/*
 
* Copyright (c) 2003, 2013, Oracle and/or its affiliates. All rights reserved.
 
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 
*
 
* This code is free software; you can redistribute it and/or modify it
 
* under the terms of the GNU General Public License version 2 only, as
 
* published by the Free Software Foundation.
  
Oracle designates this
 
* particular file as subject to the "Classpath" exception as provided
 
* by Oracle in the LICENSE file that accompanied this code.
 
*
 
* This code is distributed in the hope that it will be useful, but WITHOUT
 
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 
* FITNESS FOR A PARTICULAR PURPOSE.
  
See the GNU General Public License
 
* version 2 for more details (a copy is included in the LICENSE file that
 
* accompanied this code).
 
*
 
* You should have received a copy of the GNU General Public License version
 
* 2 along with this work; if not, write to the Free Software Foundation,
 
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 
*
 
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 
* or visit www.oracle.com if you need additional information or have any
 
* questions.
 
*/

package java.util;

import java.nio.file.Path;
import java.nio.file.Files;
import java.util.regex.*;
import java.io.*;
import java.math.*;
import java.nio.*;
import java.nio.channels.*;
import java.nio.charset.*;
import java.text.*;
import java.util.Locale;

import sun.misc.LRUCache;

/**
 
* A simple text scanner which can parse primitive types and strings using
 
* regular expressions.
 
*
 
* <p>A <code>Scanner</code> breaks its input into tokens using a
 
* delimiter pattern, which by default matches whitespace. The resulting
 
* tokens may then be converted into values of different types using the
 
* various <tt>next</tt> methods.
 
*
 
* <p>For example, this code allows a user to read a number from
 
* <tt>System.in</tt>:
 
* <blockquote><pre>{@code
 
*
     
Scanner sc = new Scanner(System.in);
 
*
     
int i = sc.nextInt();
 
* }</pre></blockquote>
 
*
 
* <p>As another example, this code allows <code>long</code> types to be
 
* assigned from entries in a file <code>myNumbers</code>:
 
* <blockquote><pre>{@code
 
*
      
Scanner sc = new Scanner(new File("myNumbers"));
 
*
      
while (sc.hasNextLong()) {
 
*
          
long aLong = sc.nextLong();
 
*
      
}
 
* }</pre></blockquote>
 
*
 
* <p>The scanner can also use delimiters other than whitespace. This
 
* example reads several items in from a string:
 
* <blockquote><pre>{@code
 
*
     
String input = "1 fish 2 fish red fish blue fish";
 
*
     
Scanner s = new Scanner(input).useDelimiter("\\s*fish\\s*");
 
*
     
System.out.println(s.nextInt());
 
*
     
System.out.println(s.nextInt());
 
*
     
System.out.println(s.next());
 
*
     
System.out.println(s.next());
 
*
     
s.close();
 
* }</pre></blockquote>
 
* <p>
 
* prints the following output:
 
* <blockquote><pre>{@code
 
*
     
1
 
*
     
2
 
*
     
red
 
*
     
blue
 
* }</pre></blockquote>
 
*
 
* <p>The same output can be generated with this code, which uses a regular
 
* expression to parse all four tokens at once:
 
* <blockquote><pre>{@code
 
*
     
String input = "1 fish 2 fish red fish blue fish";
 
*
     
Scanner s = new Scanner(input);
 
*
     
s.findInLine("(\\d+) fish (\\d+) fish (\\w+) fish (\\w+)");
 
*
     
MatchResult result = s.match();
 
*
     
for (int i=1; i<=result.groupCount(); i++)
 
*
         
System.out.println(result.group(i));
 
*
     
s.close();
 
* }</pre></blockquote>
 
*
 
* <p>The <a name="default-delimiter">default whitespace delimiter</a> used
 
* by a scanner is as recognized by .{@link
 
* java.lang.Character#isWhitespace(char) isWhitespace}. The {@link #reset}
 
* method will reset the value of the scanner's delimiter to the default
 
* whitespace delimiter regardless of whether it was previously changed.
 
*
 
* <p>A scanning operation may block waiting for input.
 
*
 
* <p>The {@link #next} and {@link #hasNext} methods and their
 
* primitive-type companion methods (such as {@link #nextInt} and
 
* {@link #hasNextInt}) first skip any input that matches the delimiter
 
* pattern, and then attempt to return the next token. Both <tt>hasNext</tt>
 
* and <tt>next</tt> methods may block waiting for further input.
  
Whether a
 
* <tt>hasNext</tt> method blocks has no connection to whether or not its
 
* associated <tt>next</tt> method will block.
 
*
 
* <p> The {@link #findInLine}, {@link #findWithinHorizon}, and {@link #skip}
 
* methods operate independently of the delimiter pattern. These methods will
 
* attempt to match the specified pattern with no regard to delimiters in the
 
* input and thus can be used in special circumstances where delimiters are
 
* not relevant. These methods may block waiting for more input.
 
*
 
* <p>When a scanner throws an {@link InputMismatchException}, the scanner
 
* will not pass the token that caused the exception, so that it may be
 
* retrieved or skipped via some other method.
 
*
 
* <p>Depending upon the type of delimiting pattern, empty tokens may be
 
* returned. For example, the pattern <tt>"\\s+"</tt> will return no empty
 
* tokens since it matches multiple instances of the delimiter. The delimiting
 
* pattern <tt>"\\s"</tt> could return empty tokens since it only passes one
 
* space at a time.
 
*
 
* <p> A scanner can read text from any object which implements the {@link
 
* java.lang.Readable} interface.
  
If an invocation of the underlying
 
* readable's {@link java.lang.Readable#read} method throws an {@link
 
* java.io.IOException} then the scanner assumes that the end of the input
 
* has been reached.
  
The most recent <tt>IOException</tt> thrown by the
 
* underlying readable can be retrieved via the {@link #ioException} method.
 
*
 
* <p>When a <code>Scanner</code> is closed, it will close its input source
 
* if the source implements the
 
interface.
 
*
 
* <p>A <code>Scanner</code> is not safe for multithreaded use without
 
* external synchronization.
 
*
 
* <p>Unless otherwise mentioned, passing a <code>null</code> parameter into
 
* any method of a <code>Scanner</code> will cause a
 
* <code>NullPointerException</code> to be thrown.
 
*
 
* <p>A scanner will default to interpreting numbers as decimal unless a
 
* different radix has been set by using the {@link #useRadix} method. The
 
* {@link #reset} method will reset the value of the scanner's radix to
 
* <code>10</code> regardless of whether it was previously changed.
 
*
 
* <h3> <a name="localized-numbers">Localized numbers</a> </h3>
 
*
 
* <p> An instance of this class is capable of scanning numbers in the standard
 
* formats as well as in the formats of the scanner's locale. A scanner's
 
* <a name="initial-locale">initial locale </a>is the value returned by the {@link
 
* java.util.Locale#getDefault(Locale.Category)
 
* Locale.getDefault(Locale.Category.FORMAT)} method; it may be changed via the {@link
 
* #useLocale} method. The {@link #reset} method will reset the value of the
 
* scanner's locale to the initial locale regardless of whether it was
 
* previously changed.
 
*
 
* <p>The localized formats are defined in terms of the following parameters,
 
* which for a particular locale are taken from that locale's {@link
 
* java.text.DecimalFormat DecimalFormat} object, <tt>df</tt>, and its and
 
* {@link java.text.DecimalFormatSymbols DecimalFormatSymbols} object,
 
* <tt>dfs</tt>.
 
*
 
* <blockquote><dl>
 
*
     
<dt><i>LocalGroupSeparator&nbsp;&nbsp;</i>
 
*
         
<dd>The character used to separate thousands groups,
 
*
         
<i>i.e.,</i>&nbsp;<tt>dfs.</tt>{@link
 
*
         
java.text.DecimalFormatSymbols#getGroupingSeparator
 
*
         
getGroupingSeparator()}
 
*
     
<dt><i>LocalDecimalSeparator&nbsp;&nbsp;</i>
 
*
         
<dd>The character used for the decimal point,
 
*
     
<i>i.e.,</i>&nbsp;<tt>dfs.</tt>{@link
 
*
     
java.text.DecimalFormatSymbols#getDecimalSeparator
 
*
     
getDecimalSeparator()}
 
*
     
<dt><i>LocalPositivePrefix&nbsp;&nbsp;</i>
 
*
         
<dd>The string that appears before a positive number (may
 
*
         
be empty), <i>i.e.,</i>&nbsp;<tt>df.</tt>{@link
 
*
         
java.text.DecimalFormat#getPositivePrefix
 
*
         
getPositivePrefix()}
 
*
     
<dt><i>LocalPositiveSuffix&nbsp;&nbsp;</i>
 
*
         
<dd>The string that appears after a positive number (may be
 
*
         
empty), <i>i.e.,</i>&nbsp;<tt>df.</tt>{@link
 
*
         
java.text.DecimalFormat#getPositiveSuffix
 
*
         
getPositiveSuffix()}
 
*
     
<dt><i>LocalNegativePrefix&nbsp;&nbsp;</i>
 
*
         
<dd>The string that appears before a negative number (may
 
*
         
be empty), <i>i.e.,</i>&nbsp;<tt>df.</tt>{@link
 
*
         
java.text.DecimalFormat#getNegativePrefix
 
*
         
getNegativePrefix()}
 
*
     
<dt><i>LocalNegativeSuffix&nbsp;&nbsp;</i>
 
*
         
<dd>The string that appears after a negative number (may be
 
*
         
empty), <i>i.e.,</i>&nbsp;<tt>df.</tt>{@link
 
*
     
java.text.DecimalFormat#getNegativeSuffix
 
*
     
getNegativeSuffix()}
 
*
     
<dt><i>LocalNaN&nbsp;&nbsp;</i>
 
*
         
<dd>The string that represents not-a-number for
 
*
         
floating-point values,
 
*
         
<i>i.e.,</i>&nbsp;<tt>dfs.</tt>{@link
 
*
         
java.text.DecimalFormatSymbols#getNaN
 
*
         
getNaN()}
 
*
     
<dt><i>LocalInfinity&nbsp;&nbsp;</i>
 
*
         
<dd>The string that represents infinity for floating-point
 
*
         
values, <i>i.e.,</i>&nbsp;<tt>dfs.</tt>{@link
 
*
         
java.text.DecimalFormatSymbols#getInfinity
 
*
         
getInfinity()}
 
* </dl></blockquote>
 
*
 
* <h4> <a name="number-syntax">Number syntax</a> </h4>
 
*
 
* <p> The strings that can be parsed as numbers by an instance of this class
 
* are specified in terms of the following regular-expression grammar, where
 
* Rmax is the highest digit in the radix being used (for example, Rmax is 9 in base 10).
 
*
 
* <dl>
 
*
   
<dt><i>NonAsciiDigit</i>:
 
*
       
<dd>A non-ASCII character c for which
 
*
            
{@link java.lang.Character#isDigit Character.isDigit}<tt>(c)</tt>
 
*
                        
returns&nbsp;true
 
*
 
*
   
<dt><i>Non0Digit</i>:
 
*
       
<dd><tt>[1-</tt><i>Rmax</i><tt>] | </tt><i>NonASCIIDigit</i>
 
*
 
*
   
<dt><i>Digit</i>:
 
*
       
<dd><tt>[0-</tt><i>Rmax</i><tt>] | </tt><i>NonASCIIDigit</i>
 
*
 
*
   
<dt><i>GroupedNumeral</i>:
 
*
       
<dd><tt>(&nbsp;</tt><i>Non0Digit</i>
 
*
                   
<i>Digit</i><tt>?
 
