Book Four
Thus spake the master programmer:
“A well-written program is its own heaven;
a poorly-written program is its own hell.”
4.1
A program should be light and agile, its subroutines connected like a
strings of pearls. The spirit and intent of the program should be
retained throughout. There should be neither too little nor too much,
neither needless loops nor useless variables, neither lack of structure
nor overwhelming rigidity.
A program should follow the ‘Law of Least Astonishment’. What is this
law? It is simply that the program should always respond to the user
in the way that astonishes him least.
A program, no matter how complex, should act as a single unit. The
program should be directed by the logic within rather than by outward
appearances.
If the program fails in these requirements, it will be in a state of
disorder and confusion. The only way to correct this is to rewrite the
program.
4.2
A novice asked the master: “I have a program that sometimes runs and
sometimes aborts. I have followed the rules of programming, yet I am
totally baffled. What is the reason for this?”
The master replied: “You are confused because you do not understand the
Tao. Only a fool expects rational behavior from his fellow humans. Why
do you expect it from a machine that humans have constructed? Computers
simulate determinism; only the Tao is perfect.
The rules of programming are transitory; only the Tao is eternal.
Therefore you must contemplate the Tao before you receive enlightenment.”
“But how will I know when I have received enlightenment?” asked the novice.
“Your program will then run correctly,” replied the master.
4.3
A master was explaining the nature of the Tao to one of his novices,
“The Tao is embodied in all software — regardless of how
insignificant,” said the master.
“Is the Tao in a hand-held calculator?” asked the novice.
“It is,” came the reply.
“Is the Tao in a video game?” continued the novice.
“It is even in a video game,” said the master.
“And is the Tao in the DOS for a personal computer?”
The master coughed and shifted his position slightly. “The lesson is
over for today,” he said.
4.4
Price Wang’s programmer was coding software. His fingers danced upon
the keyboard. The program compiled without an error message, and the
program ran like a gentle wind.
Excellent!” the Price exclaimed, “Your technique is faultless!”
“Technique?” said the programmer, turning from his terminal, “What I
follow is the Tao — beyond all technique. When I first began to
program I would see before me the whole program in one mass. After
three years I no longer saw this mass. Instead, I used subroutines.
But now I see nothing. My whole being exists in a formless void. My
senses are idle. My spirit, free to work without a plan, follows its
own instinct. In short, my program writes itself. True, sometimes
there are difficult problems. I see them coming, I slow down, I watch
silently. Then I change a single line of code and the difficulties
vanish like puffs of idle smoke. I then compile the program. I sit
still and let the joy of the work fill my being. I close my eyes for a
moment and then log off.”
Price Wang said, “Would that all of my programmers were as wise!”