From: bsmart@bsmart.TTI.COM (Bob Smart)
Subject: Re: Symbolic Interpretation (Re: Young earth creationist logic NOT!)
Reply-To: bsmart@bsmart.TTI.COM (Bob Smart)
Organization: Citicorp+TTI
Date: Thu, 3 Sep 1992 04:28:51 GMT

In article <1992Aug27.163835.12301@acuson.com>, lawson@acuson.com (Drew
Lawson) writes:
> >> I haven't
> >> kept up on recent architecture developments, but I didn't know of any
> >> machines which make use of data structures.

There aren't any computers which DON'T make use of data structures. 
What do you think a status register is?  How do you think a "return"
instruction works, other than by direct hardware manipulation of either
a return stack or some other context-restoration data structure?  Let
alone a virtual address descriptor table!  (You DO know how hardware
resolution of virtual memory addressing works, don't you?)

> By the time a program gets to the machine instruction level, there is
> no remnant of the data structures.  The same memory pattern can be
> accomplished by a tedious organization of memory blocks by an assembly
> language programmer.

That organization is "structure."

Enforcement of good coding habits by a particular coding language is not
"structure."  Absence of GOTOs is not "structure."  Presence of struct{}
or while{} is not "structure."

> The machine execution is not affected by the data
> structures.  The compiler operation is.

If machine execution is not affected by data structures, the machine is
behaving randomly.  Whether you can deduce what the structure is simply
by looking at the listing, a memory dump, or whatever, is a separate
matter.  (Are you old enough to have seen and debugged from a raw memory
dump?  Not that it matters, but I'm curious.)  The structures that were
defined in the source language, however, are still present.  When I/O
happens, data gets poured into the buffer, and not just any old where. 
Records and tables get manipulated as units, the bounds of block moves
and so forth correspond precisely to the bounds of the data structures,
and it's not coincidental.  Sure, you can write self-modifying code (on
some machines, anyway) that can change the definitions and layouts of
these structures on the fly...but that's merely a matter of replacing
one bunch of structures with another.  It's still structured, even if
it's hard to understand and debug.

> BTW, software was around for a while without the common usage of data
> structures.  So it hardly "fails to exist" in their absence.

There is NO SUCH THING as (functioning) software that doesn't use data
structures.  The structures in use might not be the neat, elegant ones
you see described in textbooks...but all programs have structure, both
in their executable parts and in their data.  To say that they are
"unstructured" is to say that they are RANDOM, and repellent as old code
can be, it isn't random.

It may be difficult for a person reading the listing (or worse yet, a
dump) to discern the structure, and the structure that is present may
not be what the original coder intended, but the fact that structure is
difficult to see does not equate to there being no structure TO see.

> Perhaps you don't know what a data structure is.  It is an
> abstraction.  A way of labeling memory with a conceptual purpose.  They
> are sometimes used without any memory allocation.

Depends on what you mean by "used."  Executing programs that access
memory without it being allocated, generally don't work real well.  In
what sense do you mean "used," if no memory access is involved?

> I also doubt that all of science would fall apart if belief in
> evolutionary origin fell by the wayside.

That's because you don't really understand either science in general, or
evolutionary biology in particular.  All the scientific disciplines are
interdependent, and when the ideas that prop up one science are
discredited, then the other sciences which depend on the same ideas are
also in deep bandini.  If you can produce a Creation-based theory that
is A) subject to hypothesis testing, B) accounts for all the available
observations, C) distinct from evolutionary theory, and D) does not
knock the stuffing out of any other disciplines, then please present it.

Note that I'm not (quite) saying that such a theory is fundamentally
impossible.  I'm just saying that I'm not nearly clever enough to
construct one...but I invite you to try your hand at it.

> What about pulsars as clear evidence of extra-stellar intelligence?

Is that what you think they are?

---------

A fanatic is someone who does what he knows that God would do if God knew the
facts of the case.

Some mailers apparently munge my address; you might have to use
bsmart@bsmart.tti.com -- or if that fails, fall back to
72027.3210@compuserve.com.  Ain't UNIX grand?
Xref: sparky sci.skeptic:14990 alt.culture.usenet:706 talk.origins:10078