Comparing various methods of iterating over ds_map

ds_map_iter.gml

var map = ds_map_create();
var keys = ds_list_create();
var values = ds_list_create();
var num = 10000;
var t, k, v;
for (var i = 0; i < num; i++) {
    k = i * 2 + 1;
    v = irandom(10);
    ds_list_add(keys, k);
    ds_list_add(values, v);
    map[?k] = v;
}
// a regular situation:
t = current_time;
k = ds_map_find_first(map);
repeat (ds_map_size(map)) {
    v = map[?k];
    k = ds_map_find_next(map, k);
}
show_debug_message("normal: " + string(current_time - t)); // 721
// a separate list holds the map' keys:
t = current_time;
for (var i = 0; i < num; i++) {
    k = keys[|i];
    v = map[?k];
}
show_debug_message("keys[]: " + string(current_time - t)); // 9
// ds_map is used for key->index pairs, actual data is stored in lists:
t = current_time;
for (var i = 0; i < num; i++) {
    k = keys[|i];
    v = values[|i];
}
show_debug_message("keys[]+values[]: " + string(current_time - t)); // 6
//