Prothon Prototypes vs Python Classes

[David MacQuigg]

Playing with Prothon today, I am fascinated by the idea of eliminating
classes in Python. I'm trying to figure out what fundamental benefit
there is to having classes. Is all this complexity unecessary?

Here is an example of a Python class with all three types of methods
(instance, static, and class methods).

# Example from Ch.23, p.381-2 of Learning Python, 2nd ed.

class Multi:
numInstances = 0
def __init__(self):
Multi.numInstan ces += 1
def printNumInstanc es():
print "Number of Instances:", Multi.numInstan ces
printNumInstanc es = staticmethod(pr intNumInstances )
def cmeth(cls, x):
print cls, x
cmeth = classmethod(cme th)

a = Multi(); b = Multi(); c = Multi()

Multi.printNumI nstances()
a.printNumInsta nces()

Multi.cmeth(5)
b.cmeth(6)
Here is the translation to Prothon.

Multi = Object()
with Multi:
.numInstances = 0
def .__init__(): # instance method
Multi.numInstan ces += 1
def .printNumInstan ces(): # static method
print "Number of Instances:", Multi.numInstan ces
def .cmeth(x): # class method
print Multi, x

a = Multi(); b = Multi(); c = Multi()

Multi.printNumI nstances()
a.printNumInsta nces()

Multi.cmeth(5)
b.cmeth(6)
Note the elimination of 'self' in these methods. This is not just a
syntactic shortcut (substiting '.' for 'self') By eliminating this
explicit passing of the self object, Prothon makes all method forms
the same and eliminates a lot of complexity. It's beginning to look
like the complexity of Python classes is unecessary.

My question for the Python experts is -- What user benefit are we
missing if we eliminate classes?

-- Dave

[Jacek Generowicz]

Michael <mo*****@mlug.m issouri.edu> writes:

I follow more than 300 mailing lists on a regular basis (I get around
3 gigs of mail a day just from these lists)
Given the time this must leave you to read, understand, and
thoughtfully reply to any given article ... I'll let you draw your own
conclusions about what effect this might have on the quality of your
contributions.
and I much prefer people that top-post.
.... yup, if you are really not interested in _understanding_ what is
going on, then top-posting is for you.
Of course the only people I really hate are those that quote text
without quoting it.. so it's all on the same level and you can't tell
what they wrote from what others have written.

They should be tortured without remorse.

[Jacek Generowicz]

"John Roth" <ne********@jhr othjr.com> writes:

AFAIC, it doesn't matter whether you put your response at the
top or bottom; what matters to me is whether I can find what
you're talking about quickly. That means ruthless pruning of the
post so that old stuff gets deleted.

Look, y'all, email and usenet aren't all that dissimilar, in this
respect, from face-to-face conversation which has been
interrupted. Imagine you pick up a conversation whith someone, which
was interrupted a few minutes, hours, or days before.

Do you go up to your interlocutor, say whatever you wanted to say
next, and then recite (both sides of) the whole conversation you had
before? No.

Do you _first_ repeat (both sides of) the whole conversation you had
before, and at the very end (ten minutes later, or so) say whatever it
is that you wanted to say? No. Does your interlocutor then repeat
everything both of you have said so far once again, before adding his
new contribution? No.

Or, do you, re-establish context by saying something like "Concerning
your point about fubaring the frobnicators", and then make your point
("I would never fubar a frobnicator, without barzotting it first") ?

Then, maybe you wish to make a second point ... in which case you
would establish the relevant context again ("As for what you said
about pinging a pong"), and make your next point, relevant to the
context you just established ("When pinging a pong, you must take care
to pang it first").
I find that people who do not make the effort to quote the relevant
part(s) of messages to which they are replying, and do not make the
effort to put their replies close to (ie just after) the relevant
citations they have left in, more often than not, also fail to make
the effort to organize their own thoughts in their entire
consideration of the discussion.