*
                   
</tt><i>Digit</i><tt>?</tt>
 
*
       
<dd>&nbsp;&nbsp;&nbsp;&nbsp;<tt>(&nbsp;</tt><i>LocalGroupSeparator</i>
 
*
                         
<i>Digit</i>
 
*
                         
<i>Digit</i>
 
*
                         
<i>Digit</i><tt> )+ )</tt>
 
*
 
*
   
<dt><i>Numeral</i>:
 
*
       
<dd><tt>( ( </tt><i>Digit</i><tt>+ )
 
*
               
| </tt><i>GroupedNumeral</i><tt> )</tt>
 
*
 
*
   
<dt><a name="Integer-regex"><i>Integer</i>:</a>
 
*
       
<dd><tt>( [-+]? ( </tt><i>Numeral</i><tt>
 
*
                               
) )</tt>
 
*
       
<dd><tt>| </tt><i>LocalPositivePrefix</i> <i>Numeral</i>
 
*
                      
<i>LocalPositiveSuffix</i>
 
*
       
<dd><tt>| </tt><i>LocalNegativePrefix</i> <i>Numeral</i>
 
*
                 
<i>LocalNegativeSuffix</i>
 
*
 
*
   
<dt><i>DecimalNumeral</i>:
 
*
       
<dd><i>Numeral</i>
 
*
       
<dd><tt>| </tt><i>Numeral</i>
 
*
                 
<i>LocalDecimalSeparator</i>
 
*
                 
<i>Digit</i><tt>*</tt>
 
*
       
<dd><tt>| </tt><i>LocalDecimalSeparator</i>
 
*
                 
<i>Digit</i><tt>+</tt>
 
*
 
*
   
<dt><i>Exponent</i>:
 
*
       
<dd><tt>( [eE] [+-]? </tt><i>Digit</i><tt>+ )</tt>
 
*
 
*
   
<dt><a name="Decimal-regex"><i>Decimal</i>:</a>
 
*
       
<dd><tt>( [-+]? </tt><i>DecimalNumeral</i>
 
*
                         
<i>Exponent</i><tt>? )</tt>
 
*
       
<dd><tt>| </tt><i>LocalPositivePrefix</i>
 
*
                 
<i>DecimalNumeral</i>
 
*
                 
<i>LocalPositiveSuffix</i>
 
*
                 
<i>Exponent</i><tt>?</tt>
 
*
       
<dd><tt>| </tt><i>LocalNegativePrefix</i>
 
*
                 
<i>DecimalNumeral</i>
 
*
                 
<i>LocalNegativeSuffix</i>
 
*
                 
<i>Exponent</i><tt>?</tt>
 
*
 
*
   
<dt><i>HexFloat</i>:
 
*
       
<dd><tt>[-+]? 0[xX][0-9a-fA-F]*\.[0-9a-fA-F]+
 
*
                 
([pP][-+]?[0-9]+)?</tt>
 
*
 
*
   
<dt><i>NonNumber</i>:
 
*
       
<dd><tt>NaN
 
*
                          
| </tt><i>LocalNan</i><tt>
 
*
                          
| Infinity
 
*
                          
| </tt><i>LocalInfinity</i>
 
*
 
*
   
<dt><i>SignedNonNumber</i>:
 
*
       
<dd><tt>( [-+]? </tt><i>NonNumber</i><tt> )</tt>
 
*
       
<dd><tt>| </tt><i>LocalPositivePrefix</i>
 
*
                 
<i>NonNumber</i>
 
*
                 
<i>LocalPositiveSuffix</i>
 
*
       
<dd><tt>| </tt><i>LocalNegativePrefix</i>
 
*
                 
<i>NonNumber</i>
 
*
                 
<i>LocalNegativeSuffix</i>
 
*
 
*
   
<dt><a name="Float-regex"><i>Float</i></a>:
 
*
       
<dd><i>Decimal</i>
 
*
           
<tt>| </tt><i>HexFloat</i>
 
*
           
<tt>| </tt><i>SignedNonNumber</i>
 
*
 
* </dl>
 
* <p>Whitespace is not significant in the above regular expressions.
 
*
 
* @since
   
1.5
 
*/

public final class Scanner implements Iterator<String>, Closeable {

    
// Internal buffer used to hold input
    
private CharBuffer buf;

    
// Size of internal character buffer
    
private static final int BUFFER_SIZE = 1024; // change to 1024;

    
// The index into the buffer currently held by the Scanner
    
private int position;

    
// Internal matcher used for finding delimiters
    
private Matcher matcher;

    
// Pattern used to delimit tokens
    
private Pattern delimPattern;

    
// Pattern found in last hasNext operation
    
private Pattern hasNextPattern;

    
// Position after last hasNext operation
    
private int hasNextPosition;

    
// Result after last hasNext operation
    
private String hasNextResult;

    
// The input source
    
private Readable source;

    
// Boolean is true if source is done
    
private boolean sourceClosed = false;

    
// Boolean indicating more input is required
    
private boolean needInput = false;

    
// Boolean indicating if a delim has been skipped this operation
    
private boolean skipped = false;

    
// A store of a position that the scanner may fall back to
    
private int savedScannerPosition = -1;

    
// A cache of the last primitive type scanned
    
private Object typeCache = null;

    
// Boolean indicating if a match result is available
    
private boolean matchValid = false;

    
// Boolean indicating if this scanner has been closed
    
private boolean closed = false;

    
// The current radix used by this scanner
    
private int radix = 10;

    
// The default radix for this scanner
    
private int defaultRadix = 10;

    
// The locale used by this scanner
    
private Locale locale = null;

    
// A cache of the last few recently used Patterns
    
private LRUCache<String,Pattern> patternCache =
    
new LRUCache<String,Pattern>(7) {
        
protected Pattern create(String s) {
            
return Pattern.compile(s);
        
}
        
protected boolean hasName(Pattern p, String s) {
            
return p.pattern().equals(s);
        
}
    
};

    
// A holder of the last IOException encountered
    
private IOException lastException;

    
// A pattern for java whitespace
    
private static Pattern WHITESPACE_PATTERN = Pattern.compile(
                                                
"\\p{javaWhitespace}+");

    
// A pattern for any token
    
private static Pattern FIND_ANY_PATTERN = Pattern.compile("(?s).*");

    
// A pattern for non-ASCII digits
    
private static Pattern NON_ASCII_DIGIT = Pattern.compile(
        
"[\\p{javaDigit}&&[^0-9]]");

    
// Fields and methods to support scanning primitive types

    
/**
     
* Locale dependent values used to scan numbers
     
*/
    
private String groupSeparator = "\\,";
    
private String decimalSeparator = "\\.";
    
private String nanString = "NaN";
    
private String infinityString = "Infinity";
    
private String positivePrefix = "";
    
private String negativePrefix = "\\-";
    
private String positiveSuffix = "";
    
private String negativeSuffix = "";

    
/**
     
* Fields and an accessor method to match booleans
     
*/

    
private static volatile Pattern boolPattern;
    
private static final String BOOLEAN_PATTERN = "true|false";
    
private static Pattern boolPattern() {
        
Pattern bp = boolPattern;
        
if (bp == null)
            
boolPattern = bp = Pattern.compile(BOOLEAN_PATTERN,
                                          
Pattern.CASE_INSENSITIVE);
        
return bp;
    
}

    
/**
     
* Fields and methods to match bytes, shorts, ints, and longs
     
*/

    
private Pattern integerPattern;
    
private String digits = "0123456789abcdefghijklmnopqrstuvwxyz";
    
private String non0Digit = "[\\p{javaDigit}&&[^0]]";
    
private int SIMPLE_GROUP_INDEX = 5;
    
private String buildIntegerPatternString() {
        
String radixDigits = digits.substring(0, radix);
        
// \\p{javaDigit} is not guaranteed to be appropriate
        
// here but what can we do? The final authority will be
        
// whatever parse method is invoked, so ultimately the
        
// Scanner will do the right thing
        
String digit = "((?i)["+radixDigits+"]|\\p{javaDigit})";
        
String groupedNumeral = "("+non0Digit+digit+"?"+digit+"?("+
                                
groupSeparator+digit+digit+digit+")+)";
        
// digit++ is the possessive form which is necessary for reducing
        
// backtracking that would otherwise cause unacceptable performance
        
String numeral = "(("+ digit+"++)|"+groupedNumeral+")";
        
String javaStyleInteger = "([-+]?(" + numeral + "))";
        
String negativeInteger = negativePrefix + numeral + negativeSuffix;
        
String positiveInteger = positivePrefix + numeral + positiveSuffix;
        
return "("+ javaStyleInteger + ")|(" +
            
positiveInteger + ")|(" +
            
negativeInteger + ")";
    
}
    
private Pattern integerPattern() {
        
if (integerPattern == null) {
            
integerPattern = patternCache.forName(buildIntegerPatternString());
        
}
        
return integerPattern;
    
}

    
/**
     
* Fields and an accessor method to match line separators
     
*/

    
private static volatile Pattern separatorPattern;
    
private static volatile Pattern linePattern;
    
private static final String LINE_SEPARATOR_PATTERN =
                                           
"\r\n|[\n\r\u2028\u2029\u0085]";
    
private static final String LINE_PATTERN = ".*("+LINE_SEPARATOR_PATTERN+")|.+$";

    
private static Pattern separatorPattern() {
        
Pattern sp = separatorPattern;
        
if (sp == null)
            
separatorPattern = sp = Pattern.compile(LINE_SEPARATOR_PATTERN);
        
return sp;
    
}

    
private static Pattern linePattern() {
        
Pattern lp = linePattern;
        
if (lp == null)
            
linePattern = lp = Pattern.compile(LINE_PATTERN);
        
return lp;
    
}

    
/**
     
* Fields and methods to match floats and doubles
     
*/

    
private Pattern floatPattern;
    
private Pattern decimalPattern;
    
private void buildFloatAndDecimalPattern() {
        
// \\p{javaDigit} may not be perfect, see above
        
String digit = "([0-9]|(\\p{javaDigit}))";
        
String exponent = "([eE][+-]?"+digit+"+)?";
        
String groupedNumeral = "("+non0Digit+digit+"?"+digit+"?("+
                                
groupSeparator+digit+digit+digit+")+)";
        
// Once again digit++ is used for performance, as above
        
String numeral = "(("+digit+"++)|"+groupedNumeral+")";
        
String decimalNumeral = "("+numeral+"|"+numeral +
            
decimalSeparator + digit + "*+|"+ decimalSeparator +
            
digit + "++)";
        
String nonNumber = "(NaN|"+nanString+"|Infinity|"+
                               
infinityString+")";
        
String positiveFloat = "(" + positivePrefix + decimalNumeral +
                            
positiveSuffix + exponent + ")";
        
String negativeFloat = "(" + negativePrefix + decimalNumeral +
                            
negativeSuffix + exponent + ")";
        
String decimal = "(([-+]?" + decimalNumeral + exponent + ")|"+
            
positiveFloat + "|" + negativeFloat + ")";
        
String hexFloat =
            
"[-+]?0[xX][0-9a-fA-F]*\\.[0-9a-fA-F]+([pP][-+]?[0-9]+)?";
        
String positiveNonNumber = "(" + positivePrefix + nonNumber +
                            
positiveSuffix + ")";
        
String negativeNonNumber = "(" + negativePrefix + nonNumber +
                            
negativeSuffix + ")";
        
String signedNonNumber = "(([-+]?"+nonNumber+")|" +
                                 
positiveNonNumber + "|" +
                                 
negativeNonNumber + ")";
        
floatPattern = Pattern.compile(decimal + "|" + hexFloat + "|" +
                                       
signedNonNumber);
        
decimalPattern = Pattern.compile(decimal);
    
}
    
private Pattern floatPattern() {
        
if (floatPattern == null) {
            
buildFloatAndDecimalPattern();
        
}
        
return floatPattern;
    
}
    
private Pattern decimalPattern() {
        
if (decimalPattern == null) {
            
buildFloatAndDecimalPattern();
        
}
        
return decimalPattern;
    
}

    
// Constructors

    
/**
     
* Constructs a <code>Scanner</code> that returns values scanned
     
* from the specified source delimited by the specified pattern.
     
