[REBOL] Re: "Compatibility"
From: brett:codeconscious at: 20-Feb-2003 10:29
Hi Joel,
Thank you for a very interesting post.
> our everyday/common-sense notions are exceptionally poor tools for
> reasoning about programs/languages, especially those with non-trivial
> capabilities!
> Programming (at least with non-trivial languages ;-) isn't trivial,
> regardless of our desires!
I don't disagree with those two statements, though they were not what
immediately came to my mind after reading the article (the wiki page
exhausted my reading time). Side note: replace the word "Programming" with
Communication
and your second statement is even more applicable. :^)
What caught me eye most in the article (and was not a suprise) was the last
sentence of this quote:
<quote>
In this paper, I use two running examples. The first is the old riddle, "Is
a circle a subtype of an ellipse?" and the second is, "Is a working person a
subtype of a person?" The answer I give is an agressive form of "it
depends":
Those questions cannot be answered as phrased (this should not be a surprise
to the reader). They cannot be answered when given the abstract definition
of all items. In fact, they cannot be answered even when given concrete
implementations in any mathematical or executable language (this should be a
surprise to the reader). They cannot be answered except in the context of an
interpreting environment, where the usage of the items is known.
<end-quote>
This goes to the heart of my interest in REBOL and its goal of being a
messaging language
. The statement has important implications for REBOL and
XML dialects in our increasingly inter-networked world. When passing
messages it is most likely that the "usage of the items" is *not* known
(even if they are supposed to be defined). Actually, even within a fairly
controlled non-networked corporate environment, my experience has taught me
that the interpreting environment changes over time.
I think that REBOL's design (words as symbols) embraces this issue. Not by
treating the issue as a problem, but by accepting it as a fact. Where this
leads, I'm not sure. I would have liked to have seen more practicle examples
of REBOL dialects used for messaging by now. Instead I glance at the XML
based world to see what progress/backsteps are being made.
Thanks again for a thought provoking post.
Regards,
Brett.
