Re^2: Sort list by position of items in another list


Keep It Simple, Stupid
	PerlMonks

Re^2: Sort list by position of items in another list

by rsFalse (Chaplain)

on Feb 20, 2022 at 20:13 UTC ( [id://11141522]=note: print w/replies, xml )

Need Help??

in reply to Re: Sort list by position of items in another list
in thread Sort list by position of items in another list

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.