – The value to look for in collection.
See Also:
contentEqualsIgnoreCase(CharSequence, CharSequence)
Returns:
true if collection contains value according to contentEqualsIgnoreCase(CharSequence, CharSequence). false otherwise./**
     * Determine if {@code collection} contains {@code value} and using
     * {@link #contentEqualsIgnoreCase(CharSequence, CharSequence)} to compare values.
     * @param collection The collection to look for and equivalent element as {@code value}.
     * @param value The value to look for in {@code collection}.
     * @return {@code true} if {@code collection} contains {@code value} according to
     * {@link #contentEqualsIgnoreCase(CharSequence, CharSequence)}. {@code false} otherwise.
     * @see #contentEqualsIgnoreCase(CharSequence, CharSequence)
     */
    public static boolean containsContentEqualsIgnoreCase(Collection<CharSequence> collection, CharSequence value) {
        for (CharSequence v : collection) {
            if (contentEqualsIgnoreCase(value, v)) {
                return true;
            }
        }
        return false;
    }

    
Determine if a contains all of the values in b using contentEqualsIgnoreCase(CharSequence, CharSequence) to compare values. 
Params:
a – The collection under test.
b – The values to test for.
See Also:
contentEqualsIgnoreCase(CharSequence, CharSequence)
Returns:
true if a contains all of the values in b using contentEqualsIgnoreCase(CharSequence, CharSequence) to compare values. false otherwise./**
     * Determine if {@code a} contains all of the values in {@code b} using
     * {@link #contentEqualsIgnoreCase(CharSequence, CharSequence)} to compare values.
     * @param a The collection under test.
     * @param b The values to test for.
     * @return {@code true} if {@code a} contains all of the values in {@code b} using
     * {@link #contentEqualsIgnoreCase(CharSequence, CharSequence)} to compare values. {@code false} otherwise.
     * @see #contentEqualsIgnoreCase(CharSequence, CharSequence)
     */
    public static boolean containsAllContentEqualsIgnoreCase(Collection<CharSequence> a, Collection<CharSequence> b) {
        for (CharSequence v : b) {
            if (!containsContentEqualsIgnoreCase(a, v)) {
                return false;
            }
        }
        return true;
    }

    
Returns true if the content of both CharSequence's are equals. This only supports 8-bit ASCII. /**
     * Returns {@code true} if the content of both {@link CharSequence}'s are equals. This only supports 8-bit ASCII.
     */
    public static boolean contentEquals(CharSequence a, CharSequence b) {
        if (a == null || b == null) {
            return a == b;
        }

        if (a.getClass() == AsciiString.class) {
            return ((AsciiString) a).contentEquals(b);
        }

        if (b.getClass() == AsciiString.class) {
            return ((AsciiString) b).contentEquals(a);
        }

        if (a.length() != b.length()) {
            return false;
        }
        for (int i = 0; i <  a.length(); ++i) {
            if (a.charAt(i) != b.charAt(i)) {
                return false;
            }
        }
        return true;
    }

    private static AsciiString[] toAsciiStringArray(String[] jdkResult) {
        AsciiString[] res = new AsciiString[jdkResult.length];
        for (int i = 0; i < jdkResult.length; i++) {
            res[i] = new AsciiString(jdkResult[i]);
        }
        return res;
    }

    private interface CharEqualityComparator {
        boolean equals(char a, char b);
    }

    private static final class DefaultCharEqualityComparator implements CharEqualityComparator {
        static final DefaultCharEqualityComparator INSTANCE = new DefaultCharEqualityComparator();
        private DefaultCharEqualityComparator() { }

        @Override
        public boolean equals(char a, char b) {
            return a == b;
        }
    }

    private static final class AsciiCaseInsensitiveCharEqualityComparator implements CharEqualityComparator {
        static final AsciiCaseInsensitiveCharEqualityComparator
                INSTANCE = new AsciiCaseInsensitiveCharEqualityComparator();
        private AsciiCaseInsensitiveCharEqualityComparator() { }

