terminological obscurity

[Arthur]

On Thu, 27 May 2004 19:30:40 +0200, "Martin v. Löwis"
<martin at v.loewis.de> wrote:
>
>It is very clear to my why he did not say what Donn said - because
>he thought that the notion of homogenous and heterogenous is obvious
>to anybody.

FIRST
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The name of our thread is "terminological obscurity". And I expect
that the orignal poster had as good a grasp as you (or I) as to the
meaning of homogenous and heterogenous. 

And it is certainly easy for Martin or Donn to assume that we are
talking technically over the head of someone like myself.  I'll go
fuirther and allow us to assume that is part of what is going on.

Another part of what is going on has nothing to do with that at all.
It is about lnaguage and it is about logic and it is about the
dynamics of groups.

My involvement in this discussion began in reaction to a statment made
to the typical question about why tuples *and* lists are in the
language:

Assume """ surrounds *exact* quotes from the newsgropup.

"""
It's a common question. A list is a data structure that is
intended to be used with homogenous members; that is,
with members of the same type.
"""

and in defense of a challange to this statement based on the
flexibility of Python of handling data of different types in a list,
came this response:

"""
This is perfectly true, but that's the intention. Guido says
so himself. Lots of people either don't believe him, or
don't understand him.
"""

So that, in effect, was the first time I was told that the problem is
I don't understand what Guido meant, i.e. I didn't understand that
lists were designed to be used " with homogenous members, that is
weith members of the same type".

Thankfully Donn interceded at that point to bring the dicussion more
onto a sensible track. 

And as a result:

We all agree, (do we not) at this point - even the poster of these
remarks -   if that is what Guido in fact meant, I was doing good not
to understand him, (or believe him if I did.)

SECOND 
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When Donn thought the terminology "homogenous data" and "hetereogenous
data" in the context of the discussionss were coming from me, or other
"unofficial" sources, he implied strongly that the use of this
terminology was part of what was creating some misunderstanding of the
concepts involved.

When I told him the terminology was not mine, but Guido's my lack of
understanding (that being the constant) now became that I didn't
understand what Guido meant when he used the terminology which was a
moment ago unacceptable.  That is the second time I was told the
problem  was *my* capacity to understand what Guido meant.
>
>He then *also* said something about how static typing might be
>introduced into Python - but that was about possible static typing,
>not about the terms "homogenous" and "heterogenous". Even with
>static typing, it might be possible to declare a list that is
>statically typed, contains homogenous data, and yet contains
>objects as different as None and a module. The type of this
>list might be "list of (NoneType union ModuleType)", better
>declared as "list of optional ModuleType".

THIRD 
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Donn. who I think we agree, brought some light to this discussion did
state clearly, I think, that the use of the "homogenous data" (in
describing for example  None and a module) is bad and misleading
terminolgy.  Perhaps, because it supports too well a supposition that
we are only talking in tautologies. What can be said be homogenous
about such data, outside of the membership in a list?  Donn suggests
the list is homogenous, even if the data is not, in any meaningful
sense.  I think I understand that a bit.

Yet you insist, with a fresh start on all this, on using the
terminology "homogenous data".

I don't understand Martin any better thatn I understand Guido.

In fact I am totally lost.

Art