package org.json;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.io.StringReader;

/*
Copyright (c) 2002 JSON.org

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

The Software shall be used for Good, not Evil.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
 */

/**
 * A JSONTokener takes a source string and extracts characters and tokens from
 * it. It is used by the JSONObject and JSONArray constructors to parse
 * JSON source strings.
 * @author JSON.org
 * @version 2014-05-03
 */
public class JSONTokener {
    /** current read character position on the current line. */
    private long character;
    /** flag to indicate if the end of the input has been found. */
    private boolean eof;
    /** current read index of the input. */
    private long index;
    /** current line of the input. */
    private long line;
    /** previous character read from the input. */
    private char previous;
    /** Reader for the input. */
    private final Reader reader;
    /** flag to indicate that a previous character was requested. */
    private boolean usePrevious;
    /** the number of characters read in the previous line. */
    private long characterPreviousLine;


    /**
     * Construct a JSONTokener from a Reader. The caller must close the Reader.
     *
     * @param reader     A reader.
     */
    public JSONTokener(Reader reader) {
        this.reader = reader.markSupported()
                ? reader
                        : new BufferedReader(reader);
        this.eof = false;
        this.usePrevious = false;
        this.previous = 0;
        this.index = 0;
        this.character = 1;
        this.characterPreviousLine = 0;
        this.line = 1;
    }


    /**
     * Construct a JSONTokener from an InputStream. The caller must close the input stream.
     * @param inputStream The source.
     */
    public JSONTokener(InputStream inputStream) {
        this(new InputStreamReader(inputStream));
    }


    /**
     * Construct a JSONTokener from a string.
     *
     * @param s     A source string.
     */
    public JSONTokener(String s) {
        this(new StringReader(s));
    }


    /**
     * Back up one character. This provides a sort of lookahead capability,
     * so that you can test for a digit or letter before attempting to parse
     * the next number or identifier.
     * @throws JSONException Thrown if trying to step back more than 1 step
     *  or if already at the start of the string
     */
    public void back() throws JSONException {
        if (this.usePrevious || this.index  0){
            this.character--;
        }
    }

    /**
     * Get the hex value of a character (base16).
     * @param c A character between '0' and '9' or between 'A' and 'F' or
     * between 'a' and 'f'.
     * @return  An int between 0 and 15, or -1 if c was not a hex digit.
     */
    public static int dehexchar(char c) {
        if (c >= '0' && c = 'A' && c = 'a' && c