        @Override
        public boolean equals(char a, char b) {
            return equalsIgnoreCase(a, b);
        }
    }

    private static final class GeneralCaseInsensitiveCharEqualityComparator implements CharEqualityComparator {
        static final GeneralCaseInsensitiveCharEqualityComparator
                INSTANCE = new GeneralCaseInsensitiveCharEqualityComparator();
        private GeneralCaseInsensitiveCharEqualityComparator() { }

        @Override
        public boolean equals(char a, char b) {
            //For motivation, why we need two checks, see comment in String#regionMatches
            return Character.toUpperCase(a) == Character.toUpperCase(b) ||
                Character.toLowerCase(a) == Character.toLowerCase(b);
        }
    }

    private static boolean contains(CharSequence a, CharSequence b, CharEqualityComparator cmp) {
        if (a == null || b == null || a.length() < b.length()) {
            return false;
        }
        if (b.length() == 0) {
            return true;
        }
        int bStart = 0;
        for (int i = 0; i < a.length(); ++i) {
            if (cmp.equals(b.charAt(bStart), a.charAt(i))) {
                // If b is consumed then true.
                if (++bStart == b.length()) {
                    return true;
                }
            } else if (a.length() - i < b.length()) {
                // If there are not enough characters left in a for b to be contained, then false.
                return false;
            } else {
                bStart = 0;
            }
        }
        return false;
    }

    private static boolean regionMatchesCharSequences(final CharSequence cs, final int csStart,
                                         final CharSequence string, final int start, final int length,
                                         CharEqualityComparator charEqualityComparator) {
        //general purpose implementation for CharSequences
        if (csStart < 0 || length > cs.length() - csStart) {
            return false;
        }
        if (start < 0 || length > string.length() - start) {
            return false;
        }

        int csIndex = csStart;
        int csEnd = csIndex + length;
        int stringIndex = start;

        while (csIndex < csEnd) {
            char c1 = cs.charAt(csIndex++);
            char c2 = string.charAt(stringIndex++);

            if (!charEqualityComparator.equals(c1, c2)) {
                return false;
            }
        }
        return true;
    }

    
This methods make regionMatches operation correctly for any chars in strings
Params:
cs – the CharSequence to be processed
ignoreCase – specifies if case should be ignored.
csStart – the starting offset in the cs CharSequence
string – the CharSequence to compare.
start – the starting offset in the specified string.
length – the number of characters to compare.
Returns:
true if the ranges of characters are equal, false otherwise./**
     * This methods make regionMatches operation correctly for any chars in strings
     * @param cs the {@code CharSequence} to be processed
     * @param ignoreCase specifies if case should be ignored.
     * @param csStart the starting offset in the {@code cs} CharSequence
     * @param string the {@code CharSequence} to compare.
     * @param start the starting offset in the specified {@code string}.
     * @param length the number of characters to compare.
     * @return {@code true} if the ranges of characters are equal, {@code false} otherwise.
     */
    public static boolean regionMatches(final CharSequence cs, final boolean ignoreCase, final int csStart,
                                        final CharSequence string, final int start, final int length) {
        if (cs == null || string == null) {
            return false;
        }

        if (cs instanceof String && string instanceof String) {
            return ((String) cs).regionMatches(ignoreCase, csStart, (String) string, start, length);
        }

        if (cs instanceof AsciiString) {
            return ((AsciiString) cs).regionMatches(ignoreCase, csStart, string, start, length);
        }

        return regionMatchesCharSequences(cs, csStart, string, start, length,
                                            ignoreCase ? GeneralCaseInsensitiveCharEqualityComparator.INSTANCE :
                                                    DefaultCharEqualityComparator.INSTANCE);
    }

