Defining the comment construct.

§1. Definition. Comments are present in Inter bytecode as actual instructions, enabling them to be preserved in binary Inter files. But they have no effect on the meaning or execution of a program.

void CommentInstruction::define_construct(void) {
    inter_construct *IC = InterInstruction::create_construct(COMMENT_IST, I"comment");
    InterInstruction::specify_syntax(IC, I"#ANY");
    InterInstruction::data_extent_always(IC, 1);
    METHOD_ADD(IC, CONSTRUCT_TRANSPOSE_MTID, CommentInstruction::transpose);
    METHOD_ADD(IC, CONSTRUCT_VERIFY_MTID, CommentInstruction::verify);
    METHOD_ADD(IC, CONSTRUCT_READ_MTID, CommentInstruction::read);
    METHOD_ADD(IC, CONSTRUCT_WRITE_MTID, CommentInstruction::write);
    InterInstruction::allow_in_depth_range(IC, 0, INFINITELY_DEEP);
    InterInstruction::permit(IC, OUTSIDE_OF_PACKAGES_ICUP);
    InterInstruction::permit(IC, INSIDE_PLAIN_PACKAGE_ICUP);
    InterInstruction::permit(IC, INSIDE_CODE_PACKAGE_ICUP);

§2. Instructions. In bytecode, the frame of an comment instruction is laid out with the compulsory words — see Inter Nodes — followed by:

inter_error_message *CommentInstruction::new(inter_bookmark *IBM, text_stream *commentary,
    inter_error_location *eloc, inter_ti level) {
    inter_tree_node *P = Inode::new_with_1_data_field(IBM, COMMENT_IST,
        /* TEXT_COMMENT_IFLD: */ InterWarehouse::create_text_at(IBM, commentary),
        eloc, level);
    inter_error_message *E = VerifyingInter::instruction(InterBookmark::package(IBM), P);
    if (E) return E;
    NodePlacement::move_to_moving_bookmark(P, IBM);
    return NULL;

void CommentInstruction::transpose(inter_construct *IC, inter_tree_node *P,
    inter_ti *grid, inter_ti grid_extent, inter_error_message **E) {
    P->W.instruction[TEXT_COMMENT_IFLD] = grid[P->W.instruction[TEXT_COMMENT_IFLD]];

§3. Verification consists only of sanity checks.

void CommentInstruction::verify(inter_construct *IC, inter_tree_node *P,
    inter_package *owner, inter_error_message **E) {
    *E = VerifyingInter::text_field(owner, P, TEXT_COMMENT_IFLD);
    if (*E) return;

§4. Creating from textual Inter syntax.

void CommentInstruction::read(inter_construct *IC, inter_bookmark *IBM, inter_line_parse *ilp,
    inter_error_location *eloc, inter_error_message **E) {
    text_stream *commentary = ilp->mr.exp[0];
    *E = CommentInstruction::new(IBM, commentary, eloc, (inter_ti) ilp->indent_level);

§5. Writing to textual Inter syntax. The empty comment is printed back as a blank line, rather than a lone #.

void CommentInstruction::write(inter_construct *IC, OUTPUT_STREAM, inter_tree_node *P) {
    text_stream *S = Inode::ID_to_text(P, P->W.instruction[TEXT_COMMENT_IFLD]);
    if (Str::len(S) > 0) WRITE("#%S", S);