If you don't want the spaces, don't put them in to start with. Rather than "@$_" use join'',@$_ or pack 'A*', @$_, or set $"=undef.

Of course I picked the slowest way(s) not to do it. I've got a bad habit of overthinking problems and overengineering solutions and shoving a regex into map like that when I know all about join is typical! Your keisaku is appreciated, I can see:

map + regex: ~0m0.950s 
time perl -MAlgorithm::Combinatorics=:all -wle'
my $i=variations_with_repetition(["a".."z"],$ARGV[0]); 
my @x; push @x, map {s/ //} qq[@$_] while $_=$i->next; 
print scalar @x' 4

[download]
map: ~0m0.830s 
time perl -MAlgorithm::Combinatorics=:all -wle'
my $i=variations_with_repetition(["a".."z"],$ARGV[0]); 
my @x; push @x, map {$_} qq[@$_] while $_=$i->next; 
print scalar @x' 4

[download]
pack: ~0m0.820s 
time perl -MAlgorithm::Combinatorics=:all -wle'
my $i=variations_with_repetition(["a".."z"],$ARGV[0]); 
my @x; push @x, pack "A*", qq[@$_] while $_=$i->next; 
print scalar @x' 4

[download]
join: ~0m0.720s 
time perl -MAlgorithm::Combinatorics=:all -wle'
my $i=variations_with_repetition(["a".."z"],$ARGV[0]); 
my @x; push @x, join "", @$_ while $_=$i->next; 
print scalar @x' 4

[download]
$"=undef: ~0m0.720s 
time perl -MAlgorithm::Combinatorics=:all -le'
my $i=variations_with_repetition(["a".."z"],$ARGV[0]); 
my @x; qq[$"=undef]; push @x, qq[@$_] while $_=$i->next; 
print scalar @x' 4

[download]
STOP REINVENTING WHEELS, START BUILDING SPACE ROCKETS!—CPAN 🐫

In reply to Re^6: list of four digit lock combinations without repeated digits by usemodperl
in thread list of four digit lock combinations without repeated digits by Lotus1

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