    
This is optimized version of regionMatches for string with ASCII chars only
Params:
cs – the CharSequence to be processed
ignoreCase – specifies if case should be ignored.
csStart – the starting offset in the cs CharSequence
string – the CharSequence to compare.
start – the starting offset in the specified string.
length – the number of characters to compare.
Returns:
true if the ranges of characters are equal, false otherwise./**
     * This is optimized version of regionMatches for string with ASCII chars only
     * @param cs the {@code CharSequence} to be processed
     * @param ignoreCase specifies if case should be ignored.
     * @param csStart the starting offset in the {@code cs} CharSequence
     * @param string the {@code CharSequence} to compare.
     * @param start the starting offset in the specified {@code string}.
     * @param length the number of characters to compare.
     * @return {@code true} if the ranges of characters are equal, {@code false} otherwise.
     */
    public static boolean regionMatchesAscii(final CharSequence cs, final boolean ignoreCase, final int csStart,
                                        final CharSequence string, final int start, final int length) {
        if (cs == null || string == null) {
            return false;
        }

        if (!ignoreCase && cs instanceof String && string instanceof String) {
            //we don't call regionMatches from String for ignoreCase==true. It's a general purpose method,
            //which make complex comparison in case of ignoreCase==true, which is useless for ASCII-only strings.
            //To avoid applying this complex ignore-case comparison, we will use regionMatchesCharSequences
            return ((String) cs).regionMatches(false, csStart, (String) string, start, length);
        }

        if (cs instanceof AsciiString) {
            return ((AsciiString) cs).regionMatches(ignoreCase, csStart, string, start, length);
        }

        return regionMatchesCharSequences(cs, csStart, string, start, length,
                                          ignoreCase ? AsciiCaseInsensitiveCharEqualityComparator.INSTANCE :
                                                      DefaultCharEqualityComparator.INSTANCE);
    }

    
Case in-sensitive find of the first index within a CharSequence
from the specified position.
A null CharSequence will return -1. A negative start position is treated as zero. An empty ("") search CharSequence always matches. A start position greater than the string length only matches an empty search CharSequence.
AsciiString.indexOfIgnoreCase(null, *, *)          = -1
AsciiString.indexOfIgnoreCase(*, null, *)          = -1
AsciiString.indexOfIgnoreCase("", "", 0)           = 0
AsciiString.indexOfIgnoreCase("aabaabaa", "A", 0)  = 0
AsciiString.indexOfIgnoreCase("aabaabaa", "B", 0)  = 2
AsciiString.indexOfIgnoreCase("aabaabaa", "AB", 0) = 1
AsciiString.indexOfIgnoreCase("aabaabaa", "B", 3)  = 5
AsciiString.indexOfIgnoreCase("aabaabaa", "B", 9)  = -1
AsciiString.indexOfIgnoreCase("aabaabaa", "B", -1) = 2
AsciiString.indexOfIgnoreCase("aabaabaa", "", 2)   = 2
AsciiString.indexOfIgnoreCase("abc", "", 9)        = -1

