Hello [EMAIL PROTECTED],
On 19-Jul-00, [EMAIL PROTECTED] wrote:
> [EMAIL PROTECTED] wrote:
>
>> In REBOL you don't only have two scopes (contexts) - you have a tree of contexts,
>each one with a parent context, the top level context being what you could call
>global variables.
>
> This is probably not true; each context is independent from the
> others.
>
>> As you can see, contexts are traversed bottom-up to find the value of a word.
>
> They aren't. BIND simply binds only words that are found in the
> context --- the others are left untouched. The binding is static
> and no lookup is needed at evaluation time.
Well, I guess that's right for 'bind.
BUT if no hieraki is present, how does the following work?
REBOL [
Title "Test contexts"
]
obja: make object! [
a: "This is obja's value of 'a"
b: "This is obja's value of 'b"
objb: make object! [
b: "This is objb's value of 'b"
c: "This is objb's value of 'c"
objc: make object! [
c: "This is objc's value of 'c"
d: "This is objc's value of 'd"
test-it: func [] [
print ["words defined in this object! is:" mold first self]
print ["the value of 'a is:" mold a]
print ["the value of 'b is:" mold b]
print ["the value of 'c is:" mold c]
print ["the value of 'd is:" mold d]
]
]
]
]
obja/objb/objc/test-it
## do %test.r
words defined in this object! is: [self c d test-it]
the value of 'a is: "This is obja's value of 'a"
the value of 'b is: "This is objb's value of 'b"
the value of 'c is: "This is objc's value of 'c"
the value of 'd is: "This is objc's value of 'd"
-- end of REBOL code --
To accomplice this, I see two posibilities:
a) contexts contain a reference to their parent
b) contexts inherit from their parent
In either way, it _looks_ like a tree :-)
I might be completely wrong, please let me know :-)
>> I hope that future REBOL releases will loosen up on this in some way or another.
>
> There are some problems in allowing a word to be removed from a
> context. Adding should be feasible, I think.
What kind of problems ? (I havn't really thought this thru, I mut admit)
> Regards,
> Gabriele.
Best regards
Thomas Jensen
