Going out on a limb here, but I think "for" is a looping function.

Does it's invocation syntax differ significantly from the invocation syntax of other functions? Is there another function with the same invocation syntax as for? What are for's arguments? What is it's results?

These are all relevant questions when determining if it is a function or not.

Just the simple fact that loop control is determined by a boolean and requires state implies that for isn't really a function.

For what it's worth, I think Zed has a point. If you're trying to introduce a broad array of concepts to a new a programmer, going with a mapping method associated with an iterable is kind of complicated if you want to explain the whole shebang.

Compare map from Haskell, Lisp, Python etc with each. In each of those languages, you only need to introduce:

1) Named values (as variables, or not) 2) Functions 3) Lists 4) The idea that a function can take a function as an argument

You do need all the additional stuff for each that he mentions.

Similarly, in languages that make higher order functions more difficult, and have implicit state, for is an easier thing to explain.

while, until and begin .. end while/until.

And loop, of course.