obfuscated
ambrus
<p>
The language designer said to the programmer: “Thank you for freeing me from my prejudices. I understand now that a language must not try to force the programmers to follow any single paradigm, but should instead offer all the features the programmer may want to use. As a reward, you may wish for any three features and I will add them to the language.”
<p>
The programmer replied: “I'd like a powerful domain-specific language for blowing up binary strings to small parts.”
<p>
The language designer granted the programmer's wish, and the programmer promptly tried it, saying
<code>
#!perl
use warnings; use strict; use 5.010;
use Time::HiRes "sleep";
our $DELAY = 0.05;
# determine size of terminal
my $w = pack "S4", 24, 79;
ioctl STDIN, $_, $w for 0x40087468, 0x5413;
our($R, $C) = unpack "S2", $w; $R--;
our $b;
if (rand 3 < 1) {
# glider gun pattern
$b = pack "(A$C)[Lx$R]", ("")x3, split /^/, "
1
1 1
11 11 11
1 1 11 11
11 1 1 11
11 1 1 11 1 1
1 1 1
1 1
11 ";
} else {
# generate random bitmap as starting state
$b = pack "(A)*", map { rand 3 < 1 } 0 .. 2*$R*$C;
}
system qw"tput clear";
while () {
# display game board
system qw"tput home";
say for unpack "xx$C(a$C)$R", $b;
sleep $DELAY;
# game of life evolution step
no warnings "numeric";
$b =
pack "xx$C(A)*xx$C",
unpack "(x7a/(x13)X4Ax!18)[(A$R)$C]",
pack "((a*)17xx!18)*x3",
unpack "((AAAX3AAA\@$C AXAAAXAx$C (X3AAA)2\@)$C)$R",
$b;
}
__END__
</code>
<p>
The programmer watched the pretty patterns appearing in his terminal.
<p>
After a while, the language designer asked “And your other wishes?”
<p>
The programmer's reply was “Why would I need other wishes?”
<readmore title="Remarks">
<hr>
<p>
Remarks.
<ol>
<li>
The story is stolen from [http://xkcd.com/152/|xkcd strip 152: Hamster Ball], reinterpreted slightly.
<li>
In case you can't guess from the comments, this obfuscation shows the evolution of Conway's Game of Life cellular automaton, starting from either a completely random pattern or a fixed glider gun pattern. The program runs forever, stop it with control-C if you get bored, then restart to get another random pattern or the glider gun.
<li>
It may be worth to resize your terminal to larger so that you get a larger game board.
<li>
The glider gun also serves as an example to show how to edit the program to start from a pattern of your choice.
<li>
It is possible that the dialog is internal, the language designer and the programmer being just different aspects of the same person.
<li>
The programmer has used the word “explode”, but the language designer took liberty to name the feature “unpack” instead to avert [http://mathoverflow.net/questions/53122/mathematical-urban-legends/53738#53738|curious incidents in case programmers obliviously discuss the feature in an airport waiting room]. He was thus wiser than the designers of Standard ML, as that language has a function named <c>explode</c> to blow a string to pieces.
<li>
I have already known from my previous obfuscations that the power of unpack is easy to abuse: unpack can [id://933656|follow a linked list], [id://908680|generate the list of suffixes of a string], [id://863110|aid in arithmetic over a finite field], or (Update) [id://835076|drive a quine].
<li>
The evolution step on the whole board is implemented as just two calls to unpack and two calls to pack. Is it possible to use even fewer calls?
</ol>
</readmore>