In this section we compile text constants.

§1. It's a little strange to be writing, in 2012, code to handle an idiosyncratic one-off form of text called a "quotation", just to match an idiosyncratic feature of Inform 1 from 1993 which was in turn matching an idiosyncratic feature of version 4 of the Z-machine from 1985 which, in turn, existed only to serve the needs of an unusual single work of IF called "Trinity". But here we are.

typedef struct box_quotation {
    struct inter_name *function_iname;
    struct inter_name *seen_flag_iname;
    struct text_stream *content;
    int function_compiled;
    CLASS_DEFINITION
} box_quotation;

void BoxQuotations::new(value_holster *VH, wording W) {
    box_quotation *bq = CREATE(box_quotation);
    bq->function_iname = Enclosures::new_iname(BOX_QUOTATIONS_HAP, BOX_QUOTATION_FN_HL);
    bq->seen_flag_iname = Enclosures::new_iname(BOX_QUOTATIONS_HAP, BOX_FLAG_HL);
    bq->function_compiled = FALSE;
    bq->content = Str::new();
    TranscodeText::bq_from_wide_string(bq->content, Lexer::word_text(Wordings::first_wn(W)));
    if (Str::len(bq->content) == 0)
        StandardProblems::sentence_problem(Task::syntax_tree(), _p_(PM_EmptyQuotationBox),
            "a boxed quotation can't be empty",
            "though I suppose you could make it consist of just a few spaces "
            "to get a similar effect if you really needed to.");
    text_stream *desc = Str::new();
    WRITE_TO(desc, "box quotation '%W'", W);
    Sequence::queue(&BoxQuotations::compilation_agent, STORE_POINTER_box_quotation(bq), desc);
    if (VH) Emit::holster_iname(VH, bq->function_iname);
}

• The structure box_quotation is accessed in 3/uo, 5/lp and here.

§2. The box functions are then compiled in due course by the following agent (see How To Compile (in core)). The reason they weren't simply compiled earlier is that a function was already being compiled at the time, and you can't compile two functions at the same time.

The "box function", which displays the quotation, roughly translates to:

    if (flag == false) {
        flag = true;
        box "The quotation here.";
    }

and ensures that the quotation displays only once. The flag is stored as a tiny array inside the same enclosure as the box function.

void BoxQuotations::compilation_agent?Usage of BoxQuotations::compilation_agent:
§1(compilation_subtask *t) {
    box_quotation *bq = RETRIEVE_POINTER_box_quotation(t->data);
    packaging_state save = EmitArrays::begin_word(bq->seen_flag_iname, K_number);
    EmitArrays::numeric_entry(0);
    EmitArrays::numeric_entry(0);
    EmitArrays::end(save);

    save = Functions::begin(bq->function_iname);
    EmitCode::inv(IF_BIP);
    EmitCode::down();
        EmitCode::inv(EQ_BIP);
        EmitCode::down();
            EmitCode::inv(LOOKUP_BIP);
            EmitCode::down();
                EmitCode::val_iname(K_value, bq->seen_flag_iname);
                EmitCode::val_number(0);
            EmitCode::up();
            EmitCode::val_number(0);
        EmitCode::up();
        EmitCode::code();
        EmitCode::down();
            EmitCode::inv(STORE_BIP);
            EmitCode::down();
                EmitCode::reference();
                EmitCode::down();
                    EmitCode::inv(LOOKUP_BIP);
                    EmitCode::down();
                        EmitCode::val_iname(K_value, bq->seen_flag_iname);
                        EmitCode::val_number(0);
                    EmitCode::up();
                EmitCode::up();
                EmitCode::val_number(1);
            EmitCode::up();
            EmitCode::inv(BOX_BIP);
            EmitCode::down();
                EmitCode::val_text(bq->content);
            EmitCode::up();
        EmitCode::up();
    EmitCode::up();

    Functions::end(save);
}