To renumber the extensions and construct suitable functions and arrays.

§1. Our inventory inv already contains a list inv->extension_nodes of packages with the type _module which derive from extensions.

void SynopticExtensions::compile?Usage of SynopticExtensions::compile:
Make Synoptic Module Stage - §1(inter_tree *I, pipeline_step *step, tree_inventory *inv) {
    if (InterNodeList::array_len(inv->extension_nodes) > 0) Assign unique extension ID numbers1.1;
    Define SHOWEXTENSIONVERSIONS function1.2;
    Define SHOWFULLEXTENSIONVERSIONS function1.3;
    Define SHOWONEEXTENSION function1.4;
}

§1.1. Each extension module contains a numeric constant with the symbol name extension_id. We want to ensure that these ID numbers are contiguous from 1 and never duplicated, so we change the values of these constants accordingly.

Assign unique extension ID numbers1.1 =

    InterNodeList::array_sort(inv->extension_nodes, MakeSynopticModuleStage::category_order);
    for (int i=0; i<InterNodeList::array_len(inv->extension_nodes); i++) {
        inter_package *pack =
            PackageInstruction::at_this_head(inv->extension_nodes->list[i].node);
        inter_tree_node *D = Synoptic::get_definition(pack, I"extension_id");
        ConstantInstruction::set_constant(D, InterValuePairs::number((inter_ti) i+1));
    }

• This code is used in §1.

§1.2. Now we compile three functions, each of which simply prints credits out.

This is more important than it may sound because many extensions are published under a Creative Commons attribution license which requires users to give credit to the authors: Inform thus ensures that this happens automatically.

There are two forms of exemption from this —

• ● specific authorial modesty suppresses the author's name for one extension, at that extension author's discretion;
• ● general authorial modesty suppresses the author's name for any extensions by the same person who wrote the main source text.

By design, however, the author of the main source text cannot remove the name of a different author writing an extension which did not ask for modesty. That would violate the CC license.

Define SHOWEXTENSIONVERSIONS function1.2 =

    inter_name *iname = HierarchyLocations::iname(I, SHOWEXTENSIONVERSIONS_HL);
    Synoptic::begin_function(I, iname);
    for (int i=0; i<InterNodeList::array_len(inv->extension_nodes); i++) {
        inter_package *pack =
            PackageInstruction::at_this_head(inv->extension_nodes->list[i].node);
        inter_ti modesty = Metadata::read_numeric(pack, I"^modesty");
        if (modesty == 0) {
            text_stream *credit = Str::duplicate(Metadata::required_textual(pack, I"^credit"));
            WRITE_TO(credit, "\n");
            Produce::inv_primitive(I, PRINT_BIP);
            Produce::down(I);
                Produce::val_text(I, credit);
            Produce::up(I);
        }
    }
    Synoptic::end_function(I, step, iname);

• This code is used in §1.

§1.3. This fuller version does not allow the exemptions.

Define SHOWFULLEXTENSIONVERSIONS function1.3 =

    inter_name *iname = HierarchyLocations::iname(I, SHOWFULLEXTENSIONVERSIONS_HL);
    Synoptic::begin_function(I, iname);
    for (int i=0; i<InterNodeList::array_len(inv->extension_nodes); i++) {
        inter_package *pack = PackageInstruction::at_this_head(inv->extension_nodes->list[i].node);
        text_stream *credit = Str::duplicate(Metadata::required_textual(pack, I"^credit"));
        WRITE_TO(credit, "\n");
        Produce::inv_primitive(I, PRINT_BIP);
        Produce::down(I);
            Produce::val_text(I, credit);
        Produce::up(I);
    }
    Synoptic::end_function(I, step, iname);

• This code is used in §1.

§1.4. This prints the name of a single extension, identified by a value which is its extension ID. Speed of execution here is quite unimportant, so it's just a run of if (id == 1) ..., then if (id == 2) ..., and so on.

Define SHOWONEEXTENSION function1.4 =

    inter_name *iname = HierarchyLocations::iname(I, SHOWONEEXTENSION_HL);
    Synoptic::begin_function(I, iname);
    inter_symbol *id_s = Synoptic::local(I, I"id", NULL);
    for (int i=0; i<InterNodeList::array_len(inv->extension_nodes); i++) {
        inter_package *pack = PackageInstruction::at_this_head(inv->extension_nodes->list[i].node);
        text_stream *credit = Metadata::required_textual(pack, I"^credit");
        Produce::inv_primitive(I, IF_BIP);
        Produce::down(I);
            Produce::inv_primitive(I, EQ_BIP);
            Produce::down(I);
                Produce::val_symbol(I, K_value, id_s);
                Produce::val(I, K_value, InterValuePairs::number((inter_ti) (i + 1)));
            Produce::up(I);
            Produce::code(I);
            Produce::down(I);
                Produce::inv_primitive(I, PRINT_BIP);
                Produce::down(I);
                    Produce::val_text(I, credit);
                Produce::up(I);
            Produce::up(I);
        Produce::up(I);
    }
    Synoptic::end_function(I, step, iname);

• This code is used in §1.