*
     
* @param source A character source implementing the Readable interface
     
* @param pattern A delimiting pattern
     
*/

    
private Scanner(Readable source, Pattern pattern) {
        
assert source != null : "source should not be null";
        
assert pattern != null : "pattern should not be null";
        
this.source = source;
        
delimPattern = pattern;
        
buf = CharBuffer.allocate(BUFFER_SIZE);
        
buf.limit(0);
        
matcher = delimPattern.matcher(buf);
        
matcher.useTransparentBounds(true);
        
matcher.useAnchoringBounds(false);
        
useLocale(Locale.getDefault(Locale.Category.FORMAT));
    
}

    
/**
     
* Constructs a new <code>Scanner</code> that produces values scanned
     
* from the specified source.
     
*
     
* @param
  
source A character source implementing the {@link Readable}
     
*
         
interface
     
*/

    
public Scanner(Readable source) {
        
this(Objects.requireNonNull(source, "source"), WHITESPACE_PATTERN);
    
}

    
/**
     
* Constructs a new <code>Scanner</code> that produces values scanned
     
* from the specified input stream. Bytes from the stream are converted
     
* into characters using the underlying platform's
     
* {@linkplain java.nio.charset.Charset#defaultCharset() default charset}.
     
*
     
* @param
  
source An input stream to be scanned
     
*/

    
public Scanner(InputStream source) {
        
this(new InputStreamReader(source), WHITESPACE_PATTERN);
    
}

    
/**
     
* Constructs a new <code>Scanner</code> that produces values scanned
     
* from the specified input stream. Bytes from the stream are converted
     
* into characters using the specified charset.
     
*
     
* @param
  
source An input stream to be scanned
     
* @param charsetName The encoding type used to convert bytes from the
     
*
        
stream into characters to be scanned
     
* @throws IllegalArgumentException if the specified character set
     
*
         
does not exist
     
*/

    
public Scanner(InputStream source, String charsetName) {
        
this(makeReadable(Objects.requireNonNull(source, "source"), toCharset(charsetName)),
             
WHITESPACE_PATTERN);
    
}

    
/**
     
* Returns a charset object for the given charset name.
     
* @throws NullPointerException
          
is csn is null
     
* @throws IllegalArgumentException
      
if the charset is not supported
     
*/

    
private static Charset toCharset(String csn) {
        
Objects.requireNonNull(csn, "charsetName");
        
try {
            
return Charset.forName(csn);
        
} catch (IllegalCharsetNameException|UnsupportedCharsetException e) {
            
// IllegalArgumentException should be thrown
            
throw new IllegalArgumentException(e);
        
}
    
}

    
private static Readable makeReadable(InputStream source, Charset charset) {
        
return new InputStreamReader(source, charset);
    
}

    
/**
     
* Constructs a new <code>Scanner</code> that produces values scanned
     
* from the specified file. Bytes from the file are converted into
     
* characters using the underlying platform's
     
* {@linkplain java.nio.charset.Charset#defaultCharset() default charset}.
     
*
     
* @param
  
source A file to be scanned
     
* @throws FileNotFoundException if source is not found
     
*/

    
public Scanner(File source) throws FileNotFoundException {
        
this((ReadableByteChannel)(new FileInputStream(source).getChannel()));
    
}

    
/**
     
* Constructs a new <code>Scanner</code> that produces values scanned
     
* from the specified file. Bytes from the file are converted into
     
* characters using the specified charset.
     
*
     
* @param
  
source A file to be scanned
     
* @param charsetName The encoding type used to convert bytes from the file
     
*
        
into characters to be scanned
     
* @throws FileNotFoundException if source is not found
     
* @throws IllegalArgumentException if the specified encoding is
     
*
         
not found
     
*/

    
public Scanner(File source, String charsetName)
        
throws FileNotFoundException
    
{
        
this(Objects.requireNonNull(source), toDecoder(charsetName));
    
}

    
private Scanner(File source, CharsetDecoder dec)
        
throws FileNotFoundException
    
{
        
this(makeReadable((ReadableByteChannel)(new FileInputStream(source).getChannel()), dec));
    
}

    
private static CharsetDecoder toDecoder(String charsetName) {
        
Objects.requireNonNull(charsetName, "charsetName");
        
try {
            
return Charset.forName(charsetName).newDecoder();
        
} catch (IllegalCharsetNameException|UnsupportedCharsetException unused) {
            
throw new IllegalArgumentException(charsetName);
        
}
    
}

    
private static Readable makeReadable(ReadableByteChannel source,
                                         
CharsetDecoder dec) {
        
return Channels.newReader(source, dec, -1);
    
}

    
/**
     
* Constructs a new <code>Scanner</code> that produces values scanned
     
* from the specified file. Bytes from the file are converted into
     
* characters using the underlying platform's
     
* {@linkplain java.nio.charset.Charset#defaultCharset() default charset}.
     
*
     
* @param
   
source
     
*
          
the path to the file to be scanned
     
* @throws
  
IOException
     
*
          
if an I/O error occurs opening source
     
*
     
* @since
   
1.7
     
*/

    
public Scanner(Path source)
        
throws IOException
    
{
        
this(Files.newInputStream(source));
    
}

    
/**
     
* Constructs a new <code>Scanner</code> that produces values scanned
     
* from the specified file. Bytes from the file are converted into
     
* characters using the specified charset.
     
*
     
* @param
   
source
     
*
          
the path to the file to be scanned
     
* @param
   
charsetName
     
*
          
The encoding type used to convert bytes from the file
     
*
          
into characters to be scanned
     
* @throws
  
IOException
     
*
          
if an I/O error occurs opening source
     
* @throws
  
IllegalArgumentException
     
*
          
if the specified encoding is not found
     
* @since
   
1.7
     
*/

    
public Scanner(Path source, String charsetName) throws IOException {
        
this(Objects.requireNonNull(source), toCharset(charsetName));
    
}

    
private Scanner(Path source, Charset charset)
  
throws IOException {
        
this(makeReadable(Files.newInputStream(source), charset));
    
}

    
/**
     
* Constructs a new <code>Scanner</code> that produces values scanned
     
* from the specified string.
     
*
     
* @param
  
source A string to scan
     
*/

    
public Scanner(String source) {
        
this(new StringReader(source), WHITESPACE_PATTERN);
    
}

    
/**
     
* Constructs a new <code>Scanner</code> that produces values scanned
     
* from the specified channel. Bytes from the source are converted into
     
* characters using the underlying platform's
     
* {@linkplain java.nio.charset.Charset#defaultCharset() default charset}.
     
*
     
* @param
  
source A channel to scan
     
*/

    
public Scanner(ReadableByteChannel source) {
        
this(makeReadable(Objects.requireNonNull(source, "source")),
             
WHITESPACE_PATTERN);
    
}

    
private static Readable makeReadable(ReadableByteChannel source) {
        
return makeReadable(source, Charset.defaultCharset().newDecoder());
    
}

    
/**
     
* Constructs a new <code>Scanner</code> that produces values scanned
     
* from the specified channel. Bytes from the source are converted into
     
* characters using the specified charset.
     
*
     
* @param
  
source A channel to scan
     
* @param charsetName The encoding type used to convert bytes from the
     
*
        
channel into characters to be scanned
     
* @throws IllegalArgumentException if the specified character set
     
*
         
does not exist
     
*/

    
public Scanner(ReadableByteChannel source, String charsetName) {
        
this(makeReadable(Objects.requireNonNull(source, "source"), toDecoder(charsetName)),
             
WHITESPACE_PATTERN);
    
}

    
// Private primitives used to support scanning

    
private void saveState() {
        
savedScannerPosition = position;
    
}

    
private void revertState() {
        
this.position = savedScannerPosition;
        
savedScannerPosition = -1;
        
skipped = false;
    
}

    
private boolean revertState(boolean b) {
        
this.position = savedScannerPosition;
        
savedScannerPosition = -1;
        
skipped = false;
        
return b;
    
}

    
private void cacheResult() {
        
hasNextResult = matcher.group();
        
hasNextPosition = matcher.end();
        
hasNextPattern = matcher.pattern();
    
}

    
private void cacheResult(String result) {
        
hasNextResult = result;
        
hasNextPosition = matcher.end();
        
hasNextPattern = matcher.pattern();
    
}

    
// Clears both regular cache and type cache
    
private void clearCaches() {
        
hasNextPattern = null;
        
typeCache = null;
    
}

    
// Also clears both the regular cache and the type cache
    
private String getCachedResult() {
        
position = hasNextPosition;
        
hasNextPattern = null;
        
typeCache = null;
        
return hasNextResult;
    
}

    
// Also clears both the regular cache and the type cache
    
private void useTypeCache() {
        
if (closed)
            
throw new IllegalStateException("Scanner closed");
        
position = hasNextPosition;
        
hasNextPattern = null;
        
typeCache = null;
    
}

    
// Tries to read more input. May block.
    
private void readInput() {
        
if (buf.limit() == buf.capacity())
            
makeSpace();

        
// Prepare to receive data
        
int p = buf.position();
        
buf.position(buf.limit());
        
buf.limit(buf.capacity());

        
int n = 0;
        
try {
            
n = source.read(buf);
        
} catch (IOException ioe) {
            
lastException = ioe;
            
n = -1;
        
}

        
if (n == -1) {
            
sourceClosed = true;
            
needInput = false;
        
}

        
if (n > 0)
            
needInput = false;

        
// Restore current position and limit for reading
        
buf.limit(buf.position());
        
buf.position(p);
    
}

    
// After this method is called there will either be an exception
    
// or else there will be space in the buffer
    
private boolean makeSpace() {
        
clearCaches();
        
int offset = savedScannerPosition == -1 ?
            
position : savedScannerPosition;
        
buf.position(offset);
        
// Gain space by compacting buffer
        
if (offset > 0) {
            
buf.compact();
            
translateSavedIndexes(offset);
            
position -= offset;
            
buf.flip();
            
return true;
        
}
        
// Gain space by growing buffer
        
int newSize = buf.capacity() * 2;
        
CharBuffer newBuf = CharBuffer.allocate(newSize);
        
newBuf.put(buf);
        
newBuf.flip();
        
translateSavedIndexes(offset);
        
position -= offset;
        
buf = newBuf;
        
matcher.reset(buf);
        
return true;
    
}

    
// When a buffer compaction/reallocation occurs the saved indexes must
    
// be modified appropriately
    
private void translateSavedIndexes(int offset) {
        
if (savedScannerPosition != -1)
            
savedScannerPosition -= offset;
    
}

    
// If we are at the end of input then NoSuchElement;
    
// If there is still input left then InputMismatch
    
private void throwFor() {
        
skipped = false;
        
if ((sourceClosed) && (position == buf.limit()))
            
throw new NoSuchElementException();
        
else
            
throw new
InputMismatchException();
    
}

    
// Returns true if a complete token or partial token is in the buffer.
    
// It is not necessary to find a complete token since a partial token
    
// means that there will be another token with or without more input.
    
private boolean hasTokenInBuffer() {
        
matchValid = false;
        
matcher.usePattern(delimPattern);
        
matcher.region(position, buf.limit());

        
// Skip delims first
        
if (matcher.lookingAt())
            
position = matcher.end();

        
// If we are sitting at the end, no more tokens in buffer
        
if (position == buf.limit())
            
return false;

        
return true;
    
}

    
/*
     
* Returns a "complete token" that matches the specified pattern
     
*
     
* A token is complete if surrounded by delims; a partial token
     
* is prefixed by delims but not postfixed by them
     
*
     
* The position is advanced to the end of that complete token
     
*
     
* Pattern == null means accept any token at all
     
*
     
* Triple return:
     
* 1. valid string means it was found
     
* 2. null with needInput=false means we won't ever find it
     
* 3. null with needInput=true means try again after readInput
     
*/

    
private String getCompleteTokenInBuffer(Pattern pattern) {
        
matchValid = false;

        
// Skip delims first
        
matcher.usePattern(delimPattern);
        
if (!skipped) { // Enforcing only one skip of leading delims
            
matcher.region(position, buf.limit());
            
if (matcher.lookingAt()) {
                
// If more input could extend the delimiters then we must wait
                
// for more input
                
if (matcher.hitEnd() && !sourceClosed) {
                    
needInput = true;
                    
return null;
                
}
                
// The delims were whole and the matcher should skip them
                
skipped = true;
                
position = matcher.end();
            
}
        
}

        
// If we are sitting at the end, no more tokens in buffer
        
if (position == buf.limit()) {
            
if (sourceClosed)
                
return null;
            
needInput = true;
            
return null;
        
}

        
// Must look for next delims. Simply attempting to match the
        
// pattern at this point may find a match but it might not be
        
// the first longest match because of missing input, or it might
        
// match a partial token instead of the whole thing.