Exchanges with top-posters are usually of a low quality: top-posting
makes it difficult to follow the thread ... but top-posters tend to
write codswallop more often that those who trim and organize their
replies carefully.

This is partly because the process of trimming the original post,
forces you to identfy the relevant points being made, which helps you
notice more clearly what is actually being said. Partly, it is because
if you post on usenet for more than a day and fail to notice that
top-posting sucks, then ... well, that says something about your
perspicacity.

[Michael]

Given the time this must leave you to read, understand, and
thoughtfully reply to any given article ... I'll let you draw your own
conclusions about what effect this might have on the quality of your
contribution s.

Actually I'm a major contributor to many lists. Obviously I just watch
most. Or decide a thread interests me at random points in whichI decide
to follow a list more closely for a few days. Also obvious, it's not
always the threads that have actual value that interest me.. since I've
participated in this one. I'm just amused to see this same argument
repeated pointlessly year after year.
... yup, if you are really not interested in _understanding_ what is
going on, then top-posting is for you.

I understand by having read the thread and remembered it. If I need a
context hint I can peek below but that is usually only needed with
complex interwoven threads. Which isn't the majority.. which is why I
think top-posting is good for a majority of messages but inline
bottom-posting is good other times. Use what is best for the given message.

[Ed Cogburn]

R Baumann wrote:

one follows the "standard" of the newsgroup one is participating in.

No such thing, since there is no way to enforce these "standards" , and the
bottom-posters will always bottom post, and the top-posters will always top
post no matter where they are.

Complaining whether one top posts or bottom posts is just a waste of
time, and you, me, we, all know it.

Not always, sure there are the smart asses who top-post just to annoy people,
but a lot of top-posters do that because they are newbies and don't know that
it annoys so many people. Often they just need to find out how to change
their reader program's default, or simply discover that their reader does have
such an option.

this is more irritating than whether one is "posting in the approved manner".

No it isn't, as long as someone sticks "OT" in the subject line, I don't mind
anyone talking about something else. If its identified as off topic, I can
always skip it. Top-posting on the other hand, is annoying because its
unnatural for most of us. Most of us may not say anything, and most of the
time its not "serious", but IMO, top-posting is far more irritating then OT posts.

This thread was renamed to a different subject, but that was a
half-dozen rants later in the thread than it needed to be.

Why complain about this when you're obviously still participating in this
thread two *dozen* posts after "OT" was inserted?

Get my point? Naw, too much to expect. I've wasted both your time and my
time with my own rant against your rants. :-)

Yep, everyone has their pet peeve, but isn't it kinda obvious by now that
there are a *lot* more people peeved about top-posting than there are peeved
at OT posts. :)

A lot of you guys seem far more interested in starting arguments and keeping
them running, than you are discussing the pros and cons of Python and
providing helpful answers. Rein in your egos, no one, and I include myself,
has anything helpful to contribute in this kind of "dust-up".

I've seen this complaint a thousand times too, and it never makes a
difference. You're basically asking people to stop being human, which is why
we designated "OT" as a warning for others that the conversation has drifted
far afield. However, we never did adopt "TP" so top-posters could warn
others, mainly because top-posting is not seen as inevitable, irresistible
human behavior, it is of course simply an example of laziness (or ignorance),
nothing more. While laziness is inevitable in some humans, its still not
accepted behavior. People arguing with one another is perfectly natural, and
has been going on for millenia, but for most of the world, its written
conversations are done top-to-bottom, not bottom-to-top.

[Roy Smith]

What makes you think people who top post don't also put a lot of effort
into carefully organizing their replies and trimming the original post
down to the most relevant points?

Jacek Generowicz <ja************ **@cern.ch> wrote:

top-posters tend to write codswallop more often that those who trim
and organize their replies carefully.

