Conway: Infinite work is less work

Post Syndicated from corbet original https://lwn.net/Articles/793441/rss

Damian Conway writes
about the power of infinite sequences
in Perl 6.

The sequence of primes is just the sequence of positive integers,
filtered (with a .grep) to keep only the ones that are prime.
And, of course, Perl 6 already has a prime number tester: the built-in
&is-prime function. The sequence of primes never changes, so we can
declare it as a constant:

    constant p = [  (1..∞).grep( &is-prime )  ];

Now we need to extract just the strong and weak primes.