presto-main/src/main/java/io/prestosql/operator/scalar/StringFunctions.java/StringFunctions/codepoint
class StringFunctions:    @Description("returns Unicode code point of a single character string")
    @ScalarFunction("codepoint")
    @SqlType(StandardTypes.INTEGER)
    public static long codepoint(@SqlType("varchar(1)") Slice slice)
    {
        checkCondition(countCodePoints(slice) == 1, INVALID_FUNCTION_ARGUMENT, "Input string must be a single character string");

        return getCodePointAt(slice, 0);
    }