        
// Then look for next delims
        
matcher.region(position, buf.limit());
        
boolean foundNextDelim = matcher.find();
        
if (foundNextDelim && (matcher.end() == position)) {
            
// Zero length delimiter match; we should find the next one
            
// using the automatic advance past a zero length match;
            
// Otherwise we have just found the same one we just skipped
            
foundNextDelim = matcher.find();
        
}
        
if (foundNextDelim) {
            
// In the rare case that more input could cause the match
            
// to be lost and there is more input coming we must wait
            
// for more input. Note that hitting the end is okay as long
            
// as the match cannot go away. It is the beginning of the
            
// next delims we want to be sure about, we don't care if
            
// they potentially extend further.
            
if (matcher.requireEnd() && !sourceClosed) {
                
needInput = true;
                
return null;
            
}
            
int tokenEnd = matcher.start();
            
// There is a complete token.
            
if (pattern == null) {
                
// Must continue with match to provide valid MatchResult
                
pattern = FIND_ANY_PATTERN;
            
}
            
//
  
Attempt to match against the desired pattern
            
matcher.usePattern(pattern);
            
matcher.region(position, tokenEnd);
            
if (matcher.matches()) {
                
String s = matcher.group();
                
position = matcher.end();
                
return s;
            
} else { // Complete token but it does not match
                
return null;
            
}
        
}

        
// If we can't find the next delims but no more input is coming,
        
// then we can treat the remainder as a whole token
        
if (sourceClosed) {
            
if (pattern == null) {
                
// Must continue with match to provide valid MatchResult
                
pattern = FIND_ANY_PATTERN;
            
}
            
// Last token; Match the pattern here or throw
            
matcher.usePattern(pattern);
            
matcher.region(position, buf.limit());
            
if (matcher.matches()) {
                
String s = matcher.group();
                
position = matcher.end();
                
return s;
            
}
            
// Last piece does not match
            
return null;
        
}

        
// There is a partial token in the buffer; must read more
        
// to complete it
        
needInput = true;
        
return null;
    
}

    
// Finds the specified pattern in the buffer up to horizon.
    
// Returns a match for the specified input pattern.
    
private String findPatternInBuffer(Pattern pattern, int horizon) {
        
matchValid = false;
        
matcher.usePattern(pattern);
        
int bufferLimit = buf.limit();
        
int horizonLimit = -1;
        
int searchLimit = bufferLimit;
        
if (horizon > 0) {
            
horizonLimit = position + horizon;
            
if (horizonLimit < bufferLimit)
                
searchLimit = horizonLimit;
        
}
        
matcher.region(position, searchLimit);
        
if (matcher.find()) {
            
if (matcher.hitEnd() && (!sourceClosed)) {
                
// The match may be longer if didn't hit horizon or real end
                
if (searchLimit != horizonLimit) {
                     
// Hit an artificial end; try to extend the match
                    
needInput = true;
                    
return null;
                
}
                
// The match could go away depending on what is next
                
if ((searchLimit == horizonLimit) && matcher.requireEnd()) {
                    
// Rare case: we hit the end of input and it happens
                    
// that it is at the horizon and the end of input is
                    
// required for the match.
                    
needInput = true;
                    
return null;
                
}
            
}
            
// Did not hit end, or hit real end, or hit horizon
            
position = matcher.end();
            
return matcher.group();
        
}

        
if (sourceClosed)
            
return null;

        
// If there is no specified horizon, or if we have not searched
        
// to the specified horizon yet, get more input
        
if ((horizon == 0) || (searchLimit != horizonLimit))
            
needInput = true;
        
return null;
    
}

    
// Returns a match for the specified input pattern anchored at
    
// the current position
    
private String matchPatternInBuffer(Pattern pattern) {
        
matchValid = false;
        
matcher.usePattern(pattern);
        
matcher.region(position, buf.limit());
        
if (matcher.lookingAt()) {
            
if (matcher.hitEnd() && (!sourceClosed)) {
                
// Get more input and try again
                
needInput = true;
                
return null;
            
}
            
position = matcher.end();
            
return matcher.group();
        
}

        
if (sourceClosed)
            
return null;

        
// Read more to find pattern
        
needInput = true;
        
return null;
    
}

    
// Throws if the scanner is closed
    
private void ensureOpen() {
        
if (closed)
            
throw new IllegalStateException("Scanner closed");
    
}

    
// Public methods

    
/**
     
* Closes this scanner.
     
*
     
* <p> If this scanner has not yet been closed then if its underlying
     
* {@linkplain java.lang.Readable readable} also implements the {@link
     
* java.io.Closeable} interface then the readable's <tt>close</tt> method
     
* will be invoked.
  
If this scanner is already closed then invoking this
     
* method will have no effect.
     
*
     
* <p>Attempting to perform search operations after a scanner has
     
* been closed will result in an {@link IllegalStateException}.
     
*
     
*/

    
public void close() {
        
if (closed)
            
return;
        
if (source instanceof Closeable) {
            
try {
                
((Closeable)source).close();
            
} catch (IOException ioe) {
                
lastException = ioe;
            
}
        
}
        
sourceClosed = true;
        
source = null;
        
closed = true;
    
}

    
/**
     
* Returns the <code>IOException</code> last thrown by this
     
* <code>Scanner</code>'s underlying <code>Readable</code>. This method
     
* returns <code>null</code> if no such exception exists.
     
*
     
* @return the last exception thrown by this scanner's readable
     
*/

    
public IOException ioException() {
        
return lastException;
    
}

    
/**
     
* Returns the <code>Pattern</code> this <code>Scanner</code> is currently
     
* using to match delimiters.
     
*
     
* @return this scanner's delimiting pattern.
     
*/

    
public Pattern delimiter() {
        
return delimPattern;
    
}

    
/**
     
* Sets this scanner's delimiting pattern to the specified pattern.
     
*
     
* @param pattern A delimiting pattern
     
* @return this scanner
     
*/

    
public Scanner useDelimiter(Pattern pattern) {
        
delimPattern = pattern;
        
return this;
    
}

    
/**
     
* Sets this scanner's delimiting pattern to a pattern constructed from
     
* the specified <code>String</code>.
     
*
     
* <p> An invocation of this method of the form
     
* <tt>useDelimiter(pattern)</tt> behaves in exactly the same way as the
     
* invocation <tt>useDelimiter(Pattern.compile(pattern))</tt>.
     
*
     
* <p> Invoking the {@link #reset} method will set the scanner's delimiter
     
* to the
 
<a href= "#default-delimiter">default</a>.
     
*
     
* @param pattern A string specifying a delimiting pattern
     
* @return this scanner
     
*/

    
public Scanner useDelimiter(String pattern) {
        
delimPattern = patternCache.forName(pattern);
        
return this;
    
}

    
/**
     
* Returns this scanner's locale.
     
*
     
* <p>A scanner's locale affects many elements of its default
     
* primitive matching regular expressions; see
     
*
 
<a href= "#localized-numbers">localized numbers</a>
 
above.
     
*
     
* @return this scanner's locale
     
*/

    
public Locale locale() {
        
return this.locale;
    
}

    
/**
     
* Sets this scanner's locale to the specified locale.
     
*
     
* <p>A scanner's locale affects many elements of its default
     
* primitive matching regular expressions; see
     
*
 
<a href= "#localized-numbers">localized numbers</a>
 
above.
     
*
     
* <p>Invoking the {@link #reset} method will set the scanner's locale to
     
* the
 
<a href= "#initial-locale">initial locale</a>.
     
*
     
* @param locale A string specifying the locale to use
     
* @return this scanner
     
*/

    
public Scanner useLocale(Locale locale) {
        
if (locale.equals(this.locale))
            
return this;

        
this.locale = locale;
        
DecimalFormat df =
            
(DecimalFormat)NumberFormat.getNumberInstance(locale);
        
DecimalFormatSymbols dfs = DecimalFormatSymbols.getInstance(locale);

        
// These must be literalized to avoid collision with regex
        
// metacharacters such as dot or parenthesis
        
groupSeparator =
   
"\\" + dfs.getGroupingSeparator();
        
decimalSeparator = "\\" + dfs.getDecimalSeparator();

        
// Quoting the nonzero length locale-specific things
        
// to avoid potential conflict with metacharacters
        
nanString = "\\Q" + dfs.getNaN() + "\\E";
        
infinityString = "\\Q" + dfs.getInfinity() + "\\E";
        
positivePrefix = df.getPositivePrefix();
        
if (positivePrefix.length() > 0)
            
positivePrefix = "\\Q" + positivePrefix + "\\E";
        
negativePrefix = df.getNegativePrefix();
        
if (negativePrefix.length() > 0)
            
negativePrefix = "\\Q" + negativePrefix + "\\E";
        
positiveSuffix = df.getPositiveSuffix();
        
if (positiveSuffix.length() > 0)
            
positiveSuffix = "\\Q" + positiveSuffix + "\\E";
        
negativeSuffix = df.getNegativeSuffix();
        
if (negativeSuffix.length() > 0)
            
negativeSuffix = "\\Q" + negativeSuffix + "\\E";

        
// Force rebuilding and recompilation of locale dependent
        
// primitive patterns
        
integerPattern = null;
        
floatPattern = null;

        
return this;
    
}

    
/**
     
* Returns this scanner's default radix.
     
*
     
* <p>A scanner's radix affects elements of its default
     
* number matching regular expressions; see
     
*
 
<a href= "#localized-numbers">localized numbers</a>
 
above.
     
*
     
* @return the default radix of this scanner
     
*/

    
public int radix() {
        
return this.defaultRadix;
    
}

    
/**
     
* Sets this scanner's default radix to the specified radix.
     
*
     
* <p>A scanner's radix affects elements of its default
     
* number matching regular expressions; see
     
*
 
<a href= "#localized-numbers">localized numbers</a>
 
above.
     
*
     
* <p>If the radix is less than <code>Character.MIN_RADIX</code>
     
* or greater than <code>Character.MAX_RADIX</code>, then an
     
* <code>IllegalArgumentException</code> is thrown.
     
*
     
* <p>Invoking the {@link #reset} method will set the scanner's radix to
     
* <code>10</code>.
     
*
     
* @param radix The radix to use when scanning numbers
     
* @return this scanner
     
* @throws IllegalArgumentException if radix is out of range
     
*/

    
public Scanner useRadix(int radix) {
        
if ((radix < Character.MIN_RADIX) || (radix > Character.MAX_RADIX))
            
throw new IllegalArgumentException("radix:"+radix);

        
if (this.defaultRadix == radix)
            
return this;
        
this.defaultRadix = radix;
        
// Force rebuilding and recompilation of radix dependent patterns
        
integerPattern = null;
        
return this;
    
}

    
// The next operation should occur in the specified radix but
    
// the default is left untouched.
    
private void setRadix(int radix) {
        
if (this.radix != radix) {
            
// Force rebuilding and recompilation of radix dependent patterns
            
integerPattern = null;
            
this.radix = radix;
        
}
    
}

    
/**
     
* Returns the match result of the last scanning operation performed
     
* by this scanner. This method throws <code>IllegalStateException</code>
     
* if no match has been performed, or if the last match was
     
* not successful.
     