This is partly because the process of trimming the original post,
forces you to identfy the relevant points being made

[Markus Wankus]

Jacek Generowicz wrote:

Markus Wankus <ma************ **************@ hotmail.com> writes:

Right. So if we'd all just settle on top-posting things wouldn't be
so bad after all. It's all you bottom-posters that are screwing
things up for the rest of us. ;o)

Did you actually _understand_ what he wrote? Yes, I did notice the
smiley, but I also noticed the apparent complete failure to get the
point.

Geez..you can't even joke about this apparently. OK. Whatever. I'm
easy. I *did* get the point BTW...
Even if _everyone_ top-posts, then the reading direction is still
inconsisitent and requires the reader to jump back and-forth, to
understand what is going on.
Yes.
Please _think_ about it. It really doesn't take very much thought to
understand that top-posting sucks, but it does require some. More than
top-posters seem to be able to muster, it seems.

Alright.

--

MAN! There are some passionate individuals here. In fact, a few
minutes after my lighthearted post I received a flood of IP spoofing
attacks on my router (you know who you are). Man! Take it easy, grab a
beer (or whatever tickles your fancy) and chill. Code something - that
usually helps me. Just don't use VB or C++. ;o)

Markus.

[Glenn Andreas]

In article <sl************ ****@gate.notch arles.ca>,
Joe Mason <jo*@notcharles .ca> wrote:

In article <69************ **************@ posting.google. com>, has wrote:

Joe Mason <jo*@notcharles .ca> wrote in message
news:<sl******* *********@gate. notcharles.ca>. ..

In article <69************ **************@ posting.google. com>, has wrote:
> # Library pseudocode
>
> _fooRegistry = []
>
> obj _Foo: # prototype object
> # Foo's code goes here
>
> def Foo(): # constructor function
> newFoo = _Foo.copy()
> _fooRegistry.ap pend(newFoo)
> return newFoo
>
>
> Dirt simple with not an ounce of class metaprogramming in sight.

Is Foo() the standard syntax for making a new _Foo object? If this is a
new wrapper you just created, then it's no different than adding a
register() method - the user has to know that something different is
being done.

If Foo() is the standard syntax, and you're just overriding the
implementation here, does that get inherited? If so, this missed the
condition that only some of the descendants should get added to the
registry. If not - well, inheriting the constructor seems like the more
useful behaviour in general, so why not?
Don't think you've quite got the point of prototype-based OO yet.
There's no real 'standard syntax' for making objects; nor is there any
inheritance, classes, metaclasses, or instances. To create a new
object from scratch, execute the code that defines it. Alternatively,
duplicate an existing object.

There certainly is a standard syntax for making objects. I need to know
how to "duplicate an existing object". Is it "obj.dup()" ?
"obj.clone( )"? "duplicate obj"? Most probably, the language (or
standard library) defines one of these, and I expect most objects to be
duplicated in the same way.

It can be a bit more subtle than that in a prototype based system, since
there are two things that are different, but have nearly identical
results, but could both be considered "duplicate an object".

In general, you don't want to _duplicate_ the object, but rather use
that object as "prototype" for the new object.

First, you can make a new object that has all the same
slots/properties/attributes as the first object - let's just call that
"clone" for now (and we'll assume single inheritence, via a slot called
"__parent")
print obj.__parent None obj.a = 1
obj.foo = def (): print "a=",self.a obj.foo() a=1 obj1 = obj.clone()
print obj1.__parent None obj.a = 2 # change something in the original object
print obj1.a # unchanged in the "clone" 1 obj1.foo() a=1

and we'll make the second object that has first object as the __parent
(and we'll pretend that the syntax is "new <some expression>"
obj2 = new obj1
print obj2.__parent <obj1> obj2.foo()

a=2 # since it inherits from obj1

(obviously, the object doesn't actually retain the binded local variable
name)

If we looked at these three objects in a debugger:

obj = <Object 0x1> { __parent: None, a: 1, foo: <Method 0x2> }
obj1 = <Object 0x3> { __parent: None, a: 2, foo: <Method 0x2> }
obj2 = <Object 0x4> { __parent: <Object 0x1> }

