To compile I6 material needed at runtime to enable kinds to function as they should.

• §1. Default values

§1. Default values. When we create a new variable (or other storage object) of a given kind, but never say what its value is to be, Inform tries to initialise it to the "default value" for that kind.

The following should compile a default value for \(K\), and return

• (a) TRUE if it succeeded,
• (b) FALSE if it failed (because \(K\) had no values or no default could be chosen), but no problem message has been issued about this, or
• (c) NOT_APPLICABLE if it failed and issued a specific problem message.

int DefaultValues::array_entry?Usage of DefaultValues::array_entry:
Tables - §2.1.1.1.5(kind *K, wording W, char *storage_name) {
    value_holster VH = Holsters::new(INTER_DATA_VHMODE);
    int rv = DefaultValues::to_holster(&VH, K, W, storage_name);
    inter_ti v1 = 0, v2 = 0;
    Holsters::unholster_pair(&VH, &v1, &v2);
    EmitArrays::generic_entry(v1, v2);
    return rv;
}
int DefaultValues::val?Usage of DefaultValues::val:
Kind Constructors - §11(kind *K, wording W, char *storage_name) {
    value_holster VH = Holsters::new(INTER_DATA_VHMODE);
    int rv = DefaultValues::to_holster(&VH, K, W, storage_name);
    Holsters::unholster_to_code_val(Emit::tree(), &VH);
    return rv;
}
int DefaultValues::to_holster?Usage of DefaultValues::to_holster:
Variables - §15.1
Properties - §8(value_holster *VH, kind *K,
    wording W, char *storage_name) {
    if (Kinds::eq(K, K_value))
        "Value" is too vague to be the kind of a variable1.3;
    if (Kinds::Behaviour::definite(K) == FALSE)
        This is a kind not intended for end users at all1.2;
    inter_ti v1 = 0, v2 = 0;
    DefaultValues::to_value_pair(&v1, &v2, K);
    if (v1 != 0) {
        if (Holsters::non_void_context(VH)) {
            Holsters::holster_pair(VH, v1, v2);
            return TRUE;
        }
        internal_error("thwarted on gdv inter");
    }
    if (Kinds::Behaviour::is_subkind_of_object(K))
        The kind must have no instances, or it would have worked1.1;
    return FALSE;
}

§1.1. The kind must have no instances, or it would have worked1.1 =

    if (Wordings::nonempty(W)) {
        Problems::quote_wording_as_source(1, W);
        Problems::quote_kind(2, K);
        Problems::quote_text(3, storage_name);
        StandardProblems::handmade_problem(Task::syntax_tree(), _p_(PM_EmptyKind2));
        Problems::issue_problem_segment(
            "I am unable to put any value into the %3 %1, which needs to be %2, "
            "because the world does not contain %2.");
        Problems::issue_problem_end();
    } else {
        Problems::quote_kind(2, K);
        StandardProblems::handmade_problem(Task::syntax_tree(), _p_(PM_EmptyKind));
        Problems::issue_problem_segment(
            "I am unable to find %2 to use here, because the world does not "
            "contain %2.");
        Problems::issue_problem_end();
    }
    return NOT_APPLICABLE;

• This code is used in §1.

§1.2. This is a kind not intended for end users at all1.2 =

    if (Wordings::nonempty(W)) {
        Problems::quote_wording_as_source(1, W);
        Problems::quote_kind(2, K);
        StandardProblems::handmade_problem(Task::syntax_tree(), _p_(BelievedImpossible));
        Problems::issue_problem_segment(
            "I am unable to create %1 with the kind of value '%2', "
            "because this is a kind of value which is not allowed as "
            "something to be stored in properties, variables and the "
            "like. (See the Kinds index for which kinds of value "
            "are available. The ones which aren't available are really "
            "for internal use by Inform.)");
        Problems::issue_problem_end();
    } else {
        Problems::quote_kind(1, K);
        StandardProblems::handmade_problem(Task::syntax_tree(), _p_(BelievedImpossible));
        Problems::issue_problem_segment(
            "I am unable to create a value of the kind '%1' "
            "because this is a kind of value which is not allowed as "
            "something to be stored in properties, variables and the "
            "like. (See the Kinds index for which kinds of value "
            "are available. The ones which aren't available are really "
            "for internal use by Inform.)");
        Problems::issue_problem_end();
    }
    return NOT_APPLICABLE;

• This code is used in §1.

