The World's Hardest
Sudoku describes an IDDFS algorithm for solving
sudokus.
It is suitable for humans with paper, pencil and a copy
machine or a computer program.
The depth does not exceed 3 hypotheses for any given
sudoku.
Structural
Single State Mutinex Logic (PDF) -- Satoku Matrix in a
nut-shell. Describes an inverted adjacency matrix as a formalized state relation matrix.
FUQ-T-FAQ: Frequently Unanswered Questions To Frequently Answered
Questions
The "deprecated" warning dilemma
"This POS is deprecated. Do not use in new
code."
What if I am writing new code to
be run both on an old system and a new system?
Now, do I have to write it twice, if I do not appreciate the
stupid warnings?
Of course not, just define the new stuff in terms of the
old stuff: (unless (fboundp 'new-stuff) (defun new-stuff() (in terms of
old-stuff)))
This would also be the Python from __future__ import
new-stuff principle, if only import from __future__
did work all the way back to version 0.0.
The "cut-and-paste" conundrum (also: the library misconception)
"`Cut-and-paste' is the Devil's highway to hell."
Oh! But it feels so good!?
Well -- as with other things -- if you are doing it for
procreation, you are doing Yggod's work.
The rules for code procreation by `cut-and-paste' are simple:
If the copy is given up for adoption (i.e., nobody cares
what becomes of it):
Copy as much as possible, since everything copied
contains no additional typos.
Modify the copy to your heart's content.
If the clones may have to be refurbished at a later time:
Keep the original for reference and modification.
Prominently mark the beginning of the copied section and
never ever modify it after pasting (anchor for diff(1)).
Generally avoid modification after pasting. Instead,
modify the original and regenerate the clone(s) at your
earliest convenience. Or when hell freezes over. Whichever
comes first.
This results in the concept of a single-step library.
A Library of text snippets, which is used with diff(1) to update
copies manually, semi-automatically or fully automatically.