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[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, 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: