Finally, one line, and no experimental features! 

sub double_it {
   return join ' ', $_[0] =~ /\w(?=\w(?<=(..)))/g;
}

[download]

Alternate versions: 

sub double_it {
   local ($_) = @_;

   (my @chars1) = (my @chars2) = split //;
   pop   @chars1;
   shift @chars2;

   return join ' ',
          grep { !/\s/ }
          map { $chars1[$_] . $chars2[$_] }
          0..$#chars1;
}

[download]
sub double_it {
   local ($_) = @_;

   my @list = /(\w)(?=(\w))/g;

   my @pairs;
   push(@pairs, shift(@list).shift(@list))
      while @list;

   return join(' ', @pairs);
}

[download]
sub double_it {
   our @pairs; local *pairs;
   () = $_[0] =~ /(\w)(?=(\w))(?{ push(@pairs, "$1$2"); })/g;
   return join(' ', @pairs);
}

[download]

In reply to Re: Splitting a string by ikegami
in thread Splitting a string by lampros21_7

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