To read inter from a textual file.

§1. Reading textual inter. 

int no_blank_lines_stacked = 0;

void Inter::Textual::read(inter_tree *I, filename *F) {
    LOGIF(INTER_FILE_READ, "(Reading textual inter file %f)\n", F);
    default_ptree = I;
    no_blank_lines_stacked = 0;
    inter_bookmark IBM = Inter::Bookmarks::at_start_of_this_repository(I);
    inter_error_location eloc = Inter::Errors::file_location(NULL, NULL);
    TextFiles::read(F, FALSE, "can't open inter file", FALSE, Inter::Textual::read_line, 0, &IBM);
    InterSymbolsTables::resolve_forward_references(I, &eloc);
    default_ptree = NULL;
    InterTree::traverse(I, Inter::Textual::lint_visitor, NULL, NULL, -PACKAGE_IST);
    Primitives::scan_tree(I);
}

void Inter::Textual::lint_visitor(inter_tree *I, inter_tree_node *P, void *state) {
    inter_error_message *E = Inter::Defn::verify_children_inner(P);
    if (E) Inter::Errors::issue(E);
}

inter_symbol *Inter::Textual::new_symbol(inter_error_location *eloc, inter_symbols_table *T, text_stream *name, inter_error_message **E) {
    *E = NULL;
    inter_symbol *symb = InterSymbolsTables::symbol_from_name(T, name);
    if (symb) {
        if (Inter::Symbols::is_predeclared(symb)) {
            Inter::Symbols::undefine(symb);
            return symb;
        }
        *E = Inter::Errors::quoted(I"symbol already exists", name, eloc);
        return NULL;
    }
    return InterSymbolsTables::symbol_from_name_creating(T, name);
}

inter_symbol *Inter::Textual::find_symbol(inter_tree *I, inter_error_location *eloc, inter_symbols_table *T, text_stream *name, inter_ti construct, inter_error_message **E) {
    *E = NULL;
    inter_symbol *symb = InterSymbolsTables::symbol_from_name(T, name);
    if (symb == NULL) { *E = Inter::Errors::quoted(I"no such symbol", name, eloc); return NULL; }
    inter_tree_node *D = Inter::Symbols::definition(symb);
    if (Inter::Symbols::is_extern(symb)) return symb;
    if (Inter::Symbols::is_predeclared(symb)) return symb;
    if (D == NULL) { *E = Inter::Errors::quoted(I"undefined symbol", name, eloc); return NULL; }
    if ((D->W.data[ID_IFLD] != construct) && (Inter::Symbols::is_predeclared(symb) == FALSE)) {
        *E = Inter::Errors::quoted(I"symbol of wrong type", name, eloc); return NULL;
    }
    return symb;
}

inter_symbol *Inter::Textual::find_undefined_symbol(inter_bookmark *IBM, inter_error_location *eloc, inter_symbols_table *T, text_stream *name, inter_error_message **E) {
    *E = NULL;
    inter_symbol *symb = InterSymbolsTables::symbol_from_name(T, name);
    if (symb == NULL) { *E = Inter::Errors::quoted(I"no such symbol", name, eloc); return NULL; }
    if ((Inter::Symbols::is_defined(symb)) &&
        (Inter::Symbols::is_predeclared(symb) == FALSE) &&
        (Inter::Symbols::is_predeclared_local(symb) == FALSE)) {
        WRITE_TO(STDERR, "Ho! %S\n", symb->symbol_name);
        inter_tree_node *D = Inter::Symbols::definition(symb);
        Inter::Defn::write_construct_text(STDERR, D);
        *E = Inter::Errors::quoted(I"symbol already defined", name, eloc);
        return NULL;
    }
    return symb;
}

inter_symbol *Inter::Textual::find_KOI(inter_error_location *eloc, inter_symbols_table *T, text_stream *name, inter_error_message **E) {
    *E = NULL;
    inter_symbol *symb = InterSymbolsTables::symbol_from_name(T, name);
    if (symb == NULL) { *E = Inter::Errors::quoted(I"no such symbol", name, eloc); return NULL; }
    inter_tree_node *D = Inter::Symbols::definition(symb);
    if (D == NULL) { *E = Inter::Errors::quoted(I"undefined symbol", name, eloc); return NULL; }
    if ((D->W.data[ID_IFLD] != KIND_IST) &&
        (D->W.data[ID_IFLD] != INSTANCE_IST)) { *E = Inter::Errors::quoted(I"symbol of wrong type", name, eloc); return NULL; }
    return symb;
}

inter_data_type *Inter::Textual::data_type(inter_error_location *eloc, text_stream *name, inter_error_message **E) {
    inter_data_type *idt = Inter::Types::find_by_name(name);
    if (idt == NULL) *E = Inter::Errors::quoted(I"no such data type", name, eloc);
    return idt;
}

void Inter::Textual::read_line(text_stream *line, text_file_position *tfp, void *state) {
    inter_bookmark *IBM = (inter_bookmark *) state;
    inter_error_location eloc = Inter::Errors::file_location(line, tfp);
    if (Str::len(line) == 0) { no_blank_lines_stacked++; return; }
    for (int i=0; i<no_blank_lines_stacked; i++) {
        inter_error_location b_eloc = Inter::Errors::file_location(I"", tfp);
        inter_error_message *E = Inter::Defn::read_construct_text(I"", &b_eloc, IBM);
        if (E) Inter::Errors::issue(E);
    }
    no_blank_lines_stacked = 0;
    inter_error_message *E = Inter::Defn::read_construct_text(line, &eloc, IBM);
    if (E) Inter::Errors::issue(E);
}

§2. Writing textual inter. 

void Inter::Textual::writer(OUTPUT_STREAM, char *format_string, void *vI) {
    inter_tree *I = (inter_tree *) vI;
    Inter::Textual::write(OUT, I, NULL, 1);
}

typedef struct textual_write_state {
    struct text_stream *to;
    int (*filter)(inter_tree_node, int);
    int pass;
} textual_write_state;

void Inter::Textual::write(OUTPUT_STREAM, inter_tree *I, int (*filter)(inter_tree_node, int), int pass) {
    if (I == NULL) { WRITE("<no-inter>\n"); return; }
    textual_write_state tws;
    tws.to = OUT;
    tws.filter = filter;
    tws.pass = pass;
    InterTree::traverse_root_only(I, Inter::Textual::visitor, &tws, -PACKAGE_IST);
    InterTree::traverse(I, Inter::Textual::visitor, &tws, NULL, 0);
}
void Inter::Textual::visitor(inter_tree *I, inter_tree_node *P, void *state) {
    textual_write_state *tws = (textual_write_state *) state;
    if ((tws->filter) && ((*(tws->filter))(*P, tws->pass) == FALSE)) return;
    inter_error_message *E = Inter::Defn::write_construct_text(tws->to, P);
    if (E) Inter::Errors::issue(E);
}