Special sentences declaring that tables amount to massed groups of assertions.

§1. Tables lie behind the special "defined by" sentence. These come in three subtly different versions:

(1) Some animals are defined by the Table of Specimens.

(2) Some men in the Zoo are defined by the Table of Zookeepers.

(3) Some kinds of animal are defined by the Table of Zoology.

The subject in (1) is the name of a kind; in (2), it's a description which incorporates a kind, but can include relative clauses and adjectives; in (3), it's something second-order — a kind of a kind. Given this variety of possibilities, we treat "defined by" sentences as if they were abbreviations for a mass of assertion sentences, one for each row of the table. We do however reject:

The okapi is defined by the Table of Short-Necked Giraffes.

where the "okapi" is an existing single animal (or indeed where it's a new name, meaning as yet unknown).

§2. So this function handles the special meaning "X is defined by Y"; it is a special meaning of "to be", recognised when Y matches — 

<defined-by-sentence-object> ::=
    defined by <np-as-object>  ==> { pass 1 }

§3. 

int DefineByTable::defined_by_SMF(int task, parse_node *V, wording *NPs) {
    wording SW = (NPs)?(NPs[0]):EMPTY_WORDING;
    wording OW = (NPs)?(NPs[1]):EMPTY_WORDING;
    switch (task) {  "The colours are defined by Table 1."
        case ACCEPT_SMFT:
            if (<defined-by-sentence-object>(OW)) {
                parse_node *O = <<rp>>;
                <np-unparsed>(SW);
                V->next = <<rp>>;
                V->next->next = O;
                return TRUE;
            }
            break;
        case PASS_1_SMFT:
        case PASS_2_SMFT:
            DefineByTable::kind_defined_by_table(V);
            break;
    }
    return FALSE;
}

§4. The timing of when to act on defined-by sentences is not completely straightforward; if it's wrong, entries making cross-references may sometimes be rejected by Inform for what seem very opaque reasons. Here's the timeline: 

void DefineByTable::kind_defined_by_table(parse_node *V) {
    wording SPW = Node::get_text(V->next);
    wording LTW = Node::get_text(V->next->next);
    LOGIF(TABLES, "Traverse %d: I now want to define <%W> by table <%W>\n",
        global_pass_state.pass, SPW, LTW);

    <defined-by-sentence-object-inner>(LTW); if (<<r>> == FALSE) return;
    table *t = Rvalues::to_table(<<rp>>);

    if (global_pass_state.pass == 1) Create whatever is in column 14.1;
    Assign properties for these values as enumerated in subsequent columns4.2;
}

§5. The object phrase is required to be a table name value: 

<defined-by-sentence-object-inner> ::=
    <s-value> |  ==> Allow if a table name5.1
    ...          ==> Issue PM_TableUndefined problem5.2

§5.1. Allow if a table name5.1 = 

    if (Rvalues::is_CONSTANT_of_kind(RP[1], K_table)) {
        ==> { TRUE, RP[1] };
    } else {
        ==> { FALSE, - };
    }

§5.2. Issue PM_TableUndefined problem5.2 = 

    StandardProblems::sentence_problem(Task::syntax_tree(), _p_(PM_TableUndefined),
    "you can only use 'defined by' in terms of a table",
    "which lists the value names in the first column.");
    ==> { FALSE, - };

§6. The subject phrase will also have to match: 

<defined-by-sentence-subject> ::=
    <article> kind/kinds of {<s-type-expression>} | ==> { TRUE, RP[2] }
    kind/kinds of {<s-type-expression>} |           ==> { TRUE, RP[1] }
    <s-type-expression> |                           ==> { FALSE, RP[1] }
    ...                                             ==> Issue PM_TableDefiningTheImpossible problem6.1

§6.1. Issue PM_TableDefiningTheImpossible problem6.1 = 

    Actually issue PM_TableDefiningTheImpossible problem6.1.1;
    ==> { NOT_APPLICABLE, - };

§6.1.1. (We're going to need this problem message twice.)

