Combinations
AUTHOR
Eric Hodges
Specification:
From http://www.perlmonks.org/?node_id=731808
Given a list of URL prefixes, and a list of product IDs, make a list consisting of each URL prefix concatenated with each product ID.
use v6;
my @urls = ('http://www.something.com/blah.aspx?code=',
'http://www.somethingelse.com/stuff.aspx?thing=');
my @ids = <375035304 564564774 346464646>;
# 1. Cross then map
# We use the cross operator X to make every combination of pairs from @urls
# and @ids. We then use map to stringify each pair. $^a is a "placeholder
# argument" - in this case, it refers to the only argument to the block.
my @combined = (@urls X @ids).map: { ~$^a };
.say for @combined;
# 2. cross hyperoperator
# We use the cross hyperoperator X~
# This combines each element from list1 with each element from list2 using ~
# You can use any infix operator.
# Try (1,2,3) X* (1,2,3) to generate a multiplication table.
.say for @urls X~ @ids;
# vim: expandtab shiftwidth=4 ft=perl6