bigloo.input_procedure_port.rgc_fill_buffer C# (CSharp) Method

        public override bool rgc_fill_buffer()
        {
            int bufsize = this.bufsiz;
              int bufpose = this.bufpos;
              int matchstart = this.matchstart;
              Object value = foreign.eval_funcall_0( _in );
              int value_len = 0;

              if (value is byte[]) {
            value_len = ((byte[])value).Length;
              } else {
            if (value is bchar ) {
              value_len = 1;
            } else {
              if (foreign.EOF_OBJECTP( value ) ||
            (value == bigloo.foreign.BFALSE)) {
             eof = true;
             return false;
              } else {
            foreign.fail( "input-procedure-port",
              "Procedure result must be a string, or a char, or #f, or the eof-object",
              this );
              }
            }
              }

              int already_used = (bufpose - matchstart);

              // first let's see if the buffer is big enough
              rgc_enlarge_buffer_size(value_len + already_used);

              bufsize = this.bufsiz;

              // do we need to shift?
              if ((bufpose + value_len) > bufsiz) {
            // we shift the buffer left
            for ( int i = 0 ; i < already_used ; ++i )
              buffer[i] = buffer[matchstart+i];

            bufpose -= matchstart;
            this.matchstart = 0;
            this.matchstop -= matchstart;
            this.forward -= matchstart;
            this.lastchar = buffer[matchstart-1];
              }

              // finally we insert our object
              if (value is byte[]) {
             for (int i = 0; i < value_len; i++) {
            buffer[i + bufpose - 1] = ((byte[])value)[i];
             }
             buffer[bufpose + value_len - 1] = 0;
              } else {
            if (value is bchar) {
              buffer[bufpose - 1] = ((bchar)value).value;
            }
              }

              this.bufpos = bufpose + value_len;

              return true;
        }