[REBOL] Re: [subject: error and trial]
From: lmecir:mbox:vol:cz at: 5-Mar-2002 17:34
Hi Alan,
unfortunately, it is a different notion. See the following example:
unset 'a
value? 'a ; == false
undefined? 'a ; == false
value? first first rebol/words ; == false
undefined? first first rebol/words ; == true
set 'a 1 ; == 1
set first first rebol/words 1
** Script Error: end! is not defined in this context
** Near: set first first rebol/words 1
The difference is, that a defined word can either have a value or not, while
an undefined word cannot have a value.
Cheers
L
----- Original Message -----
From: "alan parman"
Sent: Tuesday, March 05, 2002 3:28 PM
Subject: [REBOL] Re: [subject: error and trial]
I, too am unclear on the uses of 'undefined?
Is it any different from using "not value? 'word" ? Much easier to use an
existing native value, right? ;)
