Defining the Code construct.

§1.

enum CODE_IST
void Inter::Code::define(void) {
    inter_construct *IC = Inter::Defn::create_construct(
        CODE_IST,
        L"code",
        I"code", I"codes");
    IC->min_level = 0;
    IC->max_level = 100000000;
    IC->usage_permissions = INSIDE_CODE_PACKAGE + CAN_HAVE_CHILDREN;
    METHOD_ADD(IC, CONSTRUCT_READ_MTID, Inter::Code::read);
    METHOD_ADD(IC, CONSTRUCT_VERIFY_MTID, Inter::Code::verify);
    METHOD_ADD(IC, CONSTRUCT_WRITE_MTID, Inter::Code::write);
    METHOD_ADD(IC, VERIFY_INTER_CHILDREN_MTID, Inter::Code::verify_children);
}

§2.

define BLOCK_CODE_IFLD 2
define EXTENT_CODE_IFR 3
void Inter::Code::read(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, CODE_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"'code' used outside function", eloc); return; }

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

inter_error_message *Inter::Code::new(inter_bookmark *IBM, int level, inter_error_location *eloc) {
    inter_tree_node *P = Inode::fill_1(IBM, CODE_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::Code::verify(inter_construct *IC, inter_tree_node *P, inter_package *owner, inter_error_message **E) {
    if (P->W.extent != EXTENT_CODE_IFR) *E = Inode::error(P, I"extent wrong", NULL);
}

void Inter::Code::write(inter_construct *IC, OUTPUT_STREAM, inter_tree_node *P, inter_error_message **E) {
    WRITE("code");
}

void Inter::Code::verify_children(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] != SPLAT_IST) && (C->W.data[0] != EVALUATION_IST) && (C->W.data[0] != LABEL_IST) && (C->W.data[0] != VAL_IST) && (C->W.data[0] != COMMENT_IST) && (C->W.data[0] != NOP_IST)) {
            *E = Inode::error(C, I"only an inv, a val, a splat, a concatenate or a label can be below a code", NULL);
            return;
        }
    }
}