Re: Missing Something

On Mon, Nov 19, 2012 at 7:26 PM, Ron S. <[e-mail]> wrote:
> Jesus -
>
> You know exactly what I am getting at. Thank you for the reply. I will
> keep slogging away and hoping it gets easier. I am glad to have
> confirmation for what I suspected: That it is possible for a program to
> organically develop out of a linear sort of stack-oriented approach. I
> still don't see the advantage to bundling methods with objects.

Some interesting concepts about object orientation are among other
encapsulation and reusability.
If you build an object with a clean interface, the clients of the
object can forget about the internal implementation.
The advantages of this is that everything from the outside is easier,
and you are free to change the implementation without the external
code noticing (or failing).

When you have these objects with a defined behaviour and a clean
interface, they can be reused in scenarios that not even you
anticipated when you created them, and this is huge.

You should also read about the SOLID design principles and clean code,
which can be summarized with: a good design is one that is easy to
change.

Tomorrow, when you have to change some logic in your code or add some
behaviour, you would prefer that everything is in a single place, in
the *expected* place. You use a class, extend it or whatever in a
simple way and "magically" you have changed your software. All or most
of the SOLID principles involve removing duplication: when you have
the same code in two different places, the risks are huge. If you need
to change that piece of logic, you might forget one of the two (or
many) places, leading to bugs. Objects help with this thanks to the
encapsulation and reusability they provide.

> I guess
> I still think Commodore 64 style! I don't see why I shouldn't keep
> methods and objects separate is what I am saying. Methods as functions
> and objects as collections of arrays.

If the functions operate over a set of data, it's better to have them
bundled with the data as a unit, it's easier to reason about it,
change implementation, extract common behaviour with other parts of
the code, etc, etc.

> I am always doing things the hard way, knowing there is an easier way,
> but not quite knowing what the easier way is.

Well, don't despair. These things take experience. It's important to
read about this topics, and to see other's code. A book that I liked a
lot was Clean Code from Robert C. Martin.

> I'll answer a few of your questions, if you're curious...
>
>> @w = WaveFile.new(1, 44100, 16) # don't know what these numbers mean
>
> 1 - means "mono" or one channel.
> 44100 - is 44,100 frames per second (that's the rate of a Compact Disc)
> 16 - is for 16 bit.
>
> A .wav file is like a bitmap, it's uncompressed. So they're HUGE.
> Basically, the file tells a speaker where to be 44,100 times a second to
> an accuracy of 16 bits. The resting position of the speaker is 0. Fully
> out is 32768 and fully in is 32767. A speaker is basically an air pump.
>
> That's it. Sound is really simple.

Yep, sounds simple (pun intended)

>> Later, for processing, you might have several different processing
>> algorithms (I have absolutely no clue about sound processing). You can
>> create a class for each processing:
>
> That's where things are slightly difficult. It is hard to distinguish
> between what is processing, what is filtering and what is generating.
> It's all arbitrary, actually. The great thing about doing this in
> software is that it's all just moving numbers around. No wires, no
> circuit boards, no keys, nothing. It's very pure in a way. So, one is
> always torn between what makes sense in the abstract, and what is
> familiar to the end user.

The idea is that you create object that represents the concepts that
are in your domain: a filter chain composed of filters (two classes),
a generating algorithm (a factory object), transformations, etc.

> Thank you for your attention and code samples, Jesus. I think this will
> really help me organize my thinking.

Keep at it, and read about object oriented concepts, there are good
articles and books out there.

Jesus.