World: r3wp

Or forbid you using it.

there is some merit to that: what if the rebol developer quits? they 
don't exactly camp out in everybody's backyard. java developers do.

Yup, I've heard that before. It's a valid concern.

I can vouche for henriks point.  That is the single most used Anti-technology 
adoption argument.  What if  "developperX  gets hit by a train?" 
 :-(

By "valid" I mean there is some truth to it.

so, that is a factor that rebol developers should not play on

I was told "by a bus."

hehe they are sometimes scare tactics by IT managers, but are valid 
noneteless.  being 100% XML compliant "out of the box, no strings 
attached" would add DEPTH to REBOL leaps and bounds in the IT business 
IMHO.

How far are we from that?

leaps and bounds   :-)

How long is that in "Rebol Years?"

I thought RT had posted on their website that they had licensed some 
xml engine at one stage.

Haven't noticed that.

The tools exist,  senior XML developers also, heck some people even 
wrote the damned specs...  nothing is keeping RT from contracting 
out someone (or licensing technology) to add those capabilites in 
rebol natively, or as a module if its too large to keep REBOL lightweight, 
(no pro-con libs wars please).

It was some years ago.

But if they considered it once, they can do again.

blog updated: "Closure Functions"

request for R3   rebcode access to struct! types.

would allow us to implement specific mechanisms very quickly and 
gauge memory useage tradeoffs vs speed depeding on application.

It has been suggested before in the rebcode group (mostly by me) 
when rebcode was first being developed. I think there are RAMBO entries 
too.

lets all kick and scream in unison  ;-)   maybe we'll make more noise 
and rattle than all the other requests  ;-)

What's an example of how having closures will aid us ?

I think they said they needed closures for threading.

That's right, so a function could be interrupted mid-evaluation and 
restarted later.

closures haven't much to do with threading. although they are reentrant, 
while normal funcs are not (in r2; I guess it may be possible to 
make normal funcs reentrant in r3).

closures help when you want the function's context to be valid for 
an indefinite amout of time.

so, a function that maintains state ?

wasn't "indefinite extent" available in R1? just curious if it is 
similar concept?

I think you are thinking of continuations.
Closures are much more lightweight.

petr, yes, functions in r1 were actually closures. (as functions 
in lisp or scheme)

weren't they removed for 2.0 because of speed aspects?

yes, but that was not the only speed problem in r1

and, speed is the reason why you have both function!s and closure!s 
in r3

you normally use function!s that are faster

and use closure!s only when you are ready to pay the price for them 
:)

oh yeah... continuations.. oops.

don't closures also help with the copy problem?  where each time 
you run the closure, a series is indeed new?

Is there a succinct way of demonstrating a situation where a closure 
would be used (with hypothetical Rebol code)?

f: closure[ta][
 view layout [ta: area]
]

and might I ask what is the purpose of setting 'ta ?

having a local

making multiple layouts this way.

It's the layout and not 'ta that is returned though?

yes. more explicit:

f: closure[ta sl][
 view layout [ta: area sl: slider [scroll-para ta sl]]

to make some use of that local.

Is that just another way of wrapping locals in an object?
f: context [ta: none view layout [ta: area]]

ok, yes, currently only one slider will work (the last one called)

Yes, exactly.

yes, its a context within a function.