public void readNumber() {
			boolean hex = false;
			int start = column - 1;
			/* special case for hex numbers */
			if (line.charAt(start) == '0' && line.charAt(column) == 'x') {
				column++;
				hex = true;
			}
			while (column < line.length()) {
				char c = line.charAt(column);
				if (!Character.isDigit(c)) {
					if (!hex)
						break;
					if ((c < 'A' || c > 'F') && (c < 'a' || c > 'f'))
						break;
				}
				column++;
			}
			value = line.substring(start, column);
		}