World: r3wp

There is not variables, there are just values, and symbols associated 
with the values.

So one aspect you can teach is the difference between op!s action!s 
and native!s  vs  function!s.

Ok Jaime. Not sure what PLT and CTM stand for though... Core Training 
Manual?

Yes, strange concept: variables != symbols

The values are typed, but you don't need to declare its type. The 
type is recognized at parsing time by the literal representation 
of the value, ie: 1 is integer!, #"a" is a char!, "hello" is a string!, 
1x1 is pair!, 1.1.1.2 is tuple! (not a struct!), etc.

very Logo like, Dennis

Hum, Logo like Rebol... yes, maybe. I see the similarity. But why 
is Logo so much easier to learn? I will think about that.

PLT Book == http://www.htdp.org/

CTM Book == http://www.info.ucl.ac.be/~pvr/

the one on htdp doesn't seem to be about Rebol...?

Carl Sassenrath said that the heart of rebol is in denotational semantics. 
So I went and started reading 
http://www.cis.ksu.edu/~schmidt/text/densem.html


and it is true, you can see and understand the roots of rebol better 
afterwards.

DrScheme?

The part of Logo that works is turtle graphics in Draw.   Students 
get quick results.  So they experiement and learn.  See Gregg's Logo 
talk...where REBOL needs more "turtles"

It would be cool to build a sort of proto-tree.  So you can see where 
in the tree a word is related.

I created a graphic language that effectively had two commands:

Draw: at an xy point and
Circle: which had center coordinates, radius, angle and divisor.

The angle and devisor allowed you to pull an interesting trick.  


So to make a square, you simply called it with a divisor of 4.  this 
would build a string (block) with 4 pairs.  If you wanted a diamond, 
set the angle to 45.
 
You then passed the string to draw.


This may seem like a weird way to do this, but it was perfect for 
a real time rending system that was interactive.  We use this in 
a draw program like Flash.

Now another concept is that you can make those symbols designate 
 any value at any time. So 1 + 1 == 2 or a: 1 a + 1 == 2

So symbols can take place for values, in standard funcs.

BTW, The interpreter transform the infix form into a prefix form: 
1 + 1 is really + 1 1

Anton, Josh and I are planning to visit KSU very soon, what a cooincidence...to 
teach them how to teach using Predictive CognitionTM.

Forward thinking
, you mean ?

I missed the KSU....is that Kansas, or Kennesaw??

Kansas State University.

Another concepts is that a symbos (kinow in rebol as a word) can 
have found different forms.

downloaded the text on denotational semantics, Anton. Interesting.

keep on Jaime. Reading...

MY-WORD  is a symbol and get evualted to the value inmediately.

interesting talk - why this group is not web-public? :-)

Yeah, it's great. I didn't know much about densem before.

MY-WORD: (notice the colon) is the what is used to bind a word (kind 
of a C assignment)

:MY-WORD (notice the colon again) is the another way to access the 
value imagine it to be get the value, it is useful to get values 
that will cause evaulation like functions.

Difference between symbol and variable: A symbol can be of any type 
and does not get declared. Period. Is that correct?

Correct.

:word word:  Like pointers.

Are they pointers?

Rebol  is strongly typed dynamic language. While C is strongly typed 
static language (types are declared).

Note: I mentioned the Draw Circle thing, it may have seemed out of 
contect…but I was thinking about the fact that about two dozen commands 
were generated from just these two in terms of proto.

There are not pointers in Rebol they are not necessary.

So all no pointer math here.

I think Jaime is trying to speak more in the terminology you understand 
from other languages, but by "symbol" he really should say "word!".

The interpreter does the memory management for you.

Reichart, you are working on defining the paradigm of the language. 
I think that is the right direction to follow to generate a faster 
learning map of Rebol.

No pointer math, like in Java. But maybe they are pointers anyway, 
of similar.

Words usually automatically "decay" (in rebol terminology they "reduce") 
to their associated value (if they have one).

Ok, Anton, word is the word :-)

On last form is 'MY-WORD (Notice the single quote) it is a way to 
way to 'quote' a symbol this is useful when doing DATA as CODE. Another 
major concept in rebol.

If that value is a "hot" one (like a function!) then the get-word 
syntax  (:word)  will prevent the evaluation whilst still allowing 
you to get the value.

And the idea of a graph giving the family tree of the language is 
terrific.

That is in rebol the data remains data until it is interpreted. It 
is not transform into some bytecode or something else it is just 
data.

you can always probe system

Yes Jaime, what you are explaining is indeed a fundamental concept 
in Rebol. And one that has to be mastered early.

denismx regarding the books I mention even though they are not about 
rebol. They introduce a lot fo the concepts of Rebol.