Nice. I've been using iterators for so long I've forgotten about some of these more basic ones. And the globiterator itself let .'s into it depending on the flags.
To make sure its within scope, you simply add it to this page to be accessible or to a file that is included into this one. Sounds like its not in scope though since the original code would have thrown a fatal error since it would have had a syntactical error. Functions are global so long as they are not nested and are not a part of a class or namespace. Conditional branches also dictate if functions are available, so don't put it in an if condition.