C binding issue

["kat-Zygfryd" <6667@wp.pl>]

I want to write a binding for Lua 5.0
but I encountered a problem:

in lua.h we have this definition:

typedef const char * (*lua_Chunkreader) (lua_State *L, void *ud, size_t
*sz);

question:
how do I define such a callback in Ada, so that I could set
the value of *sz from within it.

Zygfryd