/* Generated by: ParserGeneratorCC: Do not edit this line. AbstractCharStream.java Version 1.1 */
   /* ParserGeneratorCCOptions:SUPPORT_CLASS_VISIBILITY_PUBLIC=true */
   package org.apache.commons.jexl3.parser;
   
   /**
    * An implementation of interface CharStream, where the stream is assumed to
    * contain only ASCII characters (without unicode processing).
    */
   
  public
  abstract class AbstractCharStream
  implements CharStream
  {
    /** Default buffer size if nothing is specified */
    public static final int DEFAULT_BUF_SIZE = 4096;
  
    static final int hexval (final char c) throws java.io.IOException
    {
      switch (c)
      {
        case '0':
          return 0;
        case '1':
          return 1;
        case '2':
          return 2;
        case '3':
          return 3;
        case '4':
          return 4;
        case '5':
          return 5;
        case '6':
          return 6;
        case '7':
          return 7;
        case '8':
          return 8;
        case '9':
          return 9;
        case 'a':
        case 'A':
          return 10;
        case 'b':
        case 'B':
          return 11;
        case 'c':
        case 'C':
          return 12;
        case 'd':
        case 'D':
          return 13;
        case 'e':
        case 'E':
          return 14;
        case 'f':
        case 'F':
          return 15;
        default:  
          throw new java.io.IOException ("Invalid hex char '" + c + "' (=" + (int) c + ") provided!"); 
      }
    }
  
    /** Tab size for formatting. Usually in the range 1 to 8. */
    private int m_nTabSize = 1;
  
    /** Internal circular buffer */
    protected char[] buffer;
  
    /** Overall buffer size - same as buffer.length */
    protected int bufsize;
  
    /** Current read position in buffer. */
    protected int bufpos;
    
    /** The number of unoccupied buffer array positions */
    protected int available;
    
    /** The first array index (of `buffer`) that the current token starts */
    protected int tokenBegin;
  
    /** Characters in the backup/pushBack buffer */
    protected int inBuf;
    protected int maxNextCharInd;
  
    private int[] m_aBufLine;
    private int[] m_aBufColumn;
  
    // Current line number
    private int m_nLineNo;
    // Current column number
    private int m_nColumnNo;
  
    // Was the previous character a "\r" char?
    private boolean m_bPrevCharIsCR;
    // Was the previous character a "\n" char?
    private boolean m_bPrevCharIsLF;
    
    // Is line/column tracking enabled?
   private boolean m_bTrackLineColumn = true;
 
 
   /** Constructor. */
   public AbstractCharStream(final int nStartLine,
                             final int nStartColumn, 
                             final int nBufferSize)
   {
     reInit (nStartLine, nStartColumn, nBufferSize);
   }
 
   /** Reinitialise. */
   public final void reInit(final int nStartLine,
                            final int nStartColumn, 
                            final int nBufferSize)
   {
     m_nLineNo = nStartLine;
     m_nColumnNo = nStartColumn - 1;
     m_bPrevCharIsCR = false;
     m_bPrevCharIsLF = false;
     if (buffer == null || nBufferSize != buffer.length)
     {
       bufsize = nBufferSize;
       available = nBufferSize;
       buffer = new char[nBufferSize];
       m_aBufLine = new int[nBufferSize];
       m_aBufColumn = new int[nBufferSize];
     }
     maxNextCharInd = 0;
     inBuf = 0;
     tokenBegin = 0;
     bufpos = -1;
   }
 
   /**
    * Read from the underlying stream.
    * @param aBuf the buffer to be filled
    * @param nOfs The offset into the buffer. 0-based
    * @param nLen Number of chars to read.
    * @return Number of effective chars read, or -1 on error.
    */
   protected abstract int streamRead (char[] aBuf, int nOfs, int nLen) throws java.io.IOException;
   
   /**
    * Close the underlying stream.
    * @throws java.io.IOException If closing fails.
    */
   protected abstract void streamClose () throws java.io.IOException;
    
   // Override this method if you need more aggressive buffer size expansion
   protected int getBufSizeAfterExpansion ()
   {
     // Double the size by default
     return bufsize * 2;
   }
 
   protected void expandBuff (final boolean bWrapAround)
   {
     // Get the new buffer size
     final int nNewBufSize = getBufSizeAfterExpansion ();
     
     final char[] newbuffer = new char[nNewBufSize];
     final int[] newbufline = new int[nNewBufSize];
     final int[] newbufcolumn = new int[nNewBufSize];
 
     // Number of chars to be preserved
     final int nPreservedChars = bufsize - tokenBegin;
     
     if (bWrapAround)
     {
       // Move from offset "tokenBegin" to offset 0
       // arraycopy(src, srcPos, dest, destPos, length)
 
       // copy the "tail end" to the "start" (index 0) of the new buffer array 
       System.arraycopy(buffer, tokenBegin, newbuffer, 0, nPreservedChars);
       
