examples/Mini/ASCII_CharStream.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 *
 */
/* Generated By:JavaCC: Do not edit this line. ASCII_CharStream.java Version 0.7pre6 */
package Mini;

/**
 * An implementation of interface CharStream, where the stream is assumed to
 * contain only ASCII characters (without unicode processing).
 */

public final class ASCII_CharStream
{
  public static final boolean staticFlag = true;
  static int bufsize;
  static int available;
  static int tokenBegin;
  static public int bufpos = -1;
  static private int bufline[];
  static private int bufcolumn[];

  static private int column = 0;
  static private int line = 1;

  static private boolean prevCharIsCR = false;
  static private boolean prevCharIsLF = false;

  static private java.io.Reader inputStream;

  static private char[] buffer;
  static private int maxNextCharInd = 0;
  static private int inBuf = 0;

  static private void ExpandBuff(boolean wrapAround)
  {
     char[] newbuffer = new char[bufsize + 2048];
     int newbufline[] = new int[bufsize + 2048];
     int newbufcolumn[] = new int[bufsize + 2048];

     try
     {
        if (wrapAround)
        {
           System.arraycopy(buffer, tokenBegin, newbuffer, 0, bufsize - tokenBegin);
           System.arraycopy(buffer, 0, newbuffer,
                                             bufsize - tokenBegin, bufpos);
           buffer = newbuffer;

           System.arraycopy(bufline, tokenBegin, newbufline, 0, bufsize - tokenBegin);
           System.arraycopy(bufline, 0, newbufline, bufsize - tokenBegin, bufpos);
           bufline = newbufline;

           System.arraycopy(bufcolumn, tokenBegin, newbufcolumn, 0, bufsize - tokenBegin);
           System.arraycopy(bufcolumn, 0, newbufcolumn, bufsize - tokenBegin, bufpos);
           bufcolumn = newbufcolumn;

           maxNextCharInd = (bufpos += (bufsize - tokenBegin));
        }
        else
        {
           System.arraycopy(buffer, tokenBegin, newbuffer, 0, bufsize - tokenBegin);
           buffer = newbuffer;

           System.arraycopy(bufline, tokenBegin, newbufline, 0, bufsize - tokenBegin);
           bufline = newbufline;

           System.arraycopy(bufcolumn, tokenBegin, newbufcolumn, 0, bufsize - tokenBegin);
           bufcolumn = newbufcolumn;

           maxNextCharInd = (bufpos -= tokenBegin);
        }
     }
     catch (Throwable t)
     {
        throw new Error(t.getMessage());
     }


     bufsize += 2048;
     available = bufsize;
     tokenBegin = 0;
  }

  static private void FillBuff() throws java.io.IOException
  {
     if (maxNextCharInd == available)
     {
        if (available == bufsize)
        {
           if (tokenBegin > 2048)
           {
              bufpos = maxNextCharInd = 0;
              available = tokenBegin;
           }
           else if (tokenBegin < 0) {
            bufpos = maxNextCharInd = 0;
        } else {
            ExpandBuff(false);
        }
        }
        else if (available > tokenBegin) {
            available = bufsize;
        } else if ((tokenBegin - available) < 2048) {
            ExpandBuff(true);
        } else {
            available = tokenBegin;
        }
     }

     int i;
     try {
        if ((i = inputStream.read(buffer, maxNextCharInd,
                                    available - maxNextCharInd)) == -1)
        {
           inputStream.close();
           throw new java.io.IOException();
        } else {
            maxNextCharInd += i;
        }
        return;
     }
     catch(java.io.IOException e) {
        --bufpos;
        backup(0);
        if (tokenBegin == -1) {
            tokenBegin = bufpos;
        }
        throw e;
     }
  }

  static public final char BeginToken() throws java.io.IOException
  {
     tokenBegin = -1;
     char c = readChar();
     tokenBegin = bufpos;

     return c;
  }

  static private void UpdateLineColumn(char c)
  {
     column++;

     if (prevCharIsLF)
     {
        prevCharIsLF = false;
        line += (column = 1);
     }
     else if (prevCharIsCR)
     {
        prevCharIsCR = false;
        if (c == '\n')
        {
           prevCharIsLF = true;
        } else {
            line += (column = 1);
        }
     }

     switch (c)
     {
        case '\r' :
           prevCharIsCR = true;
           break;
        case '\n' :
           prevCharIsLF = true;
           break;
        case '\t' :
           column--;
           column += (8 - (column & 07));
           break;
        default :
           break;
     }

     bufline[bufpos] = line;
     bufcolumn[bufpos] = column;
  }

  static public final char readChar() throws java.io.IOException
  {
     if (inBuf > 0)
     {
        --inBuf;
        return (char)((char)0xff & buffer[(bufpos == bufsize - 1) ? (bufpos = 0) : ++bufpos]);
     }

     if (++bufpos >= maxNextCharInd) {
        FillBuff();
    }

     char c = (char)((char)0xff & buffer[bufpos]);