Params:
str –  the CharSequence to check, may be null
searchStr –  the CharSequence to find, may be null
startPos –  the start position, negative treated as zero
Returns:
the first index of the search CharSequence (always ≥ startPos), -1 if no match or null string input/**
     * <p>Case in-sensitive find of the first index within a CharSequence
     * from the specified position.</p>
     *
     * <p>A {@code null} CharSequence will return {@code -1}.
     * A negative start position is treated as zero.
     * An empty ("") search CharSequence always matches.
     * A start position greater than the string length only matches
     * an empty search CharSequence.</p>
     *
     * <pre>
     * AsciiString.indexOfIgnoreCase(null, *, *)          = -1
     * AsciiString.indexOfIgnoreCase(*, null, *)          = -1
     * AsciiString.indexOfIgnoreCase("", "", 0)           = 0
     * AsciiString.indexOfIgnoreCase("aabaabaa", "A", 0)  = 0
     * AsciiString.indexOfIgnoreCase("aabaabaa", "B", 0)  = 2
     * AsciiString.indexOfIgnoreCase("aabaabaa", "AB", 0) = 1
     * AsciiString.indexOfIgnoreCase("aabaabaa", "B", 3)  = 5
     * AsciiString.indexOfIgnoreCase("aabaabaa", "B", 9)  = -1
     * AsciiString.indexOfIgnoreCase("aabaabaa", "B", -1) = 2
     * AsciiString.indexOfIgnoreCase("aabaabaa", "", 2)   = 2
     * AsciiString.indexOfIgnoreCase("abc", "", 9)        = -1
     * </pre>
     *
     * @param str  the CharSequence to check, may be null
     * @param searchStr  the CharSequence to find, may be null
     * @param startPos  the start position, negative treated as zero
     * @return the first index of the search CharSequence (always &ge; startPos),
     *  -1 if no match or {@code null} string input
     */
    public static int indexOfIgnoreCase(final CharSequence str, final CharSequence searchStr, int startPos) {
        if (str == null || searchStr == null) {
            return INDEX_NOT_FOUND;
        }
        if (startPos < 0) {
            startPos = 0;
        }
        int searchStrLen = searchStr.length();
        final int endLimit = str.length() - searchStrLen + 1;
        if (startPos > endLimit) {
            return INDEX_NOT_FOUND;
        }
        if (searchStrLen == 0) {
            return startPos;
        }
        for (int i = startPos; i < endLimit; i++) {
            if (regionMatches(str, true, i, searchStr, 0, searchStrLen)) {
                return i;
            }
        }
        return INDEX_NOT_FOUND;
    }

    
Case in-sensitive find of the first index within a CharSequence
from the specified position. This method optimized and works correctly for ASCII CharSequences only
A null CharSequence will return -1. A negative start position is treated as zero. An empty ("") search CharSequence always matches. A start position greater than the string length only matches an empty search CharSequence.
AsciiString.indexOfIgnoreCase(null, *, *)          = -1
AsciiString.indexOfIgnoreCase(*, null, *)          = -1
AsciiString.indexOfIgnoreCase("", "", 0)           = 0
AsciiString.indexOfIgnoreCase("aabaabaa", "A", 0)  = 0
AsciiString.indexOfIgnoreCase("aabaabaa", "B", 0)  = 2
AsciiString.indexOfIgnoreCase("aabaabaa", "AB", 0) = 1
AsciiString.indexOfIgnoreCase("aabaabaa", "B", 3)  = 5
AsciiString.indexOfIgnoreCase("aabaabaa", "B", 9)  = -1
AsciiString.indexOfIgnoreCase("aabaabaa", "B", -1) = 2
AsciiString.indexOfIgnoreCase("aabaabaa", "", 2)   = 2
AsciiString.indexOfIgnoreCase("abc", "", 9)        = -1

