Defining the cast construct.

§1.

enum CAST_IST

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

§2.

define BLOCK_CAST_IFLD 2
define TO_KIND_CAST_IFLD 3
define FROM_KIND_CAST_IFLD 4
define EXTENT_CAST_IFR 5

void Inter::Cast::read?Usage of Inter::Cast::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, CAST_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"'val' used outside function", eloc); return; }

    inter_symbol *from_kind = Inter::Textual::find_symbol(Inter::Bookmarks::tree(IBM), eloc, Inter::Bookmarks::scope(IBM), ilp->mr.exp[1], KIND_IST, E);
    if (*E) return;
    inter_symbol *to_kind = Inter::Textual::find_symbol(Inter::Bookmarks::tree(IBM), eloc, Inter::Bookmarks::scope(IBM), ilp->mr.exp[0], KIND_IST, E);
    if (*E) return;

    *E = Inter::Cast::new(IBM, from_kind, to_kind, (inter_t) ilp->indent_level, eloc);
}

inter_error_message *Inter::Cast::new(inter_bookmark *IBM, inter_symbol *from_kind, inter_symbol *to_kind, inter_t level, inter_error_location *eloc) {
    inter_tree_node *P = Inter::Node::fill_3(IBM, CAST_IST, 0, Inter::SymbolsTables::id_from_IRS_and_symbol(IBM, to_kind), Inter::SymbolsTables::id_from_IRS_and_symbol(IBM, from_kind), eloc, (inter_t) 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::Cast::verify?Usage of Inter::Cast::verify:
§1(inter_construct *IC, inter_tree_node *P, inter_package *owner, inter_error_message **E) {
    if (P->W.extent != EXTENT_CAST_IFR) { *E = Inter::Node::error(P, I"extent wrong", NULL); return; }
    *E = Inter::Verify::symbol(owner, P, P->W.data[TO_KIND_CAST_IFLD], KIND_IST); if (*E) return;
    *E = Inter::Verify::symbol(owner, P, P->W.data[FROM_KIND_CAST_IFLD], KIND_IST); if (*E) return;
}

void Inter::Cast::write?Usage of Inter::Cast::write:
§1(inter_construct *IC, OUTPUT_STREAM, inter_tree_node *P, inter_error_message **E) {
    inter_symbols_table *locals = Inter::Packages::scope_of(P);
    if (locals == NULL) { *E = Inter::Node::error(P, I"function has no symbols table", NULL); return; }
    inter_symbol *from_kind = Inter::SymbolsTables::symbol_from_frame_data(P, FROM_KIND_CAST_IFLD);
    inter_symbol *to_kind = Inter::SymbolsTables::symbol_from_frame_data(P, TO_KIND_CAST_IFLD);
    if ((from_kind) && (to_kind)) {
        WRITE("cast %S <- %S", to_kind->symbol_name, from_kind->symbol_name);
    } else { *E = Inter::Node::error(P, I"cannot write cast", NULL); return; }
}

void Inter::Cast::verify_children?Usage of Inter::Cast::verify_children:
§1(inter_construct *IC, inter_tree_node *P, inter_error_message **E) {
    int arity_as_invoked = 0;
    LOOP_THROUGH_INTER_CHILDREN(C, P) {
        arity_as_invoked++;
        if ((C->W.data[0] != INV_IST) && (C->W.data[0] != VAL_IST) && (C->W.data[0] != EVALUATION_IST) && (C->W.data[0] != CAST_IST)) {
            *E = Inter::Node::error(P, I"only inv, cast, concatenate and val can be under a cast", NULL);
            return;
        }
    }
    if (arity_as_invoked != 1) {
        *E = Inter::Node::error(P, I"a cast should have exactly one child", NULL);
        return;
    }
}