To manage the names assigned to Unicode character values.

§1. The following is called only on excerpts from the source where it is a fairly safe bet that a Unicode character is referred to. For example, when the player types either of these:

"[unicode 321]odz Churchyard"

"[unicode Latin capital letter L with stroke]odz Churchyard"

...then the text after the word "unicode" is parsed by <s-unicode-character>.

<s-unicode-character> ::=
    <cardinal-number-unlimited> | ==> { -, Rvalues::from_Unicode(UnicodeLiterals::max(R[1]), W) }
    <unicode-character-name>      ==> { -, Rvalues::from_Unicode(R[1], W) }

<unicode-character-name> internal {
    parse_node *p = Lexicon::retrieve(MISCELLANEOUS_MC, W);
    if ((p) && (Node::get_type(p) == PROPER_NOUN_NT)) {
        int N = Vocabulary::get_literal_number_value(
            Lexer::word(Wordings::first_wn(Node::get_text(p))));
        ==> { N, - };
        return TRUE;
    }
    ==> { fail nonterminal };
}

• This is Preform grammar, not regular C code.

§2. And here is the range check:

int UnicodeLiterals::max?Usage of UnicodeLiterals::max:
§1(int cc) {
    if ((cc < 0) || (cc >= 0x10000)) {
        StandardProblems::sentence_problem(Task::syntax_tree(), _p_(PM_UnicodeOutOfRange),
            "Inform can only handle Unicode characters in the 16-bit range",
            "from 0 to 65535.");
        return 65;
    }
    return cc;
}