World: r3wp

Education would be better served with some clean water, food and 
a teacher.

And what sees is that anyone with any smarts leaves their country 
of birth and heads off to the USA.

Further impoverishing their bretheren.

Look at how many doctors of Indian origin now practice in the USA, 
and no longer in their own countries.

graham, i would agree with you 100%, you we're talking about teaching 
them how to get or make clear water and food, and if we train them 
as teachers (as opposed to sending teachers)

do you think that those that go to the usa don't have relatives or 
friends? and, isn't that an improvement for them at least anyway? 
keep in mind, in most of these countries, the problem is corruption, 
and sending more money makes that worse. sending laptops does not 
increase corruption at least.

sending laptos or selling laptops ?

clean water, food and a teacher

The XO connections to the net (may, will, I expect) add to the teacher 
part.  An entire generation  of youth may get that little glimpse 
that there are answers to their questions.  And then a butterfly 
flaps its wings.  :)  And one of those little ones may find out how 
to purify the local water from a HAZMAT database, and hey clean(er) 
water.

OLPC is perfect.  It's going to succeed ... perfectly.  :)

there's probably more information on the net on how to make a molotov 
cocktail than to purify water

This is inappropriate technology

Ashley, yeah, that whole micro-loan thing looked cool at first…several 
of my friends that are economists are working on a paper that analyses 
the impact of that.  It is looking very bad sadly.

Is there a way in Rebol to have the equivalent in OO programming 
of a constructor ? Can we execute a function automatically each time 
an object is created ?

You can do it by making your own MAKE function like:

omake: func [o blk /local newo] [newo: make o blk newo/c newo]


This function take 2 arguments like MAKE does. An object and a block. 
It first create a new object based on the 2 arguments. Then it call 
the function c (constructor) in the new object and finally return 
the new object. You can use it like:


>> o: make object! [a: 0 c: does [a: to-integer ask "Value? "]]	; 
This is the "class"
>> o1: omake o []
Value? 3
>> ?? o
o: make object! [
    a: 0
    c: func [][a: to-integer ask "Value? "]
]
>> ?? o1
o1: make object! [
    a: 3
    c: func [][a: to-integer ask "Value? "]
]

Thanks ! have another 2 questions about OO programming

Shoot!

1) In one of my script I have had an "OUT OF MEMORY ERROR" in a situation 
where you normally don't exect such error and don't check about it. 
Is there a way to raise an exception automatically and give control 
to the exception handler you have written ?

Can TRY be used in that situation?

Like in:

>> if error? try [4 / 0] [print "There was an error!"]
There was an error!

I'm not sure, if that catch out of memory errors.

Yes but when this error arised (during a read/lines operation) I 
asked myself if the "OUT OF MEMORY" error could accur in situations 
like function definition, object creations and so on. You don't expect 
an error expecially in the first scenario.

(first scenario: function definition)

Yes, it a bit different from "normal" errors in REBOL. I haven't 
got much experience with out of memory situations. Can you test it 
somehow, if it'll work?

I can't reproduce the out of memory error at function definition 
bur teh question remains.

Yes, good question, also regarding the new version of REBOL. I'll 
take it up with Carl and the other developers.

For the second question you should wait, my  distant syster as called 
me.

Here I am again.

Second question: if I have a word with a value, could I attach a 
method to it ? 

for example: myword: 10 and I want  a method myword.increment or 
myword/increment.

You would probably use an object for that in REBOL:

>> myword: make object! [value: 10 inc: does [value: value + 1]]

And then use paths to get the value and use inc:

>> myword/value
== 10
>> myword/inc
== 11
>> myword/value
== 11

You can also do it in a block:


>> myword: reduce ['value 10 'inc does [myword/value: myword/value 
+ 1]]
== [value 10 inc func [][myword/value: myword/value + 1]]
>> myword/value
== 10
>> myword/inc
== 11
>> myword/value
== 11
>> myword
== [value 11 inc func [][myword/value: myword/value + 1]]

With the block way, you can also get the value by:

>> myword/2
== 11

because the actual value is at the second position in the block.

On the constructor question, another way to do it is to define your 
object spec, and include initialization code in that.


>> o-spec: [time: none set-time: does [time: now/precise]  set-time]
== [time: none set-time: does [time: now/precise] set-time]
>> probe o1: context o-spec
make object! [
    time: 27-Jan-2008/11:07:00.875-7:00
    set-time: func [][time: now/precise]
]
>> probe o2: context o-spec
make object! [
    time: 27-Jan-2008/11:07:04.5-7:00
    set-time: func [][time: now/precise]
]

welcome Derek :-)

welcome Derek - at last someone newer than me ;-/

I've started a Qwiki in Qtask for the 2008 user.r rebol of the year 
awards.  The rotties.

Single category so far;  roty. 
Nominations to date;

Ashley Trüter


I'll pull the list over every month or so.   Drop a note in user.r 
if you want to nominate someone; or better yet, drop me a note for 
an invite to the user.r project on Qtask and update the Qwiki directly.

Language design discussion involving REBOL as an example:

(Personally, I think it's hard to *write* code if you don't know 
how many parameters a function takes. But maybe that's just me)
http://www.alh.net/newlisp/phpbb/viewtopic.php?p=11623#11623

And it misses the point that REBOL is more than a functional programming 
language. Besides, couldn't you just use parens everywhere if you 
want? :-)

Interesting discussion.

Is there a good example of a simple vector rendering/drawing demo 
in REBOL?

I have been thinking about a tool I want to make that allows me to 
track things around my house.  The problem with CAD programs is that 
they are designed to "create", not to record.


The concept is so different in fact that a graphical interface is 
only needed as confirmation.  Input is actually better if done "descriptively"


For example, I would rather simply measure something (like the outside 
of the house, by simply writing down every surface length, and every 
"turn").

A rectangle might be something like:

45' 10, R 10, R 10, R 10

Where the first line heads off 45 degrees (0 = North)


Then it is a matter of naming objects, and tagging them (better than 
layers, so you can display things based on tags, like "Electrical", 
"Plumbing", etc.)

Interesting idea Reichart

Reichart, i think it should be easy to do. (Especially in R3 :)

Sounds a lot like turtle graphics in Logo.

And if you have a GPS you can import and parse data from, you can 
be the turtle. :-)

Agreed, this is easy, I was just hoping to look at something already 
done, perhaps even by Richard...

The cool thing is this could be saved in XML, and be compatible with 
other systems then.


The important thing is that no CAD system I know of lets you easily 
build an object, (even like a little JBox) by telling it that it 
is x distance from the corner of some other object.  This is the 
key to logging things around a house.

I want to build a really powerful way to triangulate on a point.

uh, I don't remember the product I liked, but it working in some 
non-traditional "cad" way ...

http://www.homeplanpro.com/

well, generally I googled "cad house"

Just stopping by to say hello.  Yes, it's been a while. Sorry about 
that.  R3 has had me far out to sea - especially the Unicode changes 
of recent.

Note I have not had time to read any of the above messages (in this 
group or others).  So, if there is something important for me to 
read, let me know.

(Put a note in the Carl Only group.)

(No... created new group: Carl Links - drop a note there. Thanks!)