private void finishInstruction() {
		ignoreWhitespace();
		if(readAhead!=-1) {
			char read = (char) readAhead;
			if(read==';') {
				do {
					readNext();
					read = (char) readAhead;
				} while(read!='\n');
			} else if(read=='\n') {
				readNext();
			} else {
				error("expected newline found '" + read + "'");
			}
		}
	}