If we hadn't changed obj1.a, both obj1 and obj2 would behave identically
to obj (they all have the same properties, same behavior), even though
internally, they are fairly different (obj1 is independant of obj, while
obj2 is completely dependant on obj). Since both "data" and "behavior"
is inherited, this is different from traditional class/instance
organization (where an instance shares its behavior (methods) with all
other instances, but has private data). This also makes the issue of
"obj2.a = 5" important, since at that point obj2 would normally get it's
own value of "a" (and otherwise would inherit the value of obj.a), and
you'd want a clean way to alter obj.a from a method in obj2
("obj2.__parent .a = 3" would work, this is where directed resends are
used in Self).

In general, you want obj2 (since it inherits everything from obj, much
like an instance "inherits" stuff from its superclass), but both are
useful.

[Joe Mason]

In article <ga************ *************** *@news.mpls.vis i.com>, Glenn Andreas wrote:

There certainly is a standard syntax for making objects. I need to know
how to "duplicate an existing object". Is it "obj.dup()" ?
"obj.clone( )"? "duplicate obj"? Most probably, the language (or
standard library) defines one of these, and I expect most objects to be
duplicated in the same way.
It can be a bit more subtle than that in a prototype based system, since
there are two things that are different, but have nearly identical
results, but could both be considered "duplicate an object".

In general, you don't want to _duplicate_ the object, but rather use
that object as "prototype" for the new object.

First, you can make a new object that has all the same
slots/properties/attributes as the first object - let's just call that
"clone" for now (and we'll assume single inheritence, via a slot called
"__parent")

<snip example>
and we'll make the second object that has first object as the __parent
(and we'll pretend that the syntax is "new <some expression>"

<snip other example>

This is certainly how Self does it. Other prototype based languages
(such as Io) do not make this distinction. In Io, you use "clone" to
make a new object whose parent is the object it was cloned from, and
that's it.

Joe

[Robin Munn]

Roy Smith <ro*@panix.co m> wrote:

Jacek Generowicz <ja************ **@cern.ch> wrote:

top-posters tend to write codswallop more often that those who trim
and organize their replies carefully.

This is partly because the process of trimming the original post,
forces you to identfy the relevant points being made

What makes you think people who top post don't also put a lot of effort
into carefully organizing their replies and trimming the original post
down to the most relevant points?

Bitter, hard-earned experience. Some people do so, as you demonstrated,
but IMB,H-EE the vast majority do not.

Another problem that occurs when some people top-post and some do not is
that the conversation thread quickly becomes unreadable unless someone
takes the time to rearrange it into a consistent form (as I did in
composing this reply).

--
Robin Munn
rm***@pobox.com

[Aahz]

In article <25************ **************@ posting.google. com>,
Magnus Lyck? <ma****@thinkwa re.se> wrote:

Michael <mo*****@mlug.m issouri.edu> wrote in message news:<40******* *******@mlug.mi ssouri.edu>...

They're planning to remove tab indention support in 3.0? I for one would
be pissed off at such a change.

I don't think you need to worry. AFAIK Python 3 is the mythological
if-I-could-turn-back-the-clock-and-undo-all-my-mistakes version
of Python, which Guido probably won't have time to work with
until his son is big enough to help him. (He'll be 3 in November.)
It will have little regard for backward compatibility, and if it
does appear sooner than expected, you can expect Python 2.x to be
maintaned in parallel for a long time.

Not quite. Python 3000 is the mythical version; Python 3.0 is expected
to appear some day. While there will be many changes that are not
backward compatible, your "little regard" is unlikely to be true: Guido
*likes* Python.
--
Aahz (aa**@pythoncra ft.com) <*> http://www.pythoncraft.com/

"usenet imitates usenet" --Darkhawk