cstackgliblifo

GLib stack data type?


Does GLib have a data type that can be used as a LIFO (stack) collection? It does have lists, queues, hash tables and such but I can't seem to find a stack data type.

There is a trash stack type but it was designed with a specific purpose in mind and it has also been deprecated since version 2.48.

What can be used as a stack in GLib?


Solution

  • A bit late to the party, but a more light-weight approach to a stack would be using the singly-linked list type GSList, which doesn't require an explicit container object.

    GSList *stack = NULL;
    // push:
    stack = g_slist_prepend(stack, element);
    // stack non-empty?
    if (stack) { ... }
    // peek head without popping:
    element = stack->data;
    // pop:
    stack = g_slist_delete_link(stack, stack);
    

    A wrapper function for a proper "pop" that returns the element could then look something like this:

    void *stack_pop(GSList **stackp) {
        if (!*stackp)
            return;
        void *ret = (*stackp)->data;
        *stackp = g_slist_delete_link(*stackp, *stackp);
        return ret;
    }
    // ...
    element = stack_pop(&stack); // returns NULL if stack is empty