Passing by reference
Hi,
I have a quick question. How can I pass a variable to a function by reference
(as opposed to by value) in Rebol? I have tried fiddling with "to-set-word",
literal words, etc., but to no avail. I am probably missing something
obvious.
As a quick example, how could I write, say, a function that incremented the
value of a variable. Obviously this doesn't work:
inc: func [i] [i: i + 1]
j: 0
inc j
print j
>> 0
because it just increments the value passed in to inc. How do I write inc so
that it takes a reference and modifies the thing it refers to, and how do I
then call the function (inc 'j or inc j)?
I also notice that:
a: 0 ; >> 0
b: 'a ; >> a
to-set-word b ; >> a:
to-set-word b 1 ; >> 1
a ; >> 0
so what is the point of to-set-word if I can then not use it to set the thing?
Do I need an extra block and a "do" or something like that?
I've been following the argument about conceptual models of the language,
etc., and I have to admit that it would help me too. I only just found out
about the draft manual on the web site from posts on this list (I didn't
notice a link on the web site), so I shall mug up on that and see if it helps
my understanding of how Rebol handles these issues.
Thanks in advance for any help,
Richard
