[REBOL] Re: 'use question
From: maarten:koopmans:surfnet:nl at: 30-Oct-2002 5:33
Why would I want to access hidden, local varaiables?
I have been wondering some time about "freezing" an interpreter in a way
that I can pass the state around.
This would be a continuation-like-thingy that can be used in distributed
computing, e.g. you have a complicated computation that is serial for
the first part, then can be parallelized.
You'd simple freeze the script in your fave' language and send the image
around. Ans that's just a sample, now if you really have imagination....
So how to proceed?
First, filter all the global word from system/words, and then filter out
the natives, the actions etc.
Also filter out anything I/O related. Later on we may abstract ports
away as "channels" where some sort of UDP transport could be used to
have the data of a "channel" follow you. Can be done, so forget it for now.
Get the values, and store them in a block.
Now we face our first problem: objects. We need to traverse objects to
filter out all I/O related variables, and they may be nested.
Tail recursion anyone? Yes, see the trhead starting with
We also me need to change make on object! types to add a 'super word for
efficiently traversing the hierarchies.
So now we can save all the state of all of the defined words. What do we
do with anonymous objects that bind a few words in the global context?
A simple way might be storing them on definition, as we are already
But what to do with words local to a value that were created using the
>> fbody: [[b] b: 10 does [b + 1]]
== [[b] b: 10 does [b + 1]]
>> f: use [b] fbody
>> get fbody/1/1
... and ...
>> set fbody/1/1 23
So that one is figured out as well.
Changing the way functions are defined some more to intercept the
current point of control flow gives us... continuation like behaviour.
That can be passed on a network? Or saved on a disk?