EPtr Rewriter::rewrite_pair(EPtr pair, Creator &creator) {
if (pair) {
EPtr new_car = rewrite(EPtr(Pair::car(pair), creator.collector()), creator);
EPtr new_cdr = rewrite(EPtr(Pair::cdr(pair), creator.collector()), creator);
if (Pair::car(pair) != new_car || Pair::cdr(pair) != new_cdr) {
return creator.new_pair(new_car, new_cdr);
}
}
return pair;
}
EPtr Rewriter::rewrite_dictionary(EPtr dictionary, Creator &creator) {
Dictionary *old_dict = dictionary->as_dictionary();
bool was_modified = false;
Dictionary *parent = old_dict->parent();
if (parent) {
Dictionary *new_parent = Element::as_dictionary(rewrite_dictionary(EPtr(parent, creator.collector()), creator));
if (new_parent != parent) {
parent = new_parent;
was_modified = true;
}
}
EPtr new_dict = creator.new_dictionary(parent);
auto cur = old_dict->begin();
auto end = old_dict->end();
for (; cur != end; ++cur) {
EPtr old_value = EPtr(cur->second, creator.collector());
EPtr new_value = rewrite(old_value, creator);
if (!was_modified && old_value != new_value) {
was_modified = true;
}
new_dict->as_dictionary()->put(cur->first, new_value);
}
return was_modified ? new_dict : dictionary;
}