Closures

Niko Schwarz niko.schwarz at gmx.net
Mon Feb 3 13:50:53 UTC 2003


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Am Montag, 3. Februar 2003 14:16 schrieb goran.hultgren at bluefish.se:

> I agree - both these aspects of Self are intriguing. I haven't worked in
> self so I can't say anything from personal experience.

Neither have I, unfortunately, but I found the idea very tempting.

> I bet that Self programs *have*
> classes, they are just not called that.

They have traits, and behaviour.
If I understood it all correctly, the logic is this:
When I want a car, why would I search for a concept for a car (the class) 
rather than for a car itself? 
So, what selfers do is write a proto-car, a fully blown car ready to rock, 
which you then copy if you want your "instances". objects inherit from one 
another (multiple ways, too. it complains when there would be two functions 
of that name), and it elegantly solves issues like globals: you simply 
inherit them from the Behaviour object, same as you find the other 
prototypes: they are in a tree which you can inherit, if you want it.

> The idea of building UIs "by hand" and then simply keeping the instances
> around has been tried several times and AFAIK it has been shown to have
> its own problems. 
[short description]

Yes, that sounds convincing. 
Another way would be to create a grammar that describes how the objects are 
organized. That would as well simplify the process of creating a UI-builder. 
Please don't take me too serious, I'm just thinking aloud:
I suppose it is simpler to write a ui-builder that stores its information in a 
description format, rather than producing smalltalk code that builds this ui. 
(like: ud teach every morph to print itself into an xml-tag).
With this approach, too, you would have an abstract ui description, which 
would be nice to store in the snapshot, and in your module, when you ship it.

> But anyway - the issue of focusing on "objects" instead of "source code"
> in the modularization effort has been discussed a lot on this list
> previously. IMHO I think that "simplifying" the question by saying that
> - hey, if we instead base the modules model on objects then "the rest
> will follow" simply is an oversimplification.

I guess. But pushing whole squeak more in this direction, not just modules, 
might be a useful approach. 
Maybe we two should take a better look at self and if this whole stuff really 
simplifies work, there =)

> We all know "everything" in the image are objects, much like molecules
> are in real life. Now, let's pretend that the image is the human body
> and that the different modules are the organs - the heart, brain, lungs,
> limbs etc.
>
> If I told a surgeon that "Hey, if you just figure out how to keep track
> of the dependencies between the molecules in the body - then you will
> as, a sideeffect, have solved the problem of knowing the dependencies
> between the organs!".

=) Nice analogy. 
But I understand self much simpler. It doesnt claim that it can tell you the 
dependencies better, it just wants to say that splitting the body into two 
separate parts: organ-color and organ-form, you will not simplify the process 
of understanding. better would be to watch at the organs in both their 
aspects all the time: color and structure.

regards,

nick

- -- 
	Your home electrical system is basically a bunch of wires that
bring electricity into your home and take if back out before it has a
chance to kill you.  This is called a "circuit".  The most common home
electrical problem is when the circuit is broken by a "circuit
breaker"; this causes the electricity to back up in one of the wires
until it bursts out of an outlet in the form of sparks, which can
damage your carpet.  The best way to avoid broken circuits is to change
your fuses regularly.
	Another common problem is that the lights flicker.  This
sometimes means that your electrical system is inadequate, but more
often it means that your home is possessed by demons, in which case
you'll need to get a caulking gun and some caulking.  If you're not
sure whether your house is possessed, see "The Amityville Horror", a
fine documentary film based on an actual book.  Or call in a licensed
electrician, who is trained to spot the signs of demonic possession,
such as blood coming down the stairs, enormous cats on the dinette
table, etc.
		-- Dave Barry, "The Taming of the Screw"
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