Having trouble with php8 bindings

Hello

It appears that I can't use anything in PHP8.2 if the PHP file from
which I want to access xapian contains a namespace declaration,
because the PHP functions themselves cannot be found.

(xapian 1.4.22, php8.2, debian bullseye.  xapian.so is confirmed to be
loaded after manually compiling 1.4.22 packages for libxapian, and
compiling the bindings from original source, because it's not possible
to compile php8 bindings from the Debian src package presently.)

Test code on github here: https://github.com/handelaar/Xapiansearch
(Run test.php - removing the namespace refs in xapian.php and test.php
makes the problem vanish.)

Am I missing something?  Or can I use another way of calling Xapian
functions with some prefix that isn't documented? If this is as hard a
roadblock as it appears -- and I am absolutely okay with admitting I
know nothing here -- it would appear to prevent me from using the
functions in these bindings in any package or framework, which'd
rather limit its use.

Thanks for your time

jh