[REBOL] Re: Global Words
From: lmecir:mbox:vol:cz at: 3-Jul-2002 9:23
Hi Ammon,
in my opinion we should distinguish two different situations. The first one
is, whether a given word exists in a given context. Example:
in system/words first to block! "xxx" ; == none
This tells us, that the word 'xxx doesn't exist in the Global context.
Another example:
o: make object! [a: 1 unset 'a]
in o 'b ; == none
This tells us, that 'b doesn't exist in the object. If we try 'a we get a
different result:
in o 'a ; == a
On the other hand, if we want to know, whether 'a has got a value, we will
find out:
value? in o 'a ; == false
, i.e. the word exists in the context, but it doesn't have a value.
Hope it is of some use,
-L
Hi,
It is a good thing that you corrected yourself, I would have let you know as
I already attempted the "unset?" version with no luck! ;-) Glad to see
that
there is a function that will let me know if a word exists in a given
context though. Thanks for the input. Oh, how valuable this list is. ;-)
Thanks!!
Ammon
A short time ago, Ladislav Mecir, sent an email stating: