[REBOL] Re: Embedded objects.
From: joel:neely:fedex at: 12-Mar-2003 20:42
Hi, Terry,
Another approach...
Terry Brownell wrote:
> But what if I already have an object "Dog" and simply want to
> include that in the Bob object?
>
> I don't know if Bob will ever have a dog (or an infinite amount
> of other things), which prevents me from "pre-loading" the 'pets
> block.
>
> Basically, I want Bob to now "possess" an object called dog ...
>
If you want to be able to add arbitrary possessions an unspecified
future times, without explicitly planning ahead, then you could do
something like this:
Bob: make object! [
name: "Bob"
posessions: []
]
and then later have
SomeDog: make object! [
name: "Rover"
]
and let Bob acquire that possession by saying
append Bob/possessions reduce ["dog" SomeDog]
then, to find out the name of Bob's dog
either found? mutt: select Bob/possessions "dog" [
mutt/name
][
"no dog!"
]
If we want to allow Bob to possess more than one dog, then
dognames: []
foreach [kind what] Bob/possessions [
if kind = "dog" [append dognames what/name]
]
print dognames
Of course, all of the above could be handled more tidily by
defining the appropriate methods on Bob which manage his
possessions.
-jn-
--
Polonius: ... What do you read, my lord?
Hamlet: Words, words, words.
_Hamlet_, Act II, Scene 2
