= O =
one-liner wars n.
A game popular among hackers who code in
the language APL (see write-only language and line noise). The objective is to see who can code the most interesting
and/or useful routine in one line of operators chosen from APL's
exceedingly hairy primitive set. A similar amusement was
practiced among TECO hackers and is now popular among
Ken Iverson, the inventor of APL, has been credited with a
one-liner that, given a number N, produces a list of the
prime numbers from 1 to N inclusive. It looks like this:
(2 = 0 +.= T o.| T) / T <- iN
where `o' is the APL null character, the assignment arrow is a
single character, and `i' represents the APL iota.
Here's a Perl program that prints primes:
perl -wle '(1 x $_) !~ /^(11+)\1+$/ && print while ++ $_'
In the Perl world this game is sometimes called Perl Golf because
the player with the fewest (key)strokes wins.
--The Jargon File version 4.3.1, ed. ESR, autonoded by rescdsk.