Actually issue PM_TableDefiningTheImpossible problem6.1.1 = 

    StandardProblems::sentence_problem(Task::syntax_tree(),
        _p_(PM_TableDefiningTheImpossible),
        "you can only use 'defined by' to set up values and things",
        "as created with sentences like 'The tree species are defined by Table 1.' "
        "or 'Some men are defined by the Table of Eligible Bachelors.'");

§4.1. Creation. Create whatever is in column 14.1 = 

    kind *K = NULL;
    Determine the kind of what to make4.1.1;
    Check that this is a kind where it makes sense to enumerate new values4.1.2;
    K = Kinds::weaken(K, K_object);
    if (!(Kinds::Behaviour::is_object(K))) RTTables::defines(t, K);
    t->kind_defined_in_this_table = K;
    Tables::Columns::set_kind(t->columns[0].column_identity, t, K);
    Create values for this kind as enumerated by names in the first column4.1.3;

§4.1.1. Determine the kind of what to make4.1.1 = 

    <defined-by-sentence-subject>(SPW); if (<<r>> == NOT_APPLICABLE) return;
    parse_node *what = <<rp>>;
    if (<<r>>) Rewrite in a KIND subtree4.1.1.1;
    int defining_objects = FALSE;
    if (Specifications::is_kind_like(what)) {
        K = Specifications::to_kind(what);
        if (Kinds::Behaviour::is_object(K)) defining_objects = TRUE;
    } else if (Specifications::object_exactly_described_if_any(what)) {
        Issue PM_TableDefiningObject problem4.1.1.2
        return;
    } else if (Specifications::is_description(what)) {
        Check that this is a description which in principle can be asserted4.1.1.3;
        K = Specifications::to_kind(what);
    } else {
        LOG("Error at: $T", what);
        Actually issue PM_TableDefiningTheImpossible problem6.1.1;
        return;
    }
    if (t) Tables::use_to_define(t, defining_objects, V->next);

§4.1.1.1. This is all a little clumsy, but it rewrites, say, "kinds of snake" in a little subtree under a KIND_NT node with "snake" as UNPARSED_NOUN_NT, rather than leaving "kinds of snake" as a single UNPARSED_NOUN_NT node, which would cause a new object instance to be created with that name.

Rewrite in a KIND subtree4.1.1.1 = 

    parse_node *old_node = V->next;
    parse_node *to_node = V->next->next;
    parse_node *new_node = Diagrams::new_KIND(SPW, old_node);
    wording KW = GET_RW(<defined-by-sentence-subject>, 1);
    Node::set_text(old_node, KW);
    old_node->next = NULL;
    V->next = new_node;
    V->next->next = to_node;
    what = NULL;
    if (<k-kind>(KW)) what = Descriptions::from_kind(<<rp>>, FALSE);

§4.1.1.2. Issue PM_TableDefiningObject problem4.1.1.2 = 

    StandardProblems::sentence_problem(Task::syntax_tree(),
        _p_(PM_TableDefiningObject),
        "you can only use 'defined by' to set up values and things",
        "as created with sentences like 'The tree species are defined by Table 1.' "
        "or 'Some men are defined by the Table of Eligible Bachelors.' - trying to "
        "define a single specific object, as here, is not allowed.");

§4.1.2. Check that this is a kind where it makes sense to enumerate new values4.1.2 = 

    if ((Kinds::Behaviour::is_object(K) == FALSE) &&
        (Kinds::Behaviour::has_named_constant_values(K) == FALSE)) {
        LOG("K is %u\n", K);
        Problems::quote_source(1, current_sentence);
        Problems::quote_kind(2, K);
        StandardProblems::handmade_problem(Task::syntax_tree(),
            _p_(PM_TableOfBuiltInKind));
        Problems::issue_problem_segment(
            "You wrote %1, but this would mean making each of the names in "
            "the first column %2 that's new. This is a kind which can't have "
            "entirely new values, so I can't make these definitions.");
        Problems::issue_problem_end();
        return;
    }
    if ((Kinds::Behaviour::has_named_constant_values(K)) &&
        (Kinds::Behaviour::is_uncertainly_defined(K) == FALSE)) {
        Problems::quote_source(1, current_sentence);
        Problems::quote_kind(2, K);
        StandardProblems::handmade_problem(Task::syntax_tree(),
            _p_(PM_TableOfExistingKind));
        Problems::issue_problem_segment(
            "You wrote %1, but this would mean making each of the names in "
            "the first column %2 that's new. That looks reasonable, since this is a "
            "kind which does have named values, but one of the restrictions on "
            "definitions-by-table is that all of the values of the kind have "
            "to be made by the table: you can't have some defined in ordinary "
            "sentences and others in the table.");
        Problems::issue_problem_end();
        return;
    }

