World: r3wp

If you write you return like this, it will work:

return build-markup rejoin ["<%" level "%>"]

Geomol: No, sorry I can't understand. level is defined one line before 
I use build-markup ( forget the print statement).

Now we force the value of level inside the string, before the string 
is giving to build-markup

You're right, it works well. But I still don't understand the behaviour.

In my last example, the string become something like {<%3%>}

In your example, the string is {<%level%>}. This is what build-markup 
see, and it has to figure out, what level mean. It can't figure that 
out, because level is a local of your function.

Geomol: you mean that build-markup is sort of blind on locals ?

All functions are in a situation like this. {<%level%>} is just a 
string giving to a function.

I've never seen such a behavior in whatever langage I've used, but 
I'm starting to understand it : thanks for the clarification.

Maybe you can think of it as two persons, one giving the other a 
string. The person receiving the string read "<%level%>". That person 
now have to figure out, what level mean. The person live in a context 
(the global context in this situation, because everybody can call 
build-markup). So it look up level in the global context and find 
nothing, so it gives an error.

If you instead write: rejoin ["<%" level "%>"]

then level is replaced by the value of level and a string is made, 
and this new string is sent to build-markup.

Yes, nice comparison Geomol, we see that you live in the stars :)

It's all clear now, but I shall forget about my bad habbits.

Learning REBOL is also about unlearning what you're used to. :-)

and sometimes unlearning if even more difficult than learning !

is RebGUI widely used ?

I used it for one program that was used to fix translation of Windows 
Vista in 15 or 19 different languages. It depends on your definition 
of "widely".

Rebolek: I meant "was it a good alternative to VID ?". The only thing 
I miss in every Rebol GUI I've seen is font antialiasing.

kib, if you run under Windows and wants anti-aliasing:

view layout [box black effect [draw [text "Hello World!"]]]

font-A: make face/font [size: 32]

view layout [box 200x100 black effect [draw [font font-A text "Hello 
World!"]]]

view layout [box 200x100 black effect [draw [pen red fill-pen yellow 
font font-A text "Hello W
orld!" vectorial]]]

Geomol: in this case, you're drawing them with AGG. Your text is 
not selectable.

But that gives me an idea : is there something like NodeBox in Rebol 
?

right, you figure that part out and make a nice GUI for us! :-)

No problem! give me just a min ... or a year :)

NodeBox? Something like splash?

do http://www.rebol.com/view/demos/splash.r

No, NodeBox is for poets : http://nodebox.net/code/index.php/Gallery
. Have a look at the Helsinki gallery : it's really beautiful.

Brendan Dawes' work is also interesting.

ok, looks nice!

I don't know, if anyone has done something similar in REBOL. There 
are demos flying around. I made a very simple Bezier demo once:

do http://www.fys.ku.dk/~niclasen/rebol/fysik/bezier.r

It could be a start to make something better and more beautiful.

It's like Processing ( http://processing.org/), I like this page 
made with it : http://www.wblut.com/2009/01/27/strange-symmetry-2-lite/

and REBOL got the speed, I think, if you try Cyphres demo:

do http://www.rebol.com/view/demos/cyphre.r

Fun! And you can had more control points I suppose ?

yes, shouldn't be too hard.

Whao, cypher is really quick and beautiful.

cypher --> cyphre

yup

LOL just found this:

do http://www.rebol.com/view/demos/imagination.r

move your mouse around.

Yes, wonderful job. Who did these demos ? Amiga fans ?!

hehe, they may be from a contest a few years ago. You can find them 
on the ViewTop under REBOL.com/Demos/
RZoom is also nice (by Henrik).

I'm amazed by cyphre source file : just a few lines.

I've made a C DLL on linux which has the rudiments of an image processing 
function. At the moment it just sets one pixel.

I've made C DLL on windows previously, so I will try to make it cross-platform.

Anton: interesting...do you have any screenshot ?

Boring... my test image is 2x2.

:)

What platform are you on ?

Windows (Seven)

Ugh...

I never had a problem with it since a month. It's really stable.

Ok, whatever. :-P