transversing associative arrays from C

Hi, I am working on a C extension module for PHP and am wondering about an API issue. I can see how to add to an associative array :- zval *aa; MAKE_STD_ZVAL(aa); array_init(aa); add_assoc_string(aa, "test", "test value", 1); but how do I transverse an associative array of values in a for loop simular to using "foreach" in PHP ? Hope this is not too OT for this list, but I could not find a better place to ask the question. I have looked through the API SVN sources and this seems like a possible blind spot. Many thanks in advance, Aaron