§1.3. "Value" is too vague to be the kind of a variable1.3 =

    Problems::quote_wording_as_source(1, W);
    StandardProblems::handmade_problem(Task::syntax_tree(), _p_(BelievedImpossible));
    Problems::issue_problem_segment(
        "I am unable to start %1 off with any value, because the "
        "instructions do not tell me what kind of value it should be "
        "(a number, a time, some text perhaps?).");
    Problems::issue_problem_end();
    return NOT_APPLICABLE;

• This code is used in §1.

§2. This returns either valid I6 code for the value which is the default for \(K\), or else NULL if \(K\) has no values, or no default can be chosen.

We bend the rules and allow nothing as the default value of all kinds of objects when the source text is a roomless one used only to rerelease an old I6 story file; this effectively suppresses problem messages which the absence of rooms would otherwise result in.

void DefaultValues::to_value_pair?Usage of DefaultValues::to_value_pair:
§1
Emit - §7(inter_ti *v1, inter_ti *v2, kind *K) {
    if (K == NULL) return;

    if ((Kinds::get_construct(K) == CON_list_of) ||
        (Kinds::get_construct(K) == CON_phrase) ||
        (Kinds::get_construct(K) == CON_relation)) {
        inter_name *DV = NULL;
        runtime_kind_structure *rks = RTKindIDs::get_rks(K);
        if (rks) DV = RTKindIDs::default_value_from_rks(rks);
        if (Kinds::get_construct(K) == CON_list_of) {
            Emit::to_value_pair(v1, v2, ListLiterals::small_block(DV));
        } else if (Kinds::get_construct(K) == CON_relation) {
            inter_name *N = RelationLiterals::default(K);
            Emit::to_value_pair(v1, v2, N);
        } else if (DV) {
            Emit::to_value_pair(v1, v2, DV);
        }
        return;
    }

    if (Kinds::eq(K, K_stored_action)) {
        inter_name *N = StoredActionLiterals::default();
        Emit::to_value_pair(v1, v2, N);
        return;
    }
    if (Kinds::eq(K, K_text)) {
        inter_name *N = TextLiterals::default_text();
        Emit::to_value_pair(v1, v2, N);
        return;
    }

    if (Kinds::eq(K, K_object)) {
        *v1 = LITERAL_IVAL; *v2 = 0;
        return;
    }

    instance *I;
    LOOP_OVER_INSTANCES(I, K) {
        inter_name *N = RTInstances::value_iname(I);
        Emit::to_value_pair(v1, v2, N);
        return;
    }

    if (Kinds::Behaviour::is_subkind_of_object(K)) {
        #ifdef IF_MODULE
        if (Task::wraps_existing_storyfile()) {
            *v1 = LITERAL_IVAL; *v2 = 0;
            return;
        }  see above
        #endif
        return;
    }

    if (Kinds::Behaviour::is_an_enumeration(K)) return;

    if (Kinds::eq(K, K_rulebook_outcome)) {
        Emit::to_value_pair(v1, v2, RTRulebooks::default_outcome_iname());
        return;
    }

    if (Kinds::eq(K, K_action_name)) {
        inter_name *wait = RTActions::double_sharp(ActionsPlugin::default_action_name());
        Emit::to_value_pair(v1, v2, wait);
        return;
    }

    text_stream *name = K->construct->default_value;

    if (Str::len(name) == 0) return;

    inter_ti val1 = 0, val2 = 0;
    if (Inter::Types::read_I6_decimal(name, &val1, &val2) == TRUE) {
        *v1 = val1; *v2 = val2; return;
    }

    inter_symbol *S = Produce::seek_symbol(Produce::main_scope(Emit::tree()), name);
    if (S) {
        Emit::symbol_to_value_pair(v1, v2, S);
        return;
    }

    if (Str::eq(name, I"true")) { *v1 = LITERAL_IVAL; *v2 = 1; return; }
    if (Str::eq(name, I"false")) { *v1 = LITERAL_IVAL; *v2 = 0; return; }

    int hl = Hierarchy::kind_default(Kinds::get_construct(K), name);
    inter_name *default_iname = Hierarchy::find(hl);
    Emit::to_value_pair(v1, v2, default_iname);
}