§4.1.1.3. Check that this is a description which in principle can be asserted4.1.1.3 = 

    if (Propositions::contains_quantifier(
        Specifications::to_proposition(what))) {
        StandardProblems::sentence_problem(Task::syntax_tree(),
            _p_(PM_TableOfQuantifiedKind),
            "you can't use 'defined by' a table while also talking about the "
            "number of things to be defined",
            "since that could too easily lead to contradictions. (So 'Six doors are "
            "defined by the Table of Portals' is not allowed - suppose there are ten "
            "rows in the Table, making ten doors?)");
        return;
    }

§4.1.3. The following code has a curious history: it has evolved backwards from something much higher-level. When definition by tables began, it was a device to create new instances — the names in column 1 would be, say, the instances of the kind "colour". Inform did this by writing propositions to assert their existence, in an elegantly high-level way; and all was well. But people also wanted things like this:

Some people on the dais are defined by the Table of Presenters.

and the process of converting that to propositional form, while issuing a range of intelligible problem messages if anything went wrong, would end up duplicating what's already done in the assertion parser.

So Inform now handles rows in defined-by tables by handing them over to the assertions system directly. If the name N is in column 1, and the original sentence read "D are defined by...", then Inform calls the assertion-maker on the parse tree nodes for N and D exactly as if the user had written "N is D". Since this explicitly changes the meaning of N (that's the point), we then re-parse N, and check that it does now refer to an instance or kind; if it doesn't, then some assertion problem must have occurred, but if it does then the creation has worked.

Create values for this kind as enumerated by names in the first column4.1.3 = 

    parse_node *name_entry;
    int objections = 0, blank_objections = 0, row_count;
    for (name_entry = t->columns[0].entries->down, row_count = 1; name_entry;
        name_entry=name_entry->next, row_count++) {
        wording NW = Node::get_text(name_entry);
        LOGIF(TABLES, "So I want to create: <%W>\n", NW);
        if (<table-cell-blank>(NW))
            Issue a problem for trying to create a blank name4.1.3.1;
        parse_node *evaluation = NULL;
        if (<s-type-expression>(Node::get_text(name_entry))) evaluation = <<rp>>;
        Refiner::give_spec_to_noun(name_entry, evaluation);
        if (Specifications::is_kind_like(evaluation))
            Issue a problem for trying to create an existing kind as a new instance4.1.3.2;
        if ((evaluation) && (Node::is(evaluation, UNKNOWN_NT) == FALSE))
            Issue a problem for trying to create any existing meaning as a new instance4.1.3.3;
        if ((K_direction) && (<notable-map-noun-phrases>(NW)))
            Issue a problem for trying to create above or below as a new instance4.1.3.4;
        Assertions::Creator::tabular_definitions(t);
        NounPhrases::annotate_by_articles(name_entry);
        ProblemBuffer::redirect_problem_sentence(current_sentence, name_entry, V->next);
        if (Refiner::refine_coupling(name_entry, V->next, FALSE))
            Assertions::make_coupling(name_entry, V->next);
        ProblemBuffer::redirect_problem_sentence(NULL, NULL, NULL);
        Node::set_text(name_entry, NW);
        evaluation = NULL;
        if (<k-kind>(NW))
            evaluation = Specifications::from_kind(<<rp>>);
        else if (<s-type-expression>(Node::get_text(name_entry)))
            evaluation = <<rp>>;
        Refiner::give_spec_to_noun(name_entry, evaluation);
        Assertions::Creator::tabular_definitions(NULL);

        if (Node::get_subject(name_entry) == NULL)
            Issue a problem to say that the creation failed4.1.3.5;
    }
    if (objections > 0) return;

§4.1.3.1. Usually if the source text makes this mistake in one row, it makes it in lots of rows, so we issue the problem just once.

