Right-to-left (was: Re: entry at other than main)

[Scott Schwartz]

Henry Spencer writes:
| Dolf Grunbauer writes:
| >For those unknown to APL: do you know that APL is so compact that an
| >algorithm to get the first N primes can be written in just *ONE* expression
| >(of about 25 characters), including the reading of N from the terminal ?
| 
| Yes, and a month afterward, even its author can't understand it without
| half an hour of study.

Just for fun, here it is:

	P <- (2=+ /- 0=(iN)o.|iN)/iN

Where "<-" and "/-" are overstruck, "i" is iota, and "o" is the
little open circle.  It takes about 10 minutes to read the page long
explaination in the handout I copied the expression from.

Believe it or not, I once had a physics professor who went through
"The C Programming Language" and translated some of the examples into
APL, and scribbled them in the margins.  Now _that_ was scary.



--
Scott Schwartz		<schwartz at shire.cs.psu.edu>