private int hexValueOf(char c) {
		if ((c >= '0') && (c <= '9')) {
			return c - '0';
		}
		else if ((c >= 'a') && (c <= 'f')) {
			return c - 'a' + 10;
		}
		else if ((c >= 'A') && (c <= 'F')) {
			return c - 'A' + 10;
		}
		else {
			return 0;
		}
	}
Returns the value of the given hex digit character.
Ghidra/Features/Base/src/main/java/ghidra/features/base/memsearch/format/HexSearchFormat.java