@Override
	public String convertText(String text, SearchSettings oldSettings, SearchSettings newSettings) {
		SearchFormat oldFormat = oldSettings.getSearchFormat();
		if (oldFormat.getClass() == getClass()) {
			return text;
		}
		if (oldFormat.getFormatType() != SearchFormatType.STRING_TYPE) {
			ByteMatcher byteMatcher = oldFormat.parse(text, oldSettings);
			if ((byteMatcher instanceof MaskedByteSequenceByteMatcher matcher)) {
				byte[] bytes = matcher.getBytes();
				byte[] mask = matcher.getMask();
				return getMaskedInputString(bytes, mask);
			}
		}

		return isValidText(text, newSettings) ? text : "";
	}
Returns the value of the given hex digit character.
Ghidra/Features/Base/src/main/java/ghidra/features/base/memsearch/format/HexSearchFormat.java