*
     
* <p>The various <code>next</code>methods of <code>Scanner</code>
     
* make a match result available if they complete without throwing an
     
* exception. For instance, after an invocation of the {@link #nextInt}
     
* method that returned an int, this method returns a
     
* <code>MatchResult</code> for the search of the
     
*
 
<a href="#Integer-regex"><i>Integer</i></a>
 
regular expression
     
* defined above. Similarly the {@link #findInLine},
     
* {@link #findWithinHorizon}, and {@link #skip} methods will make a
     
* match available if they succeed.
     
*
     
* @return a match result for the last match operation
     
* @throws IllegalStateException
  
If no match result is available
     
*/

    
public MatchResult match() {
        
if (!matchValid)
            
throw new IllegalStateException("No match result available");
        
return matcher.toMatchResult();
    
}

    
/**
     
* <p>Returns the string representation of this <code>Scanner</code>. The
     
* string representation of a <code>Scanner</code> contains information
     
* that may be useful for debugging. The exact format is unspecified.
     
*
     
* @return
  
The string representation of this scanner
     
*/

    
public String toString() {
        
StringBuilder sb = new StringBuilder();
        
sb.append("java.util.Scanner");
        
sb.append("[delimiters=" + delimPattern + "]");
        
sb.append("[position=" + position + "]");
        
sb.append("[match valid=" + matchValid + "]");
        
sb.append("[need input=" + needInput + "]");
        
sb.append("[source closed=" + sourceClosed + "]");
        
sb.append("[skipped=" + skipped + "]");
        
sb.append("[group separator=" + groupSeparator + "]");
        
sb.append("[decimal separator=" + decimalSeparator + "]");
        
sb.append("[positive prefix=" + positivePrefix + "]");
        
sb.append("[negative prefix=" + negativePrefix + "]");
        
sb.append("[positive suffix=" + positiveSuffix + "]");
        
sb.append("[negative suffix=" + negativeSuffix + "]");
        
sb.append("[NaN string=" + nanString + "]");
        
sb.append("[infinity string=" + infinityString + "]");
        
return sb.toString();
    
}

    
/**
     
* Returns true if this scanner has another token in its input.
     
* This method may block while waiting for input to scan.
     
* The scanner does not advance past any input.
     
*
     
* @return true if and only if this scanner has another token
     
* @throws IllegalStateException if this scanner is closed
     
*
 

     
*/

    
public boolean hasNext() {
        
ensureOpen();
        
saveState();
        
while (!sourceClosed) {
            
if (hasTokenInBuffer())
                
return revertState(true);
            
readInput();
        
}
        
boolean result = hasTokenInBuffer();
        
return revertState(result);
    
}

    
/**
     
* Finds and returns the next complete token from this scanner.
     
* A complete token is preceded and followed by input that matches
     
* the delimiter pattern. This method may block while waiting for input
     
* to scan, even if a previous invocation of {@link #hasNext} returned
     
* <code>true</code>.
     
*
     
* @return the next token
     
* @throws NoSuchElementException if no more tokens are available
     
* @throws IllegalStateException if this scanner is closed
     
*
 

     
*/

    
public String next() {
        
ensureOpen();
        
clearCaches();

        
while (true) {
            
String token = getCompleteTokenInBuffer(null);
            
if (token != null) {
                
matchValid = true;
                
skipped = false;
                
return token;
            
}
            
if (needInput)
                
readInput();
            
else
                
throwFor();
        
}
    
}

    
/**
     
* The remove operation is not supported by this implementation of
     
* <code>Iterator</code>.
     
*
     
* @throws UnsupportedOperationException if this method is invoked.
     
*
 

     
*/

    
public void remove() {
        
throw new UnsupportedOperationException();
    
}

    
/**
     
* Returns true if the next token matches the pattern constructed from the
     
* specified string. The scanner does not advance past any input.
     
*
     
* <p> An invocation of this method of the form <tt>hasNext(pattern)</tt>
     
* behaves in exactly the same way as the invocation
     
* <tt>hasNext(Pattern.compile(pattern))</tt>.
     
*
     
* @param pattern a string specifying the pattern to scan
     
* @return true if and only if this scanner has another token matching
     
*
         
the specified pattern
     
* @throws IllegalStateException if this scanner is closed
     
*/

    
public boolean hasNext(String pattern)
  
{
        
return hasNext(patternCache.forName(pattern));
    
}

    
/**
     
* Returns the next token if it matches the pattern constructed from the
     
* specified string.
  
If the match is successful, the scanner advances
     
* past the input that matched the pattern.
     
*
     
* <p> An invocation of this method of the form <tt>next(pattern)</tt>
     
* behaves in exactly the same way as the invocation
     
* <tt>next(Pattern.compile(pattern))</tt>.
     
*
     
* @param pattern a string specifying the pattern to scan
     
* @return the next token
     
* @throws NoSuchElementException if no such tokens are available
     
* @throws IllegalStateException if this scanner is closed
     
*/

    
public String next(String pattern)
  
{
        
return next(patternCache.forName(pattern));
    
}

    
/**
     
* Returns true if the next complete token matches the specified pattern.
     
* A complete token is prefixed and postfixed by input that matches
     
* the delimiter pattern. This method may block while waiting for input.
     
* The scanner does not advance past any input.
     
*
     
* @param pattern the pattern to scan for
     
* @return true if and only if this scanner has another token matching
     
*
         
the specified pattern
     
* @throws IllegalStateException if this scanner is closed
     
*/

    
public boolean hasNext(Pattern pattern) {
        
ensureOpen();
        
if (pattern == null)
            
throw new NullPointerException();
        
hasNextPattern = null;
        
saveState();

        
while (true) {
            
if (getCompleteTokenInBuffer(pattern) != null) {
                
matchValid = true;
                
cacheResult();
                
return revertState(true);
            
}
            
if (needInput)
                
readInput();
            
else
                
return
revertState(false);
        
}
    
}

    
/**
     
* Returns the next token if it matches the specified pattern. This
     
* method may block while waiting for input to scan, even if a previous
     
* invocation of {@link #hasNext(Pattern)} returned <code>true</code>.
     
* If the match is successful, the scanner advances past the input that
     
* matched the pattern.
     
*
     
* @param pattern the pattern to scan for
     
* @return the next token
     
* @throws NoSuchElementException if no more tokens are available
     
* @throws IllegalStateException if this scanner is closed
     
*/

    
public String next(Pattern pattern) {
        
ensureOpen();
        
if (pattern == null)
            
throw new NullPointerException();

        
// Did we already find this pattern?
        
if (hasNextPattern == pattern)
            
return getCachedResult();
        
clearCaches();

        
// Search for the pattern
        
while (true) {
            
String token = getCompleteTokenInBuffer(pattern);
            
if (token != null) {
                
matchValid = true;
                
skipped = false;
                
return token;
            
}
            
if (needInput)
                
readInput();
            
else
                
throwFor();
        
}
    
}

    
/**
     
* Returns true if there is another line in the input of this scanner.
     
* This method may block while waiting for input. The scanner does not
     
* advance past any input.
     
*
     
* @return true if and only if this scanner has another line of input
     
* @throws IllegalStateException if this scanner is closed
     
*/

    
public boolean hasNextLine() {
        
saveState();

        
String result = findWithinHorizon(linePattern(), 0);
        
if (result != null) {
            
MatchResult mr = this.match();
            
String lineSep = mr.group(1);
            
if (lineSep != null) {
                
result = result.substring(0, result.length() -
                                          
lineSep.length());
                
cacheResult(result);

            
} else {
                
cacheResult();
            
}
        
}
        
revertState();
        
return (result != null);
    
}

    
/**
     
* Advances this scanner past the current line and returns the input
     
* that was skipped.
     
*
     
* This method returns the rest of the current line, excluding any line
     
* separator at the end. The position is set to the beginning of the next
     
* line.
     
*
     
* <p>Since this method continues to search through the input looking
     
* for a line separator, it may buffer all of the input searching for
     
* the line to skip if no line separators are present.
     
*
     
* @return the line that was skipped
     
* @throws NoSuchElementException if no line was found
     
* @throws IllegalStateException if this scanner is closed
     
*/

    
public String nextLine() {
        
if (hasNextPattern == linePattern())
            
return getCachedResult();
        
clearCaches();

        
String result = findWithinHorizon(linePattern, 0);
        
if (result == null)
            
throw new NoSuchElementException("No line found");
        
MatchResult mr = this.match();
        
String lineSep = mr.group(1);
        
if (lineSep != null)
            
result = result.substring(0, result.length() - lineSep.length());
        
if (result == null)
            
throw new NoSuchElementException();
        
else
            
return
result;
    
}

    
// Public methods that ignore delimiters

    
/**
     
* Attempts to find the next occurrence of a pattern constructed from the
     
* specified string, ignoring delimiters.
     
*
     
* <p>An invocation of this method of the form <tt>findInLine(pattern)</tt>
     
* behaves in exactly the same way as the invocation
     
* <tt>findInLine(Pattern.compile(pattern))</tt>.
     
*
     
* @param pattern a string specifying the pattern to search for
     
* @return the text that matched the specified pattern
     
* @throws IllegalStateException if this scanner is closed
     
*/

    
public String findInLine(String pattern) {
        
return findInLine(patternCache.forName(pattern));
    
}

    
/**
     
* Attempts to find the next occurrence of the specified pattern ignoring
     
* delimiters. If the pattern is found before the next line separator, the
     
* scanner advances past the input that matched and returns the string that
     
* matched the pattern.
     
* If no such pattern is detected in the input up to the next line
     
* separator, then <code>null</code> is returned and the scanner's
     
* position is unchanged. This method may block waiting for input that
     
* matches the pattern.
     
*
     
* <p>Since this method continues to search through the input looking
     
* for the specified pattern, it may buffer all of the input searching for
     
* the desired token if no line separators are present.
     
*
     
* @param pattern the pattern to scan for
     
* @return the text that matched the specified pattern
     
* @throws IllegalStateException if this scanner is closed
     
*/

    
public String findInLine(Pattern pattern) {
        
ensureOpen();
        
if (pattern == null)
            
throw new NullPointerException();
        
clearCaches();
        
// Expand buffer to include the next newline or end of input
        
int endPosition = 0;
        
saveState();
        
while (true) {
            
String token = findPatternInBuffer(separatorPattern(), 0);
            
if (token != null) {
                
endPosition = matcher.start();
                
break; // up to next newline
            
}
            
if (needInput) {
                
readInput();
            
} else {
                
endPosition = buf.limit();
                
break; // up to end of input
            
}
        
}
        
revertState();
        
int horizonForLine = endPosition - position;
        
// If there is nothing between the current pos and the next
        
// newline simply return null, invoking findWithinHorizon
        
// with "horizon=0" will scan beyond the line bound.
        
if (horizonForLine == 0)
            
return null;
        
// Search for the pattern
        
return findWithinHorizon(pattern, horizonForLine);
    
}

    
/**
     
* Attempts to find the next occurrence of a pattern constructed from the
     
* specified string, ignoring delimiters.
     
*
     
* <p>An invocation of this method of the form
     
* <tt>findWithinHorizon(pattern)</tt> behaves in exactly the same way as
     
* the invocation
     
* <tt>findWithinHorizon(Pattern.compile(pattern, horizon))</tt>.
     
*
     
* @param pattern a string specifying the pattern to search for
     
* @param horizon the search horizon
     
* @return the text that matched the specified pattern
     
* @throws IllegalStateException if this scanner is closed
     
* @throws IllegalArgumentException if horizon is negative
     
*/

    
public String findWithinHorizon(String pattern, int horizon) {
        
return findWithinHorizon(patternCache.forName(pattern), horizon);
    
}

    
/**
     
* Attempts to find the next occurrence of the specified pattern.
     