       // copy the remaining "wrap around" content of the buffer from the start of the original buffer (starting at srcPos index 0) 
       System.arraycopy(buffer, 0, newbuffer, nPreservedChars, bufpos);
       
       // swap the new buffer in place of the old buffer
       buffer = newbuffer;
       
       System.arraycopy(m_aBufLine, tokenBegin, newbufline, 0, nPreservedChars);
       System.arraycopy(m_aBufLine, 0, newbufline, nPreservedChars, bufpos);
       m_aBufLine = newbufline;
 
       System.arraycopy(m_aBufColumn, tokenBegin, newbufcolumn, 0, nPreservedChars);
       System.arraycopy(m_aBufColumn, 0, newbufcolumn, nPreservedChars, bufpos);
       m_aBufColumn = newbufcolumn;
 
       bufpos += nPreservedChars;
       maxNextCharInd = bufpos;
     }
     else
     {
       // Move from offset "tokenBegin" to offset 0
       
       System.arraycopy(buffer, tokenBegin, newbuffer, 0, nPreservedChars);
       buffer = newbuffer;
 
       System.arraycopy(m_aBufLine, tokenBegin, newbufline, 0, nPreservedChars);
       m_aBufLine = newbufline;
 
       System.arraycopy(m_aBufColumn, tokenBegin, newbufcolumn, 0, nPreservedChars);
       m_aBufColumn = newbufcolumn;
 
       bufpos -= tokenBegin;
       maxNextCharInd = bufpos;
     }
 
     // Increase buffer size
     bufsize = nNewBufSize;
     available = nNewBufSize;
     tokenBegin = 0;
   }
 
   protected final void internalAdjustBuffSize()
   {
     final int nHalfBufferSize = bufsize / 2; 
     if (available == bufsize)
     {
       if (tokenBegin < 0)
       {
         // If this method is called from "beginToken()"
         // Just refill the buffer from the start
         bufpos = 0;
         maxNextCharInd = 0;
       }
       else
         if (tokenBegin > nHalfBufferSize)
         {
           // The token started in the second half - fill the front part 
           bufpos = 0;
           maxNextCharInd = 0;
 
           // Available bytes are > 50%
           available = tokenBegin;
         }
         else
         {
           // Token starts in the first half
           // just append to existing buffer
           expandBuff (false);
         }
     }
     else
     {
       // A token was read across array boundaries 
       if (available > tokenBegin)
       {
         available = bufsize;
       }
       else
         if ((tokenBegin - available) < nHalfBufferSize)
         {
           expandBuff (true);
         }
         else
         {
           available = tokenBegin;
         }
     }
   }
 
   protected void fillBuff() throws java.io.IOException
   {
     if (maxNextCharInd == available)
       internalAdjustBuffSize();
 
     try
     {
       // Read from underlying stream
       final int nCharsRead = streamRead (buffer, maxNextCharInd, available - maxNextCharInd);
       if (nCharsRead == -1) 
       {
         // We reached the end of the file
         streamClose ();
         
         // Caught down below and re-thrown
         throw new java.io.IOException("PGCC end of stream");
       }
       maxNextCharInd += nCharsRead;
     }
     catch (final java.io.IOException ex)
     {
       --bufpos;
       // ?What is the reason of this? Backup of 0 does nothing
       backup (0);
       if (tokenBegin == -1)
       {
         // Error occurred in "beginToken()"
         tokenBegin = bufpos;
       }
       throw ex;
     }
   }
 
   protected final void internalSetBufLineColumn (final int nLine, final int nColumn)
   {
     m_aBufLine[bufpos] = nLine;
     m_aBufColumn[bufpos] = nColumn;
   }
 
   protected final void internalUpdateLineColumn(final char c)
   {
     m_nColumnNo++;
 
     if (m_bPrevCharIsLF)
     {
       // It's a "\r\n" or "\n"
       // Start of a new line
       m_bPrevCharIsLF = false;
       m_nColumnNo = 1;
       m_nLineNo++;
     }
     else
       if (m_bPrevCharIsCR)
       {
         m_bPrevCharIsCR = false;
         if (c == '\n')
         {
           // It's a "\r\n"
           m_bPrevCharIsLF = true;
         }
         else
         {
           // It's only a "\r"
           m_nColumnNo = 1;
           m_nLineNo++;
         }
       }
 
     switch (c)
     {
       case '\r':
         m_bPrevCharIsCR = true;
         break;
       case '\n':
         m_bPrevCharIsLF = true;
         break;
       case '\t':
         m_nColumnNo--;
         m_nColumnNo += (m_nTabSize - (m_nColumnNo % m_nTabSize));
         break;
     }
 
     internalSetBufLineColumn (m_nLineNo, m_nColumnNo);
   }
 
   public char readChar() throws java.io.IOException
   {
     if (inBuf > 0)
     {
       // Something is left from last backup
       --inBuf;
 