     UpdateLineColumn(c);
     return (c);
  }

  static public final int getEndColumn() {
     return bufcolumn[bufpos];
  }

  static public final int getEndLine() {
     return bufline[bufpos];
  }

  static public final int getBeginColumn() {
     return bufcolumn[tokenBegin];
  }

  static public final int getBeginLine() {
     return bufline[tokenBegin];
  }

  static public final void backup(int amount) {

    inBuf += amount;
    if ((bufpos -= amount) < 0) {
        bufpos += bufsize;
    }
  }

  public ASCII_CharStream(java.io.Reader dstream, int startline,
  int startcolumn, int buffersize)
  {
    if (inputStream != null) {
        throw new Error("\n   ERROR: Second call to the constructor of a static ASCII_CharStream.  You must\n" +
           "       either use ReInit() or set the JavaCC option STATIC to false\n" +
           "       during the generation of this class.");
    }
    inputStream = dstream;
    line = startline;
    column = startcolumn - 1;

    available = bufsize = buffersize;
    buffer = new char[buffersize];
    bufline = new int[buffersize];
    bufcolumn = new int[buffersize];
  }

  public ASCII_CharStream(java.io.Reader dstream, int startline,
                                                           int startcolumn)
  {
     this(dstream, startline, startcolumn, 4096);
  }
  static public void ReInit(java.io.Reader dstream, int startline,
  int startcolumn, int buffersize)
  {
    inputStream = dstream;
    line = startline;
    column = startcolumn - 1;

    if (buffer == null || buffersize != buffer.length)
    {
      available = bufsize = buffersize;
      buffer = new char[buffersize];
      bufline = new int[buffersize];
      bufcolumn = new int[buffersize];
    }
    prevCharIsLF = prevCharIsCR = false;
    tokenBegin = inBuf = maxNextCharInd = 0;
    bufpos = -1;
  }

  static public void ReInit(java.io.Reader dstream, int startline,
                                                           int startcolumn)
  {
     ReInit(dstream, startline, startcolumn, 4096);
  }
  public ASCII_CharStream(java.io.InputStream dstream, int startline,
  int startcolumn, int buffersize)
  {
     this(new java.io.InputStreamReader(dstream), startline, startcolumn, 4096);
  }

  public ASCII_CharStream(java.io.InputStream dstream, int startline,
                                                           int startcolumn)
  {
     this(dstream, startline, startcolumn, 4096);
  }

  static public void ReInit(java.io.InputStream dstream, int startline,
  int startcolumn, int buffersize)
  {
     ReInit(new java.io.InputStreamReader(dstream), startline, startcolumn, 4096);
  }
  static public void ReInit(java.io.InputStream dstream, int startline,
                                                           int startcolumn)
  {
     ReInit(dstream, startline, startcolumn, 4096);
  }
  static public final String GetImage()
  {
     if (bufpos >= tokenBegin) {
        return new String(buffer, tokenBegin, bufpos - tokenBegin + 1);
    } else {
        return new String(buffer, tokenBegin, bufsize - tokenBegin) +
                              new String(buffer, 0, bufpos + 1);
    }
  }

  static public final char[] GetSuffix(int len)
  {
     char[] ret = new char[len];

     if ((bufpos + 1) >= len) {
        System.arraycopy(buffer, bufpos - len + 1, ret, 0, len);
    } else
     {
        System.arraycopy(buffer, bufsize - (len - bufpos - 1), ret, 0,
                                                          len - bufpos - 1);
        System.arraycopy(buffer, 0, ret, len - bufpos - 1, bufpos + 1);
     }

     return ret;
  }

  static public void Done()
  {
     buffer = null;
     bufline = null;
     bufcolumn = null;
  }

  /**
   * Method to adjust line and column numbers for the start of a token.<BR>
   */
  static public void adjustBeginLineColumn(int newLine, int newCol)
  {
     int start = tokenBegin;
     int len;

     if (bufpos >= tokenBegin)
     {
        len = bufpos - tokenBegin + inBuf + 1;
     }
     else
     {
        len = bufsize - tokenBegin + bufpos + 1 + inBuf;
     }

     int i = 0, j = 0, k = 0;
     int nextColDiff = 0, columnDiff = 0;

     while (i < len &&
            bufline[j = start % bufsize] == bufline[k = ++start % bufsize])
     {
        bufline[j] = newLine;
        nextColDiff = columnDiff + bufcolumn[k] - bufcolumn[j];
        bufcolumn[j] = newCol + columnDiff;
        columnDiff = nextColDiff;
        i++;
     }

     if (i < len)
     {
        bufline[j] = newLine++;
        bufcolumn[j] = newCol + columnDiff;

        while (i++ < len)
        {
           if (bufline[j = start % bufsize] != bufline[++start % bufsize]) {
            bufline[j] = newLine++;
        } else {
            bufline[j] = newLine;
        }
        }
     }

     line = bufline[j];
     column = bufcolumn[j];
  }

}