Re^2: Sorting files by 3 numbers in the name

[LanX]

FWIW it's certainly faster your way, but personally I'd rather go for named matches, for the sake of readability.

See %+ in perlretut#Named-backreferences . :)

[tobyink]

Yeah, but I think they were added in 5.10, and when possible I try to give examples using 5.8 features. (Something like say is excusable, because it's so easy to write a shim for it.

sub say { local $\ = "\n"; print(@_ or $_) }
sub IO::Handle::say { my $h = shift; local $\ = "\n"; $h->print(@_ or 
+$_) }

I also quite like this way:

use constant {
    IX_FILENAME => 0,
    IX_RUN      => 2,
    IX_DISTRICT => 8,
    IX_COPY     => 9,
    IX_TOTAL    => 10,
};

print Dumper 
    map {
        Dumper($_), $_->[IX_FILENAME]
    }
    sort {
        $a->[IX_RUN]      <=> $b->[IX_RUN]       or
        $a->[IX_DISTRICT] <=> $b->[IX_DISTRICT]  or
        $a->[IX_COPY]     <=> $b->[IX_COPY]      or
        $a->[IX_TOTAL]    <=> $b->[IX_TOTAL]        
    }
    map {
        [ $_, split /_/ ]
    }
    @files;

[LanX]

agreed, with split it's a plus! =)

I wonder about the best idiomatic way ( with or w/o List::Util ) to shorten the or chain such that we don't need to repeat the field names.

use strict;
use warnings;
use Data::Dump;
use List::Util qw/first/;
$\="\n";

# --- init

my @fields = qw( RUN DISTRICT COPY TOTAL );

my %a = map { $_ => 1- int rand 3  } @fields;
my %b = map { $_ => 1- int rand 3  } @fields;

dd \@fields,\%a,\%b;

# ---  w/o List::Util

my $last;
my $field;

for (@fields) {
   $field =$_;
   $last = $a{$_} <=> $b{$_}  and last;
}

print "$field,$last";

# ---  with List::Util


print first { $last = $a{$_} <=> $b{$_} } @fields;
print $last;

(
  ["RUN", "DISTRICT", "COPY", "TOTAL"],
  { COPY => -1, DISTRICT => 1, RUN => 1, TOTAL => -1 },
  { COPY => -1, DISTRICT => 1, RUN => 1, TOTAL => 0 },
)

TOTAL,-1
TOTAL
-1