[REBOL] Re: native!, action!, unset!, symbol!, end!, and context!
From: g:santilli:tiscalinet:it at: 21-Jul-2004 11:54
Hi Jerry,
On Tuesday, July 20, 2004, 7:47:53 PM, you wrote:
xc> I am curious about the difference between native! and action!
ACTION!s are "methods" for datatypes.
xc> I would also like to know what symbol! and unset! are used for.
UNSET! is the value that words "with no value" have. It is also
the value returned by expression that "don't return anything".
>> type? get/any 'undefined-word
== unset!
>> type? print "hello"
hello
== unset!
>> type? do []
== unset!
SYMBOL! is an internal type.
xc> In REBOL 2.5.7.3.1, when I probed the variable
xc> "datatypes", I found end! and
xc> context!.
xc> Anyone has any info about the two datatypes.
They are internal types too. CONTEXT! is the internal value that
is used to represent contexts; you can think of it as being very
similar to a OBJECT! (or, to be more precise, you can think of
OBJECT! as being a CONTEXT! exposed to user space :).
Regards,
Gabriele.
--
Gabriele Santilli <[g--santilli--tiscalinet--it]> -- REBOL Programmer
Amiga Group Italia sez. L'Aquila --- SOON: http://www.rebol.it/
