Eina_Accessor usage

We start by including necessary headers, declaring variables, and initializing eina:

#include <stdio.h>

#include <Eina.h>

int
main(int argc EINA_UNUSED, char **argv EINA_UNUSED)
{
   const char *strings[] = {
      "even", "odd", "even", "odd", "even", "odd", "even", "odd", "even", "odd"
   };
   const char *more_strings[] = {
      "0", "1", "2", "3", "4", "5", "6", "7", "8", "9"
   };
   Eina_Array *array;
   Eina_List *list = NULL;
   Eina_Accessor *acc;
   unsigned short int i;
   void *data;

   eina_init();

Next we populate our array and list:

   array = eina_array_new(10);

   for (i = 0; i < 10; i++)
     {
        eina_array_push(array, strings[i]);
        list = eina_list_append(list, more_strings[i]);
     }

Now that we have two containers populated we can actually start the example and create an accessor:

   acc = eina_array_accessor_new(array);

Once we have the accessor we can use it to access certain elements in the container:

   for(i = 1; i < 10; i += 2)
     {
        eina_accessor_data_get(acc, i, &data);
        printf("%s\n", (const char *)data);
     }

Note

Unlike iterators accessors allow us non-linear access, which allows us to print only the odd elements in the container.

As with every other resource we allocate we need to free the accessor(and the array):

   eina_accessor_free(acc);
   eina_array_free(array);

Now we create another accessor, this time for the list:

   acc = eina_list_accessor_new(list);

And now the interesting part, we use the same code we used above, to print parts of the array, to print parts of the list:

   for(i = 1; i < 10; i += 2)
     {
        eina_accessor_data_get(acc, i, &data);
        printf("%s\n", (const char *)data);
     }

And to free the list we use a gimmick, instead of freeing list, we ask the accessor for its container and we free that:

   eina_list_free(eina_accessor_container_get(acc));

Finally we shut eina down and leave:

   eina_accessor_free(acc);

   eina_shutdown();

   return 0;
}

The full source code can be found in the examples folder in the eina_accessor_01.c file.