public int parseDigits() {
		String num = "";

		if (nextChar() == '0') {
			return 0;
		}

		while (nextChar() >= '0' && nextChar() <= '9') {
			num += popChar();
		}

		return Integer.parseInt(num);
	}
Parses the following numerical digits in the mangled sting
@return the parsed integer
Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/analysis/rust/demangler/RustDemanglerV0.java