in reply to Sort list by position of items in another list

I would say this is a radix sort: 
my $pchr = "KQRBNP";
my $w1 = "QRKPNBNBQRK";

my %s;
$s{$_}++ for split //, $w1;
my $w2 = $pchr =~ s/(.)/$1 x $s{$1}/egr;

print "$w1 -> $w2\n"

[download]

Replies are listed 'Best First'.
Re^2: Sort list by position of items in another list
by rsFalse (Chaplain) on Feb 20, 2022 at 20:13 UTC
    Similar to yours and choroba's solutions but without string multiplication ('x'): 
    my $pchr = "KQRBNP";
my $w1 = "QRKPNBNBQRK";
my $w2 = "";

for my $L ( split //, $pchr ){
  $w1 =~ m/$L(?{ $w2 .= $L })(*FAIL)/;
}

print "$w1 -> $w2\n"

    [download]
    And a bit similar to drclaw's idea: 
    my $pchr = "KQRBNP";
my $w1 = "QRKPNBNBQRK";
my $w2 = "";

my $re = join "|", map { ".*$_" } split //, $pchr;
$w1 =~ m/^(?:$re)(?<=(.))(?{ $w2 .= $1 })(*FAIL)/;

print "$w1 -> $w2\n"

    [download]
    Not sure if regex is optimized in some versions and this code fails.
[reply]
[d/l]
[select]

In Section Seekers of Perl Wisdom