Je was op zoek naar: functionality (Japans - Engels)

to emulate the functionality of add_next_index_*(), you can use this:
zend_hash_next_index_insert( ht, zval **new_element, sizeof(zval *), null)

the functionality part implements the functionality of the language (its functions, etc.).
to implement a web script interpreter, you need three parts:

"extending php" is easier said than done. php has evolved to a full-fledged tool consisting of a few megabytes of source code, and to hack a system like this quite a few things have to be learned and considered. when structuring this chapter, we finally decided on the "learn by doing" approach. this is not the most scientific and professional approach, but the method that's the most fun and gives the best end results. in the following sections, you'll learn quickly how to get the most basic extensions to work almost instantly. after that, you'll learn about zend's advanced api functionality. the alternative would have been to try to impart the functionality, design, tips, tricks, etc. as a whole, all at once, thus giving a complete look at the big picture before doing anything practical. although this is the "better" method, as no dirty hacks have to be made, it can be very frustrating as well as energy- and time-consuming, which is why we've decided on the direct approach.
when structuring this chapter, we finally decided on the "learn by doing" approach.