org.armedbear.lisp.SeekableStringWriter Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of abcl Show documentation
Common Lisp implementation running on the JVM
There is a newer version: 1.9.2
/*
 * SeekableStringWriter.java
 *
 * Copyright (C) 2016 Olof-Joachim Frahm
 * $Id$
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program 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 for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 *
 * As a special exception, the copyright holders of this library give you
 * permission to link this library with independent modules to produce an
 * executable, regardless of the license terms of these independent
 * modules, and to copy and distribute the resulting executable under
 * terms of your choice, provided that you also meet, for each linked
 * independent module, the terms and conditions of the license of that
 * module.  An independent module is a module which is not derived from
 * or based on this library.  If you modify this library, you may extend
 * this exception to your version of the library, but you are not
 * obligated to do so.  If you do not wish to do so, delete this
 * exception statement from your version.
 */

package org.armedbear.lisp;

import static org.armedbear.lisp.Lisp.*;

import java.io.Writer;
import java.text.MessageFormat;

public final class SeekableStringWriter extends Writer {
    private final StringBuffer stringBuffer;
    private int offset = 0;

    public SeekableStringWriter() {
        stringBuffer = new StringBuffer();
    }

    public SeekableStringWriter(int initialSize) {
        stringBuffer = new StringBuffer(initialSize);
    }

    public SeekableStringWriter append(char c) {
        write(c);
        return this;
    }

    public SeekableStringWriter append(CharSequence csq) {
        write(csq.toString());
        return this;
    }

    public SeekableStringWriter append(CharSequence csq, int start, int end) {
        write(csq.subSequence(start, end).toString());
        return this;
    }

    @Override
    public void write(char[] cbuf) {
        _write(cbuf, 0, cbuf.length);
    }

    @Override
    public void write(char[] cbuf, int off, int len) {
        int bufLen = cbuf.length;

        if (off < 0 || off > bufLen || len < 0 || off + len > bufLen)
            throw new IllegalArgumentException();

        _write(cbuf, off, len);
    }

    @Override
    public void write(int c) {
      try {
        if (offset == stringBuffer.length())
            stringBuffer.append((char) c);
        else
            stringBuffer.setCharAt(offset, (char) c);
        ++offset;
      } catch (IndexOutOfBoundsException e) {
        error(new JavaException(e));
      }
    }

    @Override
    public void write(String str) {
        write(str, 0, str.length());
    }

    @Override
    public void write(String str, int off, int len) {
        write(str.toCharArray(), off, len);
    }

    private void _write(char[] cbuf, int off, int len) {
        int strLen = stringBuffer.length();
        int space = strLen - offset;

        int written = Math.min(len, space);

        if (written > 0)
            stringBuffer.replace(offset, offset + written, new String(cbuf, off, written));

        if (written < len)
            stringBuffer.append(cbuf, off + written, len - written);

        offset += len;
    }

    public void seek(int offset) {
        if (offset < 0 || offset > stringBuffer.length())
            throw new IllegalArgumentException();
        this.offset = offset;
    }

    public StringBuffer getBuffer() {
        return stringBuffer;
    }

    public int getOffset() {
        return offset;
    }

    @Override
    public String toString() {
        return stringBuffer.toString();
    }

    @Override
    public void close() {}

    @Override
    public void flush() {}

  public String toStringAndClear() {
    String result = stringBuffer.toString();
    stringBuffer.delete(0, stringBuffer.length());
    offset = 0;
    return result;
  }
    
}