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From: Chris Eineke on 13 Jun 2008 15:54
When is code code, code data, data code, and data data?

I say that depends on the context. A sequence of bits can be
interpreted as a command, for example a instruction from a instruction
set for a CPU, which when "run" by the CPU has a effect on the
environment. The same sequence can also be a (part of a)
representation of something, for example a chunk descriptor in a PNG
image, which when "processed" has a effect on the environment.

Then again, you could write an interpreter for a language consisting
of that particular sequence of bits and let it mean anything you want
(start firefox, format c:, rm -rf /, etc.). Blam, you just made
context from code and data.

Fine.

So, what's context? I say it's _how_ you interpret sequences of bits.
But context itself can be put into bits. That seems like turtles all
the way down. Where does it stop? From what level of concretism can we
infer what is code and what is data?

So you break the surface of the code/data abstraction and you see
bits. Analyzed in an electricity-based context (argh!), it's a high
voltage and a low voltage with some semi-arbitrary divider between the
two. Again, a context stipulates a distinction between two sets of
entities. (I couldn't have put it any more generic, could I?)

I'm lost. While this isn't the most philosophical write-up, I am still
looking for answers. Help. :-)
From: Ole Nielsby on 13 Jun 2008 16:56
Chris Eineke <google(a)chriseineke.com> wrote:

> When is code code, code data, data code, and data data?

Code is always data.

Data is code if it is used to control a device such as a coin operated
piano, a welding machine or perhaps a computer, or if it is used to
communicate messages in a form your adversaries are supposed to
not understand.

Consider the bible.

To some people, it's a mix of historical facts and fancy tales.
No code there, just data.

To others, it's a code of conduct, telling them how to act.

And to others yet, the book is a labyrinth of trickily encoded
prophecies (beware, the stock market hints can't be trusted).

Yet it's the same bible they use.

So, it's a matter of use, not a property of the data itself.


From: David Belanger on 20 Jun 2008 17:21
On Fri, 13 Jun 2008, Chris Eineke wrote:

> So, what's context? I say it's _how_ you interpret sequences of bits.
> But context itself can be put into bits. That seems like turtles all
> the way down.

You've put your finger on it. It is turtles.
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