World: r3wp

aha, that's why it says it returns two things in help

so code is a code block and value is something that has a result 
that code block would return if I do it at the end ?

>> do/next [1 + 1 2 + 2]
== [2 [2 + 2]]

That last block is an offset reference to the original code block.

it works here too.. one strange thing is that at the last do/next 
I get right value for the end of the block and if I do/next again 
that value get's unset (I didn't know that is even possible) >>>value
** Script Error: value has no value
** Near: value<<<

>> mold/all do/next [1 + 1 2 + 2]
== "[2 #[block![1 + 1 2 + 2]4]]"

so now I just need to figure out how to detect when the last block 
is evaluated .. that is probably when the oftest block is empty...

Yup.

I mean the whole block .. (in a loop)

I will try

ha, works on all test blocks I tried :)   step-block: func [ code 
] [ until [ set/any [ value code ] do/next code empty? code ] value 
]

:)

I thought I will ask a very very stupid question and it turns out 
this is very nicely possible already

Except in R3, for now :(

would this enable us to do some sort of "green threading" without 
the need to maually yield even?

absolutely no problem , if it's "for now"

Yes, but watch out: If there is a function call, the *whole* call 
gets executed, even if it is long. Your granularity of preemption 
of your manual multithreading is going to be pretty coarse.

yes, I know.. no long running tasks as with coroutines for example 
( I am not really specialist in this, I only used it few times)

basically I don't have the full picture, it's just awesome that something 
like this can be done inside a language itself

It will be like cooperative multi-threading with no yield statement 
(that I can see), but an implied yield between top-level expressions.

yes, it looks like that .. I will try to make a simple step-blocks 
function and see what it does

if you would want to switch you could also step until you hit a certain 
word probably and then switch to other funct

With DO/next and pseudothreads you could do full fake cooperative 
multithreading.

what are pseudothreads?

you mean the R3 threads/processes?

Sorry, meant Protothreads: fake threading done with macros and special 
tricks. A C version: http://www.sics.se/~adam/pt/

The principle could be done in REBOL by preprocessing the code - 
easier than in C, though we don't have the switch trick.

C-style protothreads requires compilation to rebcode though, so we 
can use the brab opcode.

(the page doesn't load to me so I will keep trying)

Sorry, broken link. Try this: http://en.wikipedia.org/wiki/Protothreads

these things are very interesting to me but I am a little

uh.. I wanted to delete that but clicked the send button :) ..

Aren't we all "a little", sometimes :)

:)

is this how stackless works (because it mentions no stack)

If by "how stackless works" you mean Stackless Python, then no. That 
works using continuation passing style.

aha, I meant stackless pythong.. you seem to really understand this 
stuff :)

python = pythong

my "I am a little" was meant to be "unknowledgable on lower level 
things"

Protothreads often work be redoing the calling stack using special 
tricks, or with no recursion. They're good for embedded work.

interesting

They were used to implement Contiki, a multitasking embedded OS that 
runs on computers of Commodore 64-level capabilities.

I saw it mentioned on wikipedia page.. looks interesting, but it's 
website doens't work either

Contiki is used by smart sensor arrays and such. Pretty hard-core 
stuff.

I used to be an electronic studied automation so these things are 
very interesting to me... I see on google cache that last news from 
contiki site are "   Tuesday, 03 February 2009 " so it seems page 
isn't abanconed, but probably just temporatly down

(sorry for all the typos - it's late over here)

It's weird, those sites were up last November.

http://209.85.129.132/search?q=cache:0HWW7I9t-GUJ:www.sics.se/contiki/+contiki+os&hl=en&ct=clnk&cd=1

I made a simple paralel block executor .. not sure if it can be used 
for anything but it's interesting to see it work

hm... maybe I shouldn't post code here as this is R3 group

Core group