*
     
* <p>This method searches through the input up to the specified
     
* search horizon, ignoring delimiters. If the pattern is found the
     
* scanner advances past the input that matched and returns the string
     
* that matched the pattern. If no such pattern is detected then the
     
* null is returned and the scanner's position remains unchanged. This
     
* method may block waiting for input that matches the pattern.
     
*
     
* <p>A scanner will never search more than <code>horizon</code> code
     
* points beyond its current position. Note that a match may be clipped
     
* by the horizon; that is, an arbitrary match result may have been
     
* different if the horizon had been larger. The scanner treats the
     
* horizon as a transparent, non-anchoring bound (see {@link
     
* Matcher#useTransparentBounds} and {@link Matcher#useAnchoringBounds}).
     
*
     
* <p>If horizon is <code>0</code>, then the horizon is ignored and
     
* this method continues to search through the input looking for the
     
* specified pattern without bound. In this case it may buffer all of
     
* the input searching for the pattern.
     
*
     
* <p>If horizon is negative, then an IllegalArgumentException is
     
* thrown.
     
*
     
* @param pattern the pattern to scan for
     
* @param horizon the search horizon
     
* @return the text that matched the specified pattern
     
* @throws IllegalStateException if this scanner is closed
     
* @throws IllegalArgumentException if horizon is negative
     
*/

    
public String findWithinHorizon(Pattern pattern, int horizon) {
        
ensureOpen();
        
if (pattern == null)
            
throw new NullPointerException();
        
if (horizon < 0)
            
throw new IllegalArgumentException("horizon < 0");
        
clearCaches();

        
// Search for the pattern
        
while (true) {
            
String token = findPatternInBuffer(pattern, horizon);
            
if (token != null) {
                
matchValid = true;
                
return token;
            
}
            
if (needInput)
                
readInput();
            
else
                
break
; // up to end of input
        
}
        
return null;
    
}

    
/**
     
* Skips input that matches the specified pattern, ignoring delimiters.
     
* This method will skip input if an anchored match of the specified
     
* pattern succeeds.
     
*
     
* <p>If a match to the specified pattern is not found at the
     
* current position, then no input is skipped and a
     
* <tt>NoSuchElementException</tt> is thrown.
     
*
     
* <p>Since this method seeks to match the specified pattern starting at
     
* the scanner's current position, patterns that can match a lot of
     
* input (".*", for example) may cause the scanner to buffer a large
     
* amount of input.
     
*
     
* <p>Note that it is possible to skip something without risking a
     
* <code>NoSuchElementException</code> by using a pattern that can
     
* match nothing, e.g., <code>sc.skip("[ \t]*")</code>.
     
*
     
* @param pattern a string specifying the pattern to skip over
     
* @return this scanner
     
* @throws NoSuchElementException if the specified pattern is not found
     
* @throws IllegalStateException if this scanner is closed
     
*/

    
public Scanner skip(Pattern pattern) {
        
ensureOpen();
        
if (pattern == null)
            
throw new NullPointerException();
        
clearCaches();

        
// Search for the pattern
        
while (true) {
            
String token = matchPatternInBuffer(pattern);
            
if (token != null) {
                
matchValid = true;
                
position = matcher.end();
                
return this;
            
}
            
if (needInput)
                
readInput();
            
else
                
throw new
NoSuchElementException();
        
}
    
}

    
/**
     
* Skips input that matches a pattern constructed from the specified
     
* string.
     
*
     
* <p> An invocation of this method of the form <tt>skip(pattern)</tt>
     
* behaves in exactly the same way as the invocation
     
* <tt>skip(Pattern.compile(pattern))</tt>.
     
*
     
* @param pattern a string specifying the pattern to skip over
     
* @return this scanner
     
* @throws IllegalStateException if this scanner is closed
     
*/

    
public Scanner skip(String pattern) {
        
return skip(patternCache.forName(pattern));
    
}

    
// Convenience methods for scanning primitives

    
/**
     
* Returns true if the next token in this scanner's input can be
     
* interpreted as a boolean value using a case insensitive pattern
     
* created from the string "true|false".
  
The scanner does not
     
* advance past the input that matched.
     
*
     
* @return true if and only if this scanner's next token is a valid
     
*
         
boolean value
     
* @throws IllegalStateException if this scanner is closed
     
*/

    
public boolean hasNextBoolean()
  
{
        
return hasNext(boolPattern());
    
}

    
/**
     
* Scans the next token of the input into a boolean value and returns
     
* that value. This method will throw <code>InputMismatchException</code>
     
* if the next token cannot be translated into a valid boolean value.
     
* If the match is successful, the scanner advances past the input that
     
* matched.
     
*
     
* @return the boolean scanned from the input
     
* @throws InputMismatchException if the next token is not a valid boolean
     
* @throws NoSuchElementException if input is exhausted
     
* @throws IllegalStateException if this scanner is closed
     
*/

    
public boolean nextBoolean()
  
{
        
clearCaches();
        
return Boolean.parseBoolean(next(boolPattern()));
    
}

    
/**
     
* Returns true if the next token in this scanner's input can be
     
* interpreted as a byte value in the default radix using the
     
* {@link #nextByte} method. The scanner does not advance past any input.
     
*
     
* @return true if and only if this scanner's next token is a valid
     
*
         
byte value
     
* @throws IllegalStateException if this scanner is closed
     
*/

    
public boolean hasNextByte() {
        
return hasNextByte(defaultRadix);
    
}

    
/**
     
* Returns true if the next token in this scanner's input can be
     
* interpreted as a byte value in the specified radix using the
     
* {@link #nextByte} method. The scanner does not advance past any input.
     
*
     
* @param radix the radix used to interpret the token as a byte value
     
* @return true if and only if this scanner's next token is a valid
     
*
         
byte value
     
* @throws IllegalStateException if this scanner is closed
     
*/

    
public boolean hasNextByte(int radix) {
        
setRadix(radix);
        
boolean result = hasNext(integerPattern());
        
if (result) { // Cache it
            
try {
                
String s = (matcher.group(SIMPLE_GROUP_INDEX) == null) ?
                    
processIntegerToken(hasNextResult) :
                    
hasNextResult;
                
typeCache = Byte.parseByte(s, radix);
            
} catch (NumberFormatException nfe) {
                
result = false;
            
}
        
}
        
return result;
    
}

    
/**
     
* Scans the next token of the input as a <tt>byte</tt>.
     
*
     
* <p> An invocation of this method of the form
     
* <tt>nextByte()</tt> behaves in exactly the same way as the
     
* invocation <tt>nextByte(radix)</tt>, where <code>radix</code>
     
* is the default radix of this scanner.
     
*
     
* @return the <tt>byte</tt> scanned from the input
     
* @throws InputMismatchException
     
*
         
if the next token does not match the <i>Integer</i>
     
*
         
regular expression, or is out of range
     
* @throws NoSuchElementException if input is exhausted
     
* @throws IllegalStateException if this scanner is closed
     
*/

    
public byte nextByte() {
         
return nextByte(defaultRadix);
    
}

    
/**
     
* Scans the next token of the input as a <tt>byte</tt>.
     
* This method will throw <code>InputMismatchException</code>
     
* if the next token cannot be translated into a valid byte value as
     
* described below. If the translation is successful, the scanner advances
     
* past the input that matched.
     
*
     
* <p> If the next token matches the <a
     
* href="#Integer-regex"><i>Integer</i></a> regular expression defined
     
* above then the token is converted into a <tt>byte</tt> value as if by
     
* removing all locale specific prefixes, group separators, and locale
     
* specific suffixes, then mapping non-ASCII digits into ASCII
     
* digits via {@link Character#digit Character.digit}, prepending a
     
* negative sign (-) if the locale specific negative prefixes and suffixes
     
* were present, and passing the resulting string to
     
* {@link Byte#parseByte(String, int) Byte.parseByte} with the
     
* specified radix.
     
*
     
* @param radix the radix used to interpret the token as a byte value
     
* @return the <tt>byte</tt> scanned from the input
     
* @throws InputMismatchException
     
*
         
if the next token does not match the <i>Integer</i>
     
*
         
regular expression, or is out of range
     
* @throws NoSuchElementException if input is exhausted
     
* @throws IllegalStateException if this scanner is closed
     
*/

    
public byte nextByte(int radix) {
        
// Check cached result
        
if ((typeCache != null) && (typeCache instanceof Byte)
            
&& this.radix == radix) {
            
byte val = ((Byte)typeCache).byteValue();
            
useTypeCache();
            
return val;
        
}
        
setRadix(radix);
        
clearCaches();
        
// Search for next byte
        
try {
            
String s = next(integerPattern());
            
if (matcher.group(SIMPLE_GROUP_INDEX) == null)
                
s = processIntegerToken(s);
            
return Byte.parseByte(s, radix);
        
} catch (NumberFormatException nfe) {
            
position = matcher.start(); // don't skip bad token
            
throw new InputMismatchException(nfe.getMessage());
        
}
    
}

    
/**
     
* Returns true if the next token in this scanner's input can be
     
* interpreted as a short value in the default radix using the
     
* {@link #nextShort} method. The scanner does not advance past any input.
     
*
     
* @return true if and only if this scanner's next token is a valid
     
*
         
short value in the default radix
     
* @throws IllegalStateException if this scanner is closed
     
*/

    
public boolean hasNextShort() {
        
return hasNextShort(defaultRadix);
    
}

    
/**
     
* Returns true if the next token in this scanner's input can be
     
* interpreted as a short value in the specified radix using the
     
* {@link #nextShort} method. The scanner does not advance past any input.
     
*
     
* @param radix the radix used to interpret the token as a short value
     
* @return true if and only if this scanner's next token is a valid
     
*
         
short value in the specified radix
     
* @throws IllegalStateException if this scanner is closed
     
*/

    
public boolean hasNextShort(int radix) {
        
setRadix(radix);
        
boolean result = hasNext(integerPattern());
        
if (result) { // Cache it
            
try {
                
String s = (matcher.group(SIMPLE_GROUP_INDEX) == null) ?
                    
processIntegerToken(hasNextResult) :
                    
hasNextResult;
                
typeCache = Short.parseShort(s, radix);
            
} catch (NumberFormatException nfe) {
                
result = false;
            
}
        
}
        
return result;
    
}

    
/**
     
* Scans the next token of the input as a <tt>short</tt>.
     
*
     
* <p> An invocation of this method of the form
     
* <tt>nextShort()</tt> behaves in exactly the same way as the
     
* invocation <tt>nextShort(radix)</tt>, where <code>radix</code>
     
* is the default radix of this scanner.
     
*
     
* @return the <tt>short</tt> scanned from the input
     
* @throws InputMismatchException
     
*
         
if the next token does not match the <i>Integer</i>
     
*
         
regular expression, or is out of range
     
* @throws NoSuchElementException if input is exhausted
     
* @throws IllegalStateException if this scanner is closed
     
*/

    
public short nextShort() {
        
return nextShort(defaultRadix);
    
}

    
/**
     
* Scans the next token of the input as a <tt>short</tt>.
     
* This method will throw <code>InputMismatchException</code>
     
* if the next token cannot be translated into a valid short value as
     
* described below. If the translation is successful, the scanner advances
     
* past the input that matched.
     
*
     
* <p> If the next token matches the <a
     
* href="#Integer-regex"><i>Integer</i></a> regular expression defined
     
* above then the token is converted into a <tt>short</tt> value as if by
     
* removing all locale specific prefixes, group separators, and locale
     
* specific suffixes, then mapping non-ASCII digits into ASCII
     
* digits via {@link Character#digit Character.digit}, prepending a
     
* negative sign (-) if the locale specific negative prefixes and suffixes
     
* were present, and passing the resulting string to
     
* {@link Short#parseShort(String, int) Short.parseShort} with the
     
* specified radix.
     
