1. One man’s constant is another man’s variable.
2. Functions delay binding; data structures induce binding.
Moral: Structure data late in the programming process.
3. Syntactic sugar causes cancer of the semicolon.
4. Every program is a part of some other program and rarely
fits.
5. If a program manipulates a large amount of data, it does
so in a small number of ways.
6. Symmetry is a complexity-reducing concept (co-routines
include subroutines); seek it everywhere.
7. It is easier to write an incorrect program than
understand a correct one.
8. A programming language is low level when its programs
require attention to the irrelevant.
9. It is better to have 100 functions operate on one data
structure than 10 functions on 10 data structures.
10. Get into a rut early: Do the same process the same way.
Accumulate idioms. Standardize. The only difference(!)
between Shakespeare and you was the size of his idiom list –
not the size of his vocabulary.
11. If you have a procedure with ten parameters, you
probably missed some.
12. Recursion is the root of computation since it trades
description for time.
13. If two people write exactly the same program, each
should be put into microcode and then they certainly won’t
be the same.
14. In the long run every program becomes rococo – then
rubble.
15. Everything should be built top-down, except the first
time.
16. Every program has (at least) two purposes: the one for
which it was written, and another for which it wasn’t.
17. If a listener nods his head when you’re explaining your
program, wake him up.
18. A program without a loop and a structured variable isn’t
worth writing.
19. A language that doesn’t affect the way you think about
programming, is not worth knowing.
20. Wherever there is modularity there is the potential for
misunderstanding: Hiding information implies a need to check
communication.
21. Optimization hinders evolution.
22. A good system can’t have a weak command language.
23. To understand a program you must become both the machine
and the program.
24. Perhaps if we wrote programs from childhood on, as
adults we’d be able to read them.
25. One can only display complex information in the mind.
Like seeing, movement or flow or alteration of view is more
important than the static picture, no matter how lovely.
26. There will always be things we wish to say in our
programs that in all known languages can only be said
poorly.
27. Once you understand how to write a program get someone
else to write it.
28. Around computers it is difficult to find the correct
unit of time to measure progress. Some cathedrals took a
century to complete. Can you imagine the grandeur and scope
of a program that would take as long?
29. For systems, the analogue of a face-lift is to add to
the control graph an edge that creates a cycle, not just an
additional node.
30. In programming, everything we do is a special case of
something more general — and often we know it too quickly.
31. Simplicity does not precede complexity, but follows it.
32. Programmers are not to be measured by their ingenuity
and their logic but by the completeness of their case
analysis.
33. The eleventh commandment was “Thou Shalt Compute” or
“Thou Shalt Not Compute” – I forget which.
34. The string is a stark data structure and everywhere it
is passed there is much duplication of process. It is a
perfect