Issue a problem for trying to create a blank name4.1.3.1 = 

    if (blank_objections == 0) {
        Problems::quote_number(4, &row_count);
        StandardProblems::table_problem(_p_(PM_TableWithBlankNames),
            t, NULL, name_entry,
            "%1 is being used to create values, so that the first column needs "
            "to contain names for these new things. It's not allowed to contain "
            "blanks, but row %4 does (see %3).");
    }
    objections++; blank_objections++; continue;

§4.1.3.2. This is a special case of the next problem, but enables a clearer problem message to be issued. (It's not as unlikely a mistake as it looks, since kind names can legally be written into other columns to indicate the kinds of the contents.)

Issue a problem for trying to create an existing kind as a new instance4.1.3.2 = 

    Problems::quote_number(4, &row_count);
    StandardProblems::table_problem(_p_(PM_TableEntryGeneric),
        t, NULL, name_entry,
        "In row %4 of %1, the entry %3 is the name of a kind of value, "
        "so it can't be the name of a new object.");
    objections++; continue;

§4.1.3.3. Issue a problem for trying to create any existing meaning as a new instance4.1.3.3 = 

    LOG("Existing meaning was: $P\n", evaluation);
    Problems::quote_source(1, current_sentence);
    Problems::quote_source(2, name_entry);
    Problems::quote_kind_of(3, evaluation);
    Problems::quote_kind(4, K);
    Problems::quote_number(5, &row_count);
    StandardProblems::handmade_problem(Task::syntax_tree(), _p_(PM_TableCreatedClash));
    Problems::issue_problem_segment(
        "You wrote %1, and row %5 of the first column of that table is %2, which "
        "I ought to create as a new value of %4. But I can't do that: it already "
        "has a meaning (as %3).");
    Problems::issue_problem_end();
    objections++; continue;

§4.1.3.4. Issue a problem for trying to create above or below as a new instance4.1.3.4 = 

    Problems::quote_source(1, current_sentence);
    Problems::quote_source(2, name_entry);
    Problems::quote_kind_of(3, evaluation);
    Problems::quote_kind(4, K);
    Problems::quote_number(5, &row_count);
    StandardProblems::handmade_problem(Task::syntax_tree(), _p_(PM_TableCreatedMapClash));
    Problems::issue_problem_segment(
        "You wrote %1, and row %5 of the first column of that table is %2, which "
        "I ought to create as a new value of %4. But I can't do that: it already "
        "has a meaning (it refers to a map direction).");
    Problems::issue_problem_end();
    objections++; continue;

§4.1.3.5. Issue a problem to say that the creation failed4.1.3.5 = 

    LOG("Eval is $P\n", evaluation);
    Problems::quote_source(4, name_entry);
    Problems::quote_number(5, &row_count);
    StandardProblems::table_problem(_p_(PM_TableDefiningNothing),
        t, NULL, name_entry,
        "In row %5 of %1, the entry %4 seems not to have defined "
        "a thing there, so perhaps the first column did not consist "
        "of new names?");
    objections++; continue;

§4.2. Property assignment. Suppose column 3, say, is called "alarm call" and contains times. Clearly this is a property, and we have to give those property values to whatever has been created in their corresponding column 1s. That means those individual values need permission to have the "alarm call" property. But what about other values of the same kind which aren't mentioned in the table: do they get permission as well? We're going to say that they do.

Assign properties for these values as enumerated in subsequent columns4.2 = 

    for (int i=1; i<t->no_columns; i++) {
        table_column *tc = t->columns[i].column_identity;
        property *P = NULL;
        Ensure that a property with the same name as the column name exists4.2.1;
        if (global_pass_state.pass == 1)
            Assert::true_about(
                Propositions::Abstract::to_provide_property(P),
                KindSubjects::from_kind(t->kind_defined_in_this_table),
                prevailing_mood);
        if (t->contains_property_values_at_run_time)
            Passively allow the column to become the property values4.2.2
        else Actively assert the column entries as property values4.2.3;
    }

§4.2.1. It's probably, but not certainly, the case that the column name is new, and not yet known to be a property. If so, this is where it becomes one. By traverse 2, if not before, we will be able to give it a kind, since after table-stocking the column will have a kind for its entries.

