eina: Add Eina_Iterator implementation for C-array

This iterator is convenient when you already have a C-Array and you
need to pass this array to a function receiving an Eina_Iterator.

int array[] = {1, 2, 3, 4};
int* array2[] = {&array[0], &array[1], &array[2], &array[3], NULL};

Eina_Iterator* iterator = eina_carray_iterator_new((void**)array);

src/lib/eina/eina_iterator.c

@@ -174,3 +174,57 @@ eina_iterator_unlock(Eina_Iterator *iterator)
      return iterator->unlock(iterator);
    return EINA_TRUE;
 }
+
+typedef struct _Eina_Iterator_CArray Eina_Iterator_CArray;
+
+struct _Eina_Iterator_CArray
+{
+  Eina_Iterator iterator;
+
+  void** array;
+  void** current;
+};
+
+static Eina_Bool
+eina_carray_iterator_next(Eina_Iterator_CArray *it, void **data)
+{
+   if (!it->current || !*it->current)
+     return EINA_FALSE;
+
+   *data = *it->current++;
+
+   return EINA_TRUE;
+}
+
+static void**
+eina_carray_iterator_get_container(Eina_Iterator_CArray *it)
+{
+   return it->array;
+}
+
+static void
+eina_carray_iterator_free(Eina_Iterator_CArray *it)
+{
+  free(it);
+}
+
+EAPI Eina_Iterator*
+eina_carray_iterator_new(void** array)
+{
+   Eina_Iterator_CArray *it;
+
+   it = calloc(1, sizeof (Eina_Iterator_CArray));
+   if (!it) return NULL;
+
+   EINA_MAGIC_SET(&it->iterator, EINA_MAGIC_ITERATOR);
+
+   it->array = it->current = array;
+
+   it->iterator.version = EINA_ITERATOR_VERSION;
+   it->iterator.next = FUNC_ITERATOR_NEXT(eina_carray_iterator_next);
+   it->iterator.get_container = FUNC_ITERATOR_GET_CONTAINER(
+      eina_carray_iterator_get_container);
+   it->iterator.free = FUNC_ITERATOR_FREE(eina_carray_iterator_free);
+
+   return &it->iterator;
+}

src/lib/eina/eina_iterator.h

@@ -284,6 +284,21 @@ EAPI Eina_Bool eina_iterator_lock(Eina_Iterator *iterator) EINA_ARG_NONNULL(1);
  */
 EAPI Eina_Bool eina_iterator_unlock(Eina_Iterator *iterator) EINA_ARG_NONNULL(1);
 
+/**
+ * @brief Creates an Eina_Iterator that iterates through a
+ * NUL-terminated C array.
+ *
+ * @param array The NUL-terminated array
+ *
+ * You can create it like this:
+ * int array[] = {1, 2, 3, 4};
+ * int* array2[] = {&array[0], &array[1], &array[2], &array[3], NULL};
+ *
+ * Eina_Iterator* iterator = eina_carray_iterator_new((void**)array);
+ *
+ */
+EAPI Eina_Iterator* eina_carray_iterator_new(void** array) EINA_ARG_NONNULL(1) EINA_WARN_UNUSED_RESULT;
+
 /**
  * @def EINA_ITERATOR_FOREACH
  * @brief Macro to iterate over all elements easily.