Defining the Reference construct.

§1.

enum REFERENCE_IST

void Inter::Reference::define?Usage of Inter::Reference::define:
Definition - §3(void) {
    inter_construct *IC = Inter::Defn::create_construct(
        REFERENCE_IST,
        L"reference",
        I"reference", I"references");
    IC->min_level = 1;
    IC->max_level = 100000000;
    IC->usage_permissions = INSIDE_CODE_PACKAGE + CAN_HAVE_CHILDREN;
    METHOD_ADD(IC, CONSTRUCT_READ_MTID, Inter::Reference::read);
    METHOD_ADD(IC, CONSTRUCT_VERIFY_MTID, Inter::Reference::verify);
    METHOD_ADD(IC, CONSTRUCT_WRITE_MTID, Inter::Reference::write);
    METHOD_ADD(IC, VERIFY_INTER_CHILDREN_MTID, Inter::Reference::verify_children);
}

§2.

define BLOCK_RCE_IFLD 2
define EXTENT_RCE_IFR 3

void Inter::Reference::read?Usage of Inter::Reference::read:
§1(inter_construct *IC, inter_bookmark *IBM, inter_line_parse *ilp, inter_error_location *eloc, inter_error_message **E) {
    if (Inter::Annotations::exist(&(ilp->set))) { *E = Inter::Errors::plain(I"__annotations are not allowed", eloc); return; }

    *E = Inter::Defn::vet_level(IBM, REFERENCE_IST, ilp->indent_level, eloc);
    if (*E) return;

    inter_package *routine = Inter::Defn::get_latest_block_package();
    if (routine == NULL) { *E = Inter::Errors::plain(I"'reference' used outside function", eloc); return; }

    *E = Inter::Reference::new(IBM, ilp->indent_level, eloc);
}

inter_error_message *Inter::Reference::new(inter_bookmark *IBM, int level, inter_error_location *eloc) {
    inter_tree_node *P = Inode::fill_1(IBM, REFERENCE_IST, 0, eloc, (inter_ti) level);
    inter_error_message *E = Inter::Defn::verify_construct(Inter::Bookmarks::package(IBM), P); if (E) return E;
    Inter::Bookmarks::insert(IBM, P);
    return NULL;
}

void Inter::Reference::verify?Usage of Inter::Reference::verify:
§1(inter_construct *IC, inter_tree_node *P, inter_package *owner, inter_error_message **E) {
    if (P->W.extent != EXTENT_RCE_IFR) { *E = Inode::error(P, I"extent wrong", NULL); return; }
}

void Inter::Reference::write?Usage of Inter::Reference::write:
§1(inter_construct *IC, OUTPUT_STREAM, inter_tree_node *P, inter_error_message **E) {
    WRITE("reference");
}

void Inter::Reference::verify_children?Usage of Inter::Reference::verify_children:
§1(inter_construct *IC, inter_tree_node *P, inter_error_message **E) {
    LOOP_THROUGH_INTER_CHILDREN(C, P) {
        if ((C->W.data[0] != INV_IST) && (C->W.data[0] != REF_IST) && (C->W.data[0] != SPLAT_IST) && (C->W.data[0] != VAL_IST) && (C->W.data[0] != LABEL_IST)) {
            *E = Inode::error(C, I"only an inv, a ref, a splat, a val, or a label can be below a reference", NULL);
            return;
        }
    }
}

int Inter::Reference::node_is_ref_to(inter_tree *I, inter_tree_node *P, inter_ti seek_bip) {
    int reffed = FALSE;
    while (P->W.data[ID_IFLD] == REFERENCE_IST) {
        P = InterTree::first_child(P);
        reffed = TRUE;
    }
    if (P->W.data[ID_IFLD] == INV_IST) {
        if (P->W.data[METHOD_INV_IFLD] == INVOKED_PRIMITIVE) {
            inter_symbol *prim = Inter::Inv::invokee(P);
            inter_ti bip = Primitives::to_bip(I, prim);
            if ((bip == seek_bip) && (reffed)) return TRUE;
        }
    }
    return FALSE;
}