Re^2: New Alphabet Sort Order

[Polyglot]

Khen, thank you for the tip. I took a look at that and asked up the line about it. I guess many people in Laos still use that font system. However, for this project, we are intending to use unicode. Unicode still seems a bit new to Lao, so it will not be without some difficulties. But we feel it may be the best and most future-compatible standard to follow.

[furry_marmot]

Polyglot,

I think BrowserUK's solution is the direction you'll end up going. The ST and GRT he referred to are the Schwartzian Transform and Guttman Rosler Transform, respectively. You only need the first.

The link explains it, but basically you transform a list of things you want to sort into a list of two-element arrays. The first element is the key, set up so you can easily sort it. The second is the original element, untouched. You can do it in separate steps, but the transform is more efficient if you have a lot of elements. The key thing you need is a function that can create a function that will create a key that you can sort on.

Here's an example, sorting movie names, done separately first.

use Lingua::EN::Numbers qw(num2en);
sub make_key {
  $_ = shift;
  s/^(?:The|An|A) // || s/^[^A-Z_]+(\d+)/num2en;
  return $_;
}

my @movies = (
  '(500) Days of Summer',            # F for Five hundred
  'The Music Man',                   # M for Music
  'The Good, the Bad, and the Ugly'  # G for Good
);

my @tmp = ();
for (@movies) {
  push @tmp [ make_key($_), $_ ]     # 2-element anonymous array
}

@tmp = sort { $a->[0] cmp $b->[0] } @tmp; # sort on first elements

@movies = map { $_->[1] } @tmp;      # pull off second element from ea
+ch
                                     # anonymous array
print "$_\n" for @movies;

__END__
Prints:

(500) Days of Summer
The Good, the Bad, and the Ugly
The Music Man

Now, MUCH less complicated:

use Lingua::EN::Numbers qw(num2en);
sub make_key {
  $_ = shift;
  s/^(?:The|An|A) // || s/^[^A-Z_]+(\d+)/num2en;
  return $_;
}

my @movies = (
  '(500) Days of Summer',            # F for Five hundred
  'The Music Man',                   # M for Music
  'The Good, the Bad, and the Ugly'  # G for Good
);

# Here's the transform. Read from the bottom up.
my @movies =                    # original elements replaced with same
+, but sorted
  map  { $_->[1] }              # pull off second element from each
  sort { $a->[0] cmp $b->[0] }  # sort arrays on first elements
  map  { [ make_key($_), $_ ] } # 2-element anonymous array becomes ne
+w $_
@movies;

print "$_\n" for @movies;

__END__
Prints:

(500) Days of Summer
The Good, the Bad, and the Ugly
The Music Man

Good luck!

--marmot

UPDATE: Corrected a typo bug in the ST that came from copying the first version.