void push(Reader in) throws IOException {
  stack.push(new Integer(ln));
  stack.push(new Integer(ch));
  stack.push(this.in);
  this.in=in;
  ch=in.read();
}

void push ( Reader in ) throws IOException { stack . push ( new Integer ( ln ) ) ; stack . push ( new Integer ( ch ) ) ; stack . push ( this . in ) ; this . in = in ; ch = in . read ( ) ; }
push an entire input stream