Ensure that a property with the same name as the column name exists4.2.1 = 

    wording PW = Nouns::nominative_singular(tc->name);
    <unfortunate-table-column-property>(PW);
    P = ValueProperties::obtain(PW);
    if (ValueProperties::kind(P) == NULL) {
        kind *CK = Tables::Columns::get_kind(tc);
        if ((Kinds::get_construct(CK) == CON_rule) ||
            (Kinds::get_construct(CK) == CON_rulebook)) {
            kind *K1 = NULL, *K2 = NULL;
            Kinds::binary_construction_material(CK, &K1, &K2);
            if ((Kinds::eq(K1, K_value)) && (Kinds::eq(K1, K_value))) {
                CK = Kinds::binary_con(
                    Kinds::get_construct(CK), K_action_name, K_nil);
                Tables::Columns::set_kind(tc, t, CK);
            }
        }
        if (CK) ValueProperties::set_kind(P, CK);
    }

§7. When a table column is used to create a property of an object, its name becomes the name of a new property. To avoid confusion, though, there are some misleading names we don't want to allow for these properties. 

<unfortunate-table-column-property> ::=
    location  ==> Issue PM_TableColumnLocation problem7.1

§7.1. Issue PM_TableColumnLocation problem7.1 = 

    Problems::quote_wording(3, W);
    StandardProblems::table_problem(_p_(PM_TableColumnLocation),
        table_being_examined, NULL, table_cell_node,
        "In %1, the column name %3 cannot be used, because there would be too "
        "much ambiguity arising from its ordinary meaning referring to the "
        "physical position of something.");
    ==> { NEW_TC_PROBLEM, - };

§4.2.2. Now for something sneaky. There are two ways we can actually assign the property values: active, and passive. The passive way is the sneaky one, and it relies on the observation that if we're going to store the property values in this same table at run-time then we don't need to do anything at all: the values are already in their correct places. All we need to do is notify the property storage mechanisms that we intend this to happen.

(Take care editing this: the call works in quite an ugly way and relies on following immediately after a permission grant.)

Passively allow the column to become the property values4.2.2 = 

    if (global_pass_state.pass == 1)
        RTPropertyPermissions::set_table_storage_iname(RTTables::tcu_iname(&(t->columns[i])));

§4.2.3. Active assertions of properties are, once again, a matter of calling the assertion handler, simulating sentences like "The P of X is Y".

Actively assert the column entries as property values4.2.3 = 

    parse_node *name_entry, *data_entry;
    for (name_entry = t->columns[0].entries->down, data_entry = t->columns[i].entries->down;
        name_entry && data_entry;
        name_entry = name_entry->next,
            data_entry = data_entry->next) {
        ProblemBuffer::redirect_problem_sentence(current_sentence, name_entry, data_entry);
        Make an assertion that this name has that property4.2.3.1;
    }
    ProblemBuffer::redirect_problem_sentence(current_sentence, NULL, NULL);

§4.2.3.1. Note that a blank means "don't assert this property", it doesn't mean "assert a default value for this property". The difference is very small, but the latter might cause contradiction problem messages if there are also ordinary sentences about the property value, and the former won't.

Make an assertion that this name has that property4.2.3.1 = 

    inference_subject *subj = Node::get_subject(name_entry);
    if (global_pass_state.pass == 2) {
        if ((Wordings::nonempty(Node::get_text(data_entry))) &&
            (<table-cell-blank>(Node::get_text(data_entry)) == FALSE)) {
            parse_node *val = Node::get_evaluation(data_entry);
            if (Node::is(val, UNKNOWN_NT)) {
                if (problem_count == 0) internal_error("misevaluated cell");
            } else {
                Refiner::give_spec_to_noun(data_entry, val);
                Assertions::PropertyKnowledge::assert_property_value_from_property_subtree_infs(
                    P, subj, data_entry);
            }
        }
    }