Params:
str –  the CharSequence to check, may be null
searchStr –  the CharSequence to find, may be null
startPos –  the start position, negative treated as zero
Returns:
the first index of the search CharSequence (always ≥ startPos), -1 if no match or null string input/**
     * <p>Case in-sensitive find of the first index within a CharSequence
     * from the specified position. This method optimized and works correctly for ASCII CharSequences only</p>
     *
     * <p>A {@code null} CharSequence will return {@code -1}.
     * A negative start position is treated as zero.
     * An empty ("") search CharSequence always matches.
     * A start position greater than the string length only matches
     * an empty search CharSequence.</p>
     *
     * <pre>
     * AsciiString.indexOfIgnoreCase(null, *, *)          = -1
     * AsciiString.indexOfIgnoreCase(*, null, *)          = -1
     * AsciiString.indexOfIgnoreCase("", "", 0)           = 0
     * AsciiString.indexOfIgnoreCase("aabaabaa", "A", 0)  = 0
     * AsciiString.indexOfIgnoreCase("aabaabaa", "B", 0)  = 2
     * AsciiString.indexOfIgnoreCase("aabaabaa", "AB", 0) = 1
     * AsciiString.indexOfIgnoreCase("aabaabaa", "B", 3)  = 5
     * AsciiString.indexOfIgnoreCase("aabaabaa", "B", 9)  = -1
     * AsciiString.indexOfIgnoreCase("aabaabaa", "B", -1) = 2
     * AsciiString.indexOfIgnoreCase("aabaabaa", "", 2)   = 2
     * AsciiString.indexOfIgnoreCase("abc", "", 9)        = -1
     * </pre>
     *
     * @param str  the CharSequence to check, may be null
     * @param searchStr  the CharSequence to find, may be null
     * @param startPos  the start position, negative treated as zero
     * @return the first index of the search CharSequence (always &ge; startPos),
     *  -1 if no match or {@code null} string input
     */
    public static int indexOfIgnoreCaseAscii(final CharSequence str, final CharSequence searchStr, int startPos) {
        if (str == null || searchStr == null) {
            return INDEX_NOT_FOUND;
        }
        if (startPos < 0) {
            startPos = 0;
        }
        int searchStrLen = searchStr.length();
        final int endLimit = str.length() - searchStrLen + 1;
        if (startPos > endLimit) {
            return INDEX_NOT_FOUND;
        }
        if (searchStrLen == 0) {
            return startPos;
        }
        for (int i = startPos; i < endLimit; i++) {
            if (regionMatchesAscii(str, true, i, searchStr, 0, searchStrLen)) {
                return i;
            }
        }
        return INDEX_NOT_FOUND;
    }

    
Finds the first index in the CharSequence that matches the specified character.
Params:
cs –  the CharSequence to be processed, not null
searchChar – the char to be searched for
start –  the start index, negative starts at the string start
Returns:
the index where the search char was found, -1 if char searchChar is not found or cs == null/**
     * <p>Finds the first index in the {@code CharSequence} that matches the
     * specified character.</p>
     *
     * @param cs  the {@code CharSequence} to be processed, not null
     * @param searchChar the char to be searched for
     * @param start  the start index, negative starts at the string start
     * @return the index where the search char was found,
     * -1 if char {@code searchChar} is not found or {@code cs == null}
     */
    //-----------------------------------------------------------------------
    public static int indexOf(final CharSequence cs, final char searchChar, int start) {
        if (cs instanceof String) {
            return ((String) cs).indexOf(searchChar, start);
        } else if (cs instanceof AsciiString) {
            return ((AsciiString) cs).indexOf(searchChar, start);
        }
        if (cs == null) {
            return INDEX_NOT_FOUND;
        }
        final int sz = cs.length();
        for (int i = start < 0 ? 0 : start; i < sz; i++) {
            if (cs.charAt(i) == searchChar) {
                return i;
            }
        }
        return INDEX_NOT_FOUND;
    }

    private static boolean equalsIgnoreCase(byte a, byte b) {
        return a == b || toLowerCase(a) == toLowerCase(b);
    }

    private static boolean equalsIgnoreCase(char a, char b) {
        return a == b || toLowerCase(a) == toLowerCase(b);
    }

    private static byte toLowerCase(byte b) {
        return isUpperCase(b) ? (byte) (b + 32) : b;
    }

    private static char toLowerCase(char c) {
        return isUpperCase(c) ? (char) (c + 32) : c;
    }

    private static byte toUpperCase(byte b) {
        return isLowerCase(b) ? (byte) (b - 32) : b;
    }

    private static boolean isLowerCase(byte value) {
        return value >= 'a' && value <= 'z';
    }

    public static boolean isUpperCase(byte value) {
        return value >= 'A' && value <= 'Z';
    }

    public static boolean isUpperCase(char value) {
        return value >= 'A' && value <= 'Z';
    }

    public static byte c2b(char c) {
        return (byte) ((c > MAX_CHAR_VALUE) ? '?' : c);
    }

    private static byte c2b0(char c) {
        return (byte) c;
    }

    public static char b2c(byte b) {
        return (char) (b & 0xFF);
    }
}