From: Eleanor McHugh <eleanor@...>
Date: 2011-06-19T22:30:28+09:00
Subject: Re: Object-Oriented thinking

On 20 May 2011, at 18:58, Michael Sokol wrote:
> Hello everyone,
> 
> What I find fascinating when hacking in Ruby, is that we use one of the
> purest implementation of OOP, and at time we find ourselves tweaking C
> extensions. Thus, the boundary between the two ways of thinking (procedural
> vs OOP) seem very thin, yet it's still fundamentally different.
> 
> My question is, what kind of mental model do you use when you program in
> Ruby? How do you think about objects? Do you see them as elements carrying
> with them their own methods, bundled with their data?

Mostly I tend to think about programming as a sort of a collaborative writing exercise between myself and the computer as we explore a particular problem space. Along the way we'll spot some interesting landmarks, chat with the natives about their lifestyle and customs, get stuck in some weird backwater or three along the way and when we get back have a really great yarn to tell.

Out of that experience we (I and Friend Computer) seem to produce this artefact called a software program with objects and classes and meta-programming adornments. 

And at times we write tests. Which is a polite way of saying we perform unethical vivisection on various of the natives we meet, take snapshots for the further edification of science, and then run away from the scene of the crime very very quickly.

> How about the flow of the program: Whenever there's a method call, do you
> picture the method to be inside the receiver - just like it would be in a
> real-life object -, or since you know that in the underlying implementation
> the method is stored in the class, you just think about a procedure call
> with a self variable being the receiver?

It's all just messages, all the way down. Often in a Schroedinger's Cat/Shakespearean tragi-comic sense.

> Do you think using the OOP abstraction without knowing the internals can be
> harmful? My case for that (even if I tend not to believe so) would be that
> someone might be tempted to think that during an object instanciation, all
> the instance variables AND methods gets duplicated for this particular
> instance, which isn't the case - yet, that's what the abstraction pushes us
> to believe.

Anything with quantum mechanics can catch us out if we fall for the fallacy of determinism. Message passing languages such as Ruby are an example of this and an object is only ever what it claims to be when asked.

Just because a Ruby object is a Dog, doesn't mean it can necessarily bark ;)


Ellie

Eleanor McHugh
Games With Brains
http://feyeleanor.tel
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raise ArgumentError unless @reality.responds_to? :reason