A while back, I wrote Fun with join. I think it's great that you have a possible use for it. :-)

Alternatively, you could use List::Util 'reduce' to roll your own version of join that does the same thing. 

use List::Util 'reduce';

my @arr = ('A'..'L');
my $per_line = 2;
my $on_this_line = 0;
print reduce {$a . (++$on_this_line % $per_line ? ',' : "\n") . $b} @a
+rr;

[download]
or 
my @arr = ('A'..'L');
my $sep = [',', "\n"];
print reduce {$a . ($sep->[@$sep] = shift @$sep) . $b} @arr;

[download]
The last works, though it's possibly too clever. What if the left @$sep is evaluated before the shift?
Caution: Contents may have been coded under pressure.

In reply to Re: how to alternate join? by Roy Johnson
in thread how to alternate join? by SamCG

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