[Purdue-pm] sexy primes, etc.

[Mark Senn]

Perl Weekly Challenge 022, Task #1:

    Write a script to print first 10 Sexy Prime Pairs. Sexy primes are prime
    numbers that differ from each other by 6. For example, the numbers 5 and
    11 are both sexy primes, because 11 - 5 = 6. The term “sexy prime” is a
    pun stemming from the Latin word for six: sex.

See
    https://engineering.purdue.edu/~mark/pwc-022-1.pdf
for my solution using a circular buffer of two elements using Perl 6.
A description of why only two elements are needed is my blog entry.

Some neat Perl 6 stuff:

    # This is a loop that generates primes one at a time
    ((2.. Inf).grep ({.is -prime })) {

    # Is the numeric variable $var is in the array @a one or more times?
    # There is also "one" for occurs one time, and "none" for zero times.
    if ($var == @a.any) {

    if ($a %% $b) {  # do following block if $a mod $b is zero

    if ($a < $b < $c) {  # is $a < $b and $b < $c?

    is ([<=] @array) {  # is @array sorted numerically

    say ([+] @array) / @array.elems;  # print average of @array

One think I wish Perl 6 did (Wolfram Language (Mathematica) does it):
scalar times array = array

    2 * (1,2) gives (2,4) in a world I want t live in

But one can overload all built in operators depending on their types
to do different things.  I think this can be done easily in Perl
but a separate definition would need to be done for + - * / etc.

-mark