The Best of Creative Computing Volume 1 (published 1976)
The Parable of the Horse (A diversion intended to produce a few horse laughs)
The Parable of the Horse
Being a diversion intended to produce a few horse laughs and
perhaps some horse sense on a subject that has already fertilized too
many fields.
bv
John M. Nevison
Author note:
The author has wrangled programs of his own for many
years. He has served as a shipping clerk for Project
Conduit at the Kiewit Computation Center of Dartmouth
College. Presently he is engaged in some private ranching
on forest watershed models. Copyright 7974 by John M.Nevison.
The Parable
There was a farmer who caught a wild
horse. He put the animal to work, enlarged his
farm and called it a ranch. The idea caught on
and soon everyone was after horses to help
with their work. Horsemanship developed
apace. The wrangler was born. Horse trading
flourished. So did stealing.
After the railroads came, horses were
shipped from one range to another. Ranchers
benefitted from the increase of good animals.
And the many regions prospered as the artistry
of their breeding and the skill of their training
improved the quality of their stock.
The Animal
Bad tempered programs kick even their own
handlers.
A computer program has much in common
with a wild horse. It is temperamental; docile one
moment and vicious the next. With good training it
will return a lifetime of hard Work. It usually
performs well for only one person. And like all
living things, it eventually grows old and dies.
Programs and horses exhibit a similar variety.
There are frisky colts, hard racing two-year-olds,
even tempered mares, ornery stallions, heavy
hooved plow-horses, high stepping trotters, quick
turning quarter-horses, and broken down nags.
The Home Range
A professional who uses a computer program
without knowing how to write one is like a
rancher who has never ridden a horse: he may
succeed, but he does so under a severe
handicap.
Often a skilled academic will train a string of
programs to cover his range. How he uses a
program will vary with the geography of his
subject, the landscape of his students and the
weather of his research. Different animals are
appropriate to different tasks on a constantly
changing range.
A teacher who has learned how to ride a
program uses it with discrimination. He knows
what it does best, what its limits are, and how to
use it most efficiently. Further, like the rancher
who knows how to ride, he can manage with skill
the wranglers in his employ.
The program wrangler often adapts a
preexisting program to his own use. Even the most
docile of programs will kick and buck when a new
wrangler begins to work with it. Very few
programs are well mannered enough to work for
someone other than their master. Not surprisingly,
a wrangler learns to examine what he wants to do
and voids difficult retraining by breeding his own
program.
To get his ranch work done the professional is
constantly deciding whether to have his cowboys
breed a horse suitable to the task or import one
from another range and train it to the local tasks.
The decision depends heavily on the size of the
program.
The Size of the Beast
A nag is a nag.
All kinds of programs come in one of three
sizes: large, small, or middle. Large ones are those
that take months of a programmer's time or tens of
millions of bytes of storage on a computer. Small
ones are those less than ten lines long. The middle
size ones are those left in between.
A very large program is cumbersome enough to
move and store that a telephone connection to the
source often costs less than moving it.
A very small program is, by definition, the sort
of animal anyone can breed with no trouble on his
own range.
Programs between these extremes, written in a
language like APL, BASIC or Fortran compose the
bulk of the herd currently used in research and
instruction. Different academics will choose either
to breed or to import a middle sized program after
examining the local conditions and the cost of
shipment.
Shipping a Horse by Train
Moving a program from one computer to
another is like shipping a horse by train:
fundamentally, it does not want to go.
The cost of moving a computer program is
hard to estimate and the problems of shipping are
poorly understood.
The cowboy's preconception of how to move
one has proved wrong. His solution was to ride the
program into the boxcar, slam the door, ship it and
tell someone to ride it out at the other end. A
program actually shipped this way usually seriously
injures the first handler to get near it when it
arrives. After inflicting multiple lacerations on the
wrangler, it often dies of neglect. Sometimes it
appears in unfamiliar harness, performing
inappropriate work.
When shipping clerks from several stations
agree on how to immobilize the program in a
standard character code, with certain formats for
magnetic tape or punched cards, the cost to load,