*
     
* @param radix the radix used to interpret the token as a short value
     
* @return the <tt>short</tt> scanned from the input
     
* @throws InputMismatchException
     
*
         
if the next token does not match the <i>Integer</i>
     
*
         
regular expression, or is out of range
     
* @throws NoSuchElementException if input is exhausted
     
* @throws IllegalStateException if this scanner is closed
     
*/

    
public short nextShort(int radix) {
        
// Check cached result
        
if ((typeCache != null) && (typeCache instanceof Short)
            
&& this.radix == radix) {
            
short val = ((Short)typeCache).shortValue();
            
useTypeCache();
            
return val;
        
}
        
setRadix(radix);
        
clearCaches();
        
// Search for next short
        
try {
            
String s = next(integerPattern());
            
if (matcher.group(SIMPLE_GROUP_INDEX) == null)
                
s = processIntegerToken(s);
            
return Short.parseShort(s, radix);
        
} catch (NumberFormatException nfe) {
            
position = matcher.start(); // don't skip bad token
            
throw new InputMismatchException(nfe.getMessage());
        
}
    
}

    
/**
     
* Returns true if the next token in this scanner's input can be
     
* interpreted as an int value in the default radix using the
     
* {@link #nextInt} method. The scanner does not advance past any input.
     
*
     
* @return true if and only if this scanner's next token is a valid
     
*
         
int value
     
* @throws IllegalStateException if this scanner is closed
     
*/

    
public boolean hasNextInt() {
        
return hasNextInt(defaultRadix);
    
}

    
/**
     
* Returns true if the next token in this scanner's input can be
     
* interpreted as an int value in the specified radix using the
     
* {@link #nextInt} method. The scanner does not advance past any input.
     
*
     
* @param radix the radix used to interpret the token as an int value
     
* @return true if and only if this scanner's next token is a valid
     
*
         
int value
     
* @throws IllegalStateException if this scanner is closed
     
*/

    
public boolean hasNextInt(int radix) {
        
setRadix(radix);
        
boolean result = hasNext(integerPattern());
        
if (result) { // Cache it
            
try {
                
String s = (matcher.group(SIMPLE_GROUP_INDEX) == null) ?
                    
processIntegerToken(hasNextResult) :
                    
hasNextResult;
                
typeCache = Integer.parseInt(s, radix);
            
} catch (NumberFormatException nfe) {
                
result = false;
            
}
        
}
        
return result;
    
}

    
/**
     
* The integer token must be stripped of prefixes, group separators,
     
* and suffixes, non ascii digits must be converted into ascii digits
     
* before parse will accept it.
     
*/

    
private String processIntegerToken(String token) {
        
String result = token.replaceAll(""+groupSeparator, "");
        
boolean isNegative = false;
        
int preLen = negativePrefix.length();
        
if ((preLen > 0) && result.startsWith(negativePrefix)) {
            
isNegative = true;
            
result = result.substring(preLen);
        
}
        
int sufLen = negativeSuffix.length();
        
if ((sufLen > 0) && result.endsWith(negativeSuffix)) {
            
isNegative = true;
            
result = result.substring(result.length() - sufLen,
                                      
result.length());
        
}
        
if (isNegative)
            
result = "-" + result;
        
return result;
    
}

    
/**
     
* Scans the next token of the input as an <tt>int</tt>.
     
*
     
* <p> An invocation of this method of the form
     
* <tt>nextInt()</tt> behaves in exactly the same way as the
     
* invocation <tt>nextInt(radix)</tt>, where <code>radix</code>
     
* is the default radix of this scanner.
     
*
     
* @return the <tt>int</tt> scanned from the input
     
* @throws InputMismatchException
     
*
         
if the next token does not match the <i>Integer</i>
     
*
         
regular expression, or is out of range
     
* @throws NoSuchElementException if input is exhausted
     
* @throws IllegalStateException if this scanner is closed
     
*/

    
public int nextInt() {
        
return nextInt(defaultRadix);
    
}

    
/**
     
* Scans the next token of the input as an <tt>int</tt>.
     
* This method will throw <code>InputMismatchException</code>
     
* if the next token cannot be translated into a valid int value as
     
* described below. If the translation is successful, the scanner advances
     
* past the input that matched.
     
*
     
* <p> If the next token matches the <a
     
* href="#Integer-regex"><i>Integer</i></a> regular expression defined
     
* above then the token is converted into an <tt>int</tt> value as if by
     
* removing all locale specific prefixes, group separators, and locale
     
* specific suffixes, then mapping non-ASCII digits into ASCII
     
* digits via {@link Character#digit Character.digit}, prepending a
     
* negative sign (-) if the locale specific negative prefixes and suffixes
     
* were present, and passing the resulting string to
     
* {@link Integer#parseInt(String, int) Integer.parseInt} with the
     
* specified radix.
     
*
     
* @param radix the radix used to interpret the token as an int value
     
* @return the <tt>int</tt> scanned from the input
     
* @throws InputMismatchException
     
*
         
if the next token does not match the <i>Integer</i>
     
*
         
regular expression, or is out of range
     
* @throws NoSuchElementException if input is exhausted
     
* @throws IllegalStateException if this scanner is closed
     
*/

    
public int nextInt(int radix) {
        
// Check cached result
        
if ((typeCache != null) && (typeCache instanceof Integer)
            
&& this.radix == radix) {
            
int val = ((Integer)typeCache).intValue();
            
useTypeCache();
            
return val;
        
}
        
setRadix(radix);
        
clearCaches();
        
// Search for next int
        
try {
            
String s = next(integerPattern());
            
if (matcher.group(SIMPLE_GROUP_INDEX) == null)
                
s = processIntegerToken(s);
            
return Integer.parseInt(s, radix);
        
} catch (NumberFormatException nfe) {
            
position = matcher.start(); // don't skip bad token
            
throw new InputMismatchException(nfe.getMessage());
        
}
    
}

    
/**
     
* Returns true if the next token in this scanner's input can be
     
* interpreted as a long value in the default radix using the
     
* {@link #nextLong} method. The scanner does not advance past any input.
     
*
     
* @return true if and only if this scanner's next token is a valid
     
*
         
long value
     
* @throws IllegalStateException if this scanner is closed
     
*/

    
public boolean hasNextLong() {
        
return hasNextLong(defaultRadix);
    
}

    
/**
     
* Returns true if the next token in this scanner's input can be
     
* interpreted as a long value in the specified radix using the
     
* {@link #nextLong} method. The scanner does not advance past any input.
     
*
     
* @param radix the radix used to interpret the token as a long value
     
* @return true if and only if this scanner's next token is a valid
     
*
         
long value
     
* @throws IllegalStateException if this scanner is closed
     
*/

    
public boolean hasNextLong(int radix) {
        
setRadix(radix);
        
boolean result = hasNext(integerPattern());
        
if (result) { // Cache it
            
try {
                
String s = (matcher.group(SIMPLE_GROUP_INDEX) == null) ?
                    
processIntegerToken(hasNextResult) :
                    
hasNextResult;
                
typeCache = Long.parseLong(s, radix);
            
} catch (NumberFormatException nfe) {
                
result = false;
            
}
        
}
        
return result;
    
}

    
/**
     
* Scans the next token of the input as a <tt>long</tt>.
     
*
     
* <p> An invocation of this method of the form
     
* <tt>nextLong()</tt> behaves in exactly the same way as the
     
* invocation <tt>nextLong(radix)</tt>, where <code>radix</code>
     
* is the default radix of this scanner.
     
*
     
* @return the <tt>long</tt> scanned from the input
     
* @throws InputMismatchException
     
*
         
if the next token does not match the <i>Integer</i>
     
*
         
regular expression, or is out of range
     
* @throws NoSuchElementException if input is exhausted
     
* @throws IllegalStateException if this scanner is closed
     
*/

    
public long nextLong() {
        
return nextLong(defaultRadix);
    
}

    
/**
     
* Scans the next token of the input as a <tt>long</tt>.
     
* This method will throw <code>InputMismatchException</code>
     
* if the next token cannot be translated into a valid long value as
     
* described below. If the translation is successful, the scanner advances
     
* past the input that matched.
     
*
     
* <p> If the next token matches the <a
     
* href="#Integer-regex"><i>Integer</i></a> regular expression defined
     
* above then the token is converted into a <tt>long</tt> value as if by
     
* removing all locale specific prefixes, group separators, and locale
     
* specific suffixes, then mapping non-ASCII digits into ASCII
     
* digits via {@link Character#digit Character.digit}, prepending a
     
* negative sign (-) if the locale specific negative prefixes and suffixes
     
* were present, and passing the resulting string to
     
* {@link Long#parseLong(String, int) Long.parseLong} with the
     
* specified radix.
     
*
     
* @param radix the radix used to interpret the token as an int value
     
* @return the <tt>long</tt> scanned from the input
     
* @throws InputMismatchException
     
*
         
if the next token does not match the <i>Integer</i>
     
*
         
regular expression, or is out of range
     
* @throws NoSuchElementException if input is exhausted
     
* @throws IllegalStateException if this scanner is closed
     
*/

    
public long nextLong(int radix) {
        
// Check cached result
        
if ((typeCache != null) && (typeCache instanceof Long)
            
&& this.radix == radix) {
            
long val = ((Long)typeCache).longValue();
            
useTypeCache();
            
return val;
        
}
        
setRadix(radix);
        
clearCaches();
        
try {
            
String s = next(integerPattern());
            
if (matcher.group(SIMPLE_GROUP_INDEX) == null)
                
s = processIntegerToken(s);
            
return Long.parseLong(s, radix);
        
} catch (NumberFormatException nfe) {
            
position = matcher.start(); // don't skip bad token
            
throw new InputMismatchException(nfe.getMessage());
        
}
    
}

    
/**
     
* The float token must be stripped of prefixes, group separators,
     
* and suffixes, non ascii digits must be converted into ascii digits
     
* before parseFloat will accept it.
     
*
     
* If there are non-ascii digits in the token these digits must
     
* be processed before the token is passed to parseFloat.
     
*/

    
private String processFloatToken(String token) {
        
String result = token.replaceAll(groupSeparator, "");
        
if (!decimalSeparator.equals("\\."))
            
result = result.replaceAll(decimalSeparator, ".");
        
boolean isNegative = false;
        
int preLen = negativePrefix.length();
        
if ((preLen > 0) && result.startsWith(negativePrefix)) {
            
isNegative = true;
            
result = result.substring(preLen);
        
}
        
int sufLen = negativeSuffix.length();
        
if ((sufLen > 0) && result.endsWith(negativeSuffix)) {
            
isNegative = true;
            
result = result.substring(result.length() - sufLen,
                                      
result.length());
        
}
        
if (result.equals(nanString))
            
result = "NaN";
        
if (result.equals(infinityString))
            
result = "Infinity";
        
if (isNegative)
            
result = "-" + result;

        
// Translate non-ASCII digits
        
Matcher m = NON_ASCII_DIGIT.matcher(result);
        
if (m.find()) {
            
StringBuilder inASCII = new StringBuilder();
            
for (int i=0; i<result.length(); i++) {
                
char nextChar = result.charAt(i);
                
if (Character.isDigit(nextChar)) {
                    
int d = Character.digit(nextChar, 10);
                    
if (d != -1)
                        
inASCII.append(d);
                    
else
                        
inASCII.append(nextChar);
                
} else {
                    
inASCII.append(nextChar);
                
}
            
}
            
result = inASCII.toString();
        
}

        
return result;
    
}

    
/**
     
* Returns true if the next token in this scanner's input can be
     
* interpreted as a float value using the {@link #nextFloat}
     
* method. The scanner does not advance past any input.
     
