Re: typeof() creates elements in an array

[arnold]

"Andrew J. Schorr" <aschorr@telemetry-investments.com> wrote:

> > Which language in the manual, please?
>
> I was referring to the language he originally cited:
>
> "   Normally, passing a variable that has never been used to a built-in
> function causes it to become a scalar variable (unassigned).  However,
> 'isarray()' and 'typeof()' are different; they do not change their
> arguments from untyped to unassigned."

x[0] is an array element, not a variable.  :-)

It's a subtle distinction, and yes, the language above should be
clarified and expanded.

> I'm not asserting that this could be handled differently, but the
> language above does say that the type of an unused "variable" won't be
> determined by calling typeof. So the question then becomes whether x[0]
> is a "variable" and whether the mere act of passing x[0] to typeof
> constitutes "using" it. One might argue that in an ideal world, x[0]
> would have an untyped value after that code snippet; I don't know whether
> that's possible.

It may in fact be possible. I'd need to trace the path through the
code to be sure.

> In either case, with respect to your example, the length of an untyped
> or unassigned value should be 0, even if scalar vs array hasn't been
> determined, no?

Yes, but that's a side point. length() was just a convenient example.

> I suspect that this is simply impossible to do any other way, since the
> array lookup for a non-existent value looks like it has to create a new
> entry with a NODE value, and so I guess that has to have an explicit type
> at that moment. I don't think we have a notion of an untyped Node_val.

We have Node_var_new, which is pretty close.

I will look at this when I get a few minutes.

Arnold