       ++bufpos;
       if (bufpos == bufsize)
       {
         // Buffer overflow
         bufpos = 0;
       }
 
       return buffer[bufpos];
     }
 
     ++bufpos;
     if (bufpos >= maxNextCharInd)
       fillBuff();
 
     final char c = buffer[bufpos];
 
     if (m_bTrackLineColumn)
       internalUpdateLineColumn(c);
     return c;
   }
 
   public char beginToken() throws java.io.IOException
   {
     tokenBegin = -1;
     final char c = readChar();
     tokenBegin = bufpos;
     return c;
   }
 
   public int getBeginColumn ()
   {
     return m_aBufColumn[tokenBegin];
   }
 
   public int getBeginLine ()
   {
     return m_aBufLine[tokenBegin];
   }
 
   public int getEndColumn ()
   {
     return m_aBufColumn[bufpos];
   }
 
   public int getEndLine ()
   {
      return m_aBufLine[bufpos];
   }
 
   public void backup (final int nAmount)
   {
     if (nAmount > bufsize)
       throw new IllegalStateException ("Cannot back " + nAmount + " chars which is larger than the internal buffer size (" + bufsize + ")");
   
     inBuf += nAmount;
     bufpos -= nAmount;
     if (bufpos < 0)
     {
       // Buffer underflow (modulo)
       bufpos += bufsize;
     }
   }
 
   public String getImage()
   {
     if (bufpos >= tokenBegin)
     {
       // from tokenBegin to bufpos
       return new String (buffer, tokenBegin, bufpos - tokenBegin + 1);
     }
 
     // from tokenBegin to bufsize, and from 0 to bufpos
     return new String (buffer, tokenBegin, bufsize - tokenBegin) +
            new String (buffer, 0, bufpos + 1);
   }
 
   public char[] getSuffix (final int len)
   {
     char[] ret = new char[len];
     if ((bufpos + 1) >= len)
     {
       // one piece
       System.arraycopy(buffer, bufpos - len + 1, ret, 0, len);
     }
     else
     {
       // Wrap around
       final int nPart1 = len - bufpos - 1;
       System.arraycopy(buffer, bufsize - nPart1, ret, 0, nPart1);
       System.arraycopy(buffer, 0, ret, nPart1, bufpos + 1);
     }
     return ret;
   }
 
   public void done()
   {
     buffer = null;
     m_aBufLine = null;
     m_aBufColumn = null;
   }
  
   public final int getTabSize()
   { 
     return m_nTabSize;
   }
 
   public final void setTabSize (final int nTabSize)
   { 
     m_nTabSize = nTabSize;
   }
 
   /**
    * Method to adjust line and column numbers for the start of a token.
    * This is used internally to 
    */
   public final void adjustBeginLineColumn(final int nNewLine, final int newCol)
   {
     int start = tokenBegin;
     int newLine = nNewLine;
     
     int len;
     if (bufpos >= tokenBegin)
     {
       len = bufpos - tokenBegin + inBuf + 1;
     }
     else
     {
       len = bufsize - tokenBegin + bufpos + 1 + inBuf;
     }
 
     int i = 0;
     int j = 0;
     int k = 0;
     int nextColDiff = 0;
     int columnDiff = 0;
 
     // TODO disassemble meaning and split up
     while (i < len && m_aBufLine[j = start % bufsize] == m_aBufLine[k = ++start % bufsize])
     {
       m_aBufLine[j] = newLine;
       nextColDiff = columnDiff + m_aBufColumn[k] - m_aBufColumn[j];
       m_aBufColumn[j] = newCol + columnDiff;
       columnDiff = nextColDiff;
       i++;
     }
 
     if (i < len)
     {
       m_aBufLine[j] = newLine++;
       m_aBufColumn[j] = newCol + columnDiff;
 
       while (i++ < len)
       {
         // TODO disassemble meaning and split up
         if (m_aBufLine[j = start % bufsize] != m_aBufLine[++start % bufsize])
           m_aBufLine[j] = newLine++;
         else
           m_aBufLine[j] = newLine;
       }
     }
 
     m_nLineNo = m_aBufLine[j];
     m_nColumnNo = m_aBufColumn[j];
   }
   
   /**
    * @return the current line number. 0-based.
    */
   protected final int getLine ()
   { 
     return m_nLineNo;
   }
   
   /**
    * @return the current column number. 0-based.
    */
   protected final int getColumn ()
   { 
     return m_nColumnNo;
   }
   
   public final boolean isTrackLineColumn ()
   { 
     return m_bTrackLineColumn;
   }
 
   public final void setTrackLineColumn (final boolean bTrackLineColumn)
   { 
     m_bTrackLineColumn = bTrackLineColumn;
   }
 }
 /* ParserGeneratorCC - OriginalChecksum=283eac7ebcfba4d68a92326195156b9a (do not edit this line) */