*
     
* @return true if and only if this scanner's next token is a valid
     
*
         
float value
     
* @throws IllegalStateException if this scanner is closed
     
*/

    
public boolean hasNextFloat() {
        
setRadix(10);
        
boolean result = hasNext(floatPattern());
        
if (result) { // Cache it
            
try {
                
String s = processFloatToken(hasNextResult);
                
typeCache = Float.valueOf(Float.parseFloat(s));
            
} catch (NumberFormatException nfe) {
                
result = false;
            
}
        
}
        
return result;
    
}

    
/**
     
* Scans the next token of the input as a <tt>float</tt>.
     
* This method will throw <code>InputMismatchException</code>
     
* if the next token cannot be translated into a valid float value as
     
* described below. If the translation is successful, the scanner advances
     
* past the input that matched.
     
*
     
* <p> If the next token matches the <a
     
* href="#Float-regex"><i>Float</i></a> regular expression defined above
     
* then the token is converted into a <tt>float</tt> value as if by
     
* removing all locale specific prefixes, group separators, and locale
     
* specific suffixes, then mapping non-ASCII digits into ASCII
     
* digits via {@link Character#digit Character.digit}, prepending a
     
* negative sign (-) if the locale specific negative prefixes and suffixes
     
* were present, and passing the resulting string to
     
* {@link Float#parseFloat Float.parseFloat}. If the token matches
     
* the localized NaN or infinity strings, then either "Nan" or "Infinity"
     
* is passed to {@link Float#parseFloat(String) Float.parseFloat} as
     
* appropriate.
     
*
     
* @return the <tt>float</tt> scanned from the input
     
* @throws InputMismatchException
     
*
         
if the next token does not match the <i>Float</i>
     
*
         
regular expression, or is out of range
     
* @throws NoSuchElementException if input is exhausted
     
* @throws IllegalStateException if this scanner is closed
     
*/

    
public float nextFloat() {
        
// Check cached result
        
if ((typeCache != null) && (typeCache instanceof Float)) {
            
float val = ((Float)typeCache).floatValue();
            
useTypeCache();
            
return val;
        
}
        
setRadix(10);
        
clearCaches();
        
try {
            
return Float.parseFloat(processFloatToken(next(floatPattern())));
        
} catch (NumberFormatException nfe) {
            
position = matcher.start(); // don't skip bad token
            
throw new InputMismatchException(nfe.getMessage());
        
}
    
}

    
/**
     
* Returns true if the next token in this scanner's input can be
     
* interpreted as a double value using the {@link #nextDouble}
     
* method. The scanner does not advance past any input.
     
*
     
* @return true if and only if this scanner's next token is a valid
     
*
         
double value
     
* @throws IllegalStateException if this scanner is closed
     
*/

    
public boolean hasNextDouble() {
        
setRadix(10);
        
boolean result = hasNext(floatPattern());
        
if (result) { // Cache it
            
try {
                
String s = processFloatToken(hasNextResult);
                
typeCache = Double.valueOf(Double.parseDouble(s));
            
} catch (NumberFormatException nfe) {
                
result = false;
            
}
        
}
        
return result;
    
}

    
/**
     
* Scans the next token of the input as a <tt>double</tt>.
     
* This method will throw <code>InputMismatchException</code>
     
* if the next token cannot be translated into a valid double value.
     
* If the translation is successful, the scanner advances past the input
     
* that matched.
     
*
     
* <p> If the next token matches the <a
     
* href="#Float-regex"><i>Float</i></a> regular expression defined above
     
* then the token is converted into a <tt>double</tt> value as if by
     
* removing all locale specific prefixes, group separators, and locale
     
* specific suffixes, then mapping non-ASCII digits into ASCII
     
* digits via {@link Character#digit Character.digit}, prepending a
     
* negative sign (-) if the locale specific negative prefixes and suffixes
     
* were present, and passing the resulting string to
     
* {@link Double#parseDouble Double.parseDouble}. If the token matches
     
* the localized NaN or infinity strings, then either "Nan" or "Infinity"
     
* is passed to {@link Double#parseDouble(String) Double.parseDouble} as
     
* appropriate.
     
*
     
* @return the <tt>double</tt> scanned from the input
     
* @throws InputMismatchException
     
*
         
if the next token does not match the <i>Float</i>
     
*
         
regular expression, or is out of range
     
* @throws NoSuchElementException if the input is exhausted
     
* @throws IllegalStateException if this scanner is closed
     
*/

    
public double nextDouble() {
        
// Check cached result
        
if ((typeCache != null) && (typeCache instanceof Double)) {
            
double val = ((Double)typeCache).doubleValue();
            
useTypeCache();
            
return val;
        
}
        
setRadix(10);
        
clearCaches();
        
// Search for next float
        
try {
            
return Double.parseDouble(processFloatToken(next(floatPattern())));
        
} catch (NumberFormatException nfe) {
            
position = matcher.start(); // don't skip bad token
            
throw new InputMismatchException(nfe.getMessage());
        
}
    
}

    
// Convenience methods for scanning multi precision numbers

    
/**
     
* Returns true if the next token in this scanner's input can be
     
* interpreted as a <code>BigInteger</code> in the default radix using the
     
* {@link #nextBigInteger} method. The scanner does not advance past any
     
* input.
     
*
     
* @return true if and only if this scanner's next token is a valid
     
*
         
<code>BigInteger</code>
     
* @throws IllegalStateException if this scanner is closed
     
*/

    
public boolean hasNextBigInteger() {
        
return hasNextBigInteger(defaultRadix);
    
}

    
/**
     
* Returns true if the next token in this scanner's input can be
     
* interpreted as a <code>BigInteger</code> in the specified radix using
     
* the {@link #nextBigInteger} method. The scanner does not advance past
     
* any input.
     
*
     
* @param radix the radix used to interpret the token as an integer
     
* @return true if and only if this scanner's next token is a valid
     
*
         
<code>BigInteger</code>
     
* @throws IllegalStateException if this scanner is closed
     
*/

    
public boolean hasNextBigInteger(int radix) {
        
setRadix(radix);
        
boolean result = hasNext(integerPattern());
        
if (result) { // Cache it
            
try {
                
String s = (matcher.group(SIMPLE_GROUP_INDEX) == null) ?
                    
processIntegerToken(hasNextResult) :
                    
hasNextResult;
                
typeCache = new BigInteger(s, radix);
            
} catch (NumberFormatException nfe) {
                
result = false;
            
}
        
}
        
return result;
    
}

    
/**
     
* Scans the next token of the input as a {@link java.math.BigInteger
     
* BigInteger}.
     
*
     
* <p> An invocation of this method of the form
     
* <tt>nextBigInteger()</tt> behaves in exactly the same way as the
     
* invocation <tt>nextBigInteger(radix)</tt>, where <code>radix</code>
     
* is the default radix of this scanner.
     
*
     
* @return the <tt>BigInteger</tt> scanned from the input
     
* @throws InputMismatchException
     
*
         
if the next token does not match the <i>Integer</i>
     
*
         
regular expression, or is out of range
     
* @throws NoSuchElementException if the input is exhausted
     
* @throws IllegalStateException if this scanner is closed
     
*/

    
public BigInteger nextBigInteger() {
        
return nextBigInteger(defaultRadix);
    
}

    
/**
     
* Scans the next token of the input as a {@link java.math.BigInteger
     
* BigInteger}.
     
*
     
* <p> If the next token matches the <a
     
* href="#Integer-regex"><i>Integer</i></a> regular expression defined
     
* above then the token is converted into a <tt>BigInteger</tt> value as if
     
* by removing all group separators, mapping non-ASCII digits into ASCII
     
* digits via the {@link Character#digit Character.digit}, and passing the
     
* resulting string to the {@link
     
* java.math.BigInteger#BigInteger(java.lang.String)
     
* BigInteger(String, int)} constructor with the specified radix.
     
*
     
* @param radix the radix used to interpret the token
     
* @return the <tt>BigInteger</tt> scanned from the input
     
* @throws InputMismatchException
     
*
         
if the next token does not match the <i>Integer</i>
     
*
         
regular expression, or is out of range
     
* @throws NoSuchElementException if the input is exhausted
     
* @throws IllegalStateException if this scanner is closed
     
*/

    
public BigInteger nextBigInteger(int radix) {
        
// Check cached result
        
if ((typeCache != null) && (typeCache instanceof BigInteger)
            
&& this.radix == radix) {
            
BigInteger val = (BigInteger)typeCache;
            
useTypeCache();
            
return val;
        
}
        
setRadix(radix);
        
clearCaches();
        
// Search for next int
        
try {
            
String s = next(integerPattern());
            
if (matcher.group(SIMPLE_GROUP_INDEX) == null)
                
s = processIntegerToken(s);
            
return new BigInteger(s, radix);
        
} catch (NumberFormatException nfe) {
            
position = matcher.start(); // don't skip bad token
            
throw new InputMismatchException(nfe.getMessage());
        
}
    
}

    
/**
     
* Returns true if the next token in this scanner's input can be
     
* interpreted as a <code>BigDecimal</code> using the
     
* {@link #nextBigDecimal} method. The scanner does not advance past any
     
* input.
     
*
     
* @return true if and only if this scanner's next token is a valid
     
*
         
<code>BigDecimal</code>
     
* @throws IllegalStateException if this scanner is closed
     
*/

    
public boolean hasNextBigDecimal() {
        
setRadix(10);
        
boolean result = hasNext(decimalPattern());
        
if (result) { // Cache it
            
try {
                
String s = processFloatToken(hasNextResult);
                
typeCache = new BigDecimal(s);
            
} catch (NumberFormatException nfe) {
                
result = false;
            
}
        
}
        
return result;
    
}

    
/**
     
* Scans the next token of the input as a {@link java.math.BigDecimal
     
* BigDecimal}.
     
*
     
* <p> If the next token matches the <a
     
* href="#Decimal-regex"><i>Decimal</i></a> regular expression defined
     
* above then the token is converted into a <tt>BigDecimal</tt> value as if
     
* by removing all group separators, mapping non-ASCII digits into ASCII
     
* digits via the {@link Character#digit Character.digit}, and passing the
     
* resulting string to the {@link
     
* java.math.BigDecimal#BigDecimal(java.lang.String) BigDecimal(String)}
     
* constructor.
     
*
     
* @return the <tt>BigDecimal</tt> scanned from the input
     
* @throws InputMismatchException
     
*
         
if the next token does not match the <i>Decimal</i>
     
*
         
regular expression, or is out of range
     
* @throws NoSuchElementException if the input is exhausted
     
* @throws IllegalStateException if this scanner is closed
     
*/

    
public BigDecimal nextBigDecimal() {
        
// Check cached result
        
if ((typeCache != null) && (typeCache instanceof BigDecimal)) {
            
BigDecimal val = (BigDecimal)typeCache;
            
useTypeCache();
            
return val;
        
}
        
setRadix(10);
        
clearCaches();
        
// Search for next float
        
try {
            
String s = processFloatToken(next(decimalPattern()));
            
return new BigDecimal(s);
        
} catch (NumberFormatException nfe) {
            
position = matcher.start(); // don't skip bad token
            
throw new InputMismatchException(nfe.getMessage());
        
}
    
}

    
/**
     
* Resets this scanner.
     
*
     
* <p> Resetting a scanner discards all of its explicit state
     
* information which may have been changed by invocations of {@link
     
* #useDelimiter}, {@link #useLocale}, or {@link #useRadix}.
     
*
     
* <p> An invocation of this method of the form
     
* <tt>scanner.reset()</tt> behaves in exactly the same way as the
     
* invocation
     
*
     
* <blockquote><pre>{@code
     
*
   
scanner.useDelimiter("\\p{javaWhitespace}+")
     
*
          
.useLocale(Locale.getDefault(Locale.Category.FORMAT))
     
*
          
.useRadix(10);
     
* }</pre></blockquote>
     
*
     
* @return this scanner
     
*
     
* @since 1.6
     
*/

    
public Scanner reset() {
        
delimPattern = WHITESPACE_PATTERN;
        
useLocale(Locale.getDefault(Locale.Category.FORMAT));
        
useRadix(10);
        
clearCaches();
        
return this;
    
}
}