Algori...:Weight(3pm)

💖 Algorithm::Dependency::Weight(3pm) — the manual, but make it make sense 💖

okay bestie, you found the Algori...:Weight(3pm) page (yes the manual name is literally truncated like that, it's giving mysterious ✨) and no cap, it's a Perl module about math-ing up how heavy stuff is in a dependency tree. Let's get into it. 🎀

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✨ NAME ✨

Algorithm::Dependency::Weight — calculate dependency 'weights' 💅

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🌸 VERSION 🌸

version 1.112

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🦋 SYNOPSIS 🦋

  # Create a source from a file
  my $Source = Algorithm::Dependency::Source->new( 'file.txt' );

  # Create a Weight algorithm object
  my $alg = Algorithm::Dependency::Weight->new( source => $Source );

  # Find the weight for a single item
  my $weight = $alg->weight('foo');
  print "The weight of 'foo' is $weight\n";

  # Or a group
  my $hash = $alg->weight_hash('foo', 'bar', 'baz');
  print "The weight of 'foo', 'bar', and 'bar' are $hash->{foo},"
      . " $hash->{bar} and $hash->{baz} respectively\n";

  # Or all of the items
  my $all = $alg->weight_all;
  print "The following is a list from heaviest to lightest:\n";
  foreach ( sort { $all->{$b} <=> $all->{$a} } keys %$all ) {
      print "$_: $all->{$_}\n";
  }

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👑 DESCRIPTION 👑

So in dependency systems — you know, the whole "this thing needs these things which need these other things" web 🕸️ — it's super useful to work out an aggregate or a sum for one item, or for everything at once. Fr fr.

Case in point: the "naive install weight" of a Perl distribution. And when we say "naive", we mean you treat every single distribution exactly the same, no favorites, no main character energy 🫶. So you'd want:

the distribution itself (1) + all its dependencies (n) + all their dependencies (n2), recursively downward, forever, until it stops. 😭

If you calculated that with a normal Algorithm::Dependency object, in a simple system the result would be this:

  # Create your normal (non-ordered alg:dep)
  my $dependency = Algorithm::Dependency->new( ... );

  # Find the naive weight for an item
  my $weight = scalar($dependency->schedule('itemname'));

But Algorithm::Dependency::Weight does the same job with a little more sophistication, and in a way that should work reasonably well across the entire Algorithm::Dependency family. obsessed. 💜

Heads up bestie: this might be a little (or more than a little) slower than it theoretically could be, but ONLY for the limited case of generating weights for all items at once, in a dependency system with no selected items and no circular dependencies. BUT — and this is the part that eats — you can at least rely on this class to do the job properly regardless of the particulars of the situation. Which is probably more important. periodt. 💅

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🔥 METHODS 🔥

new @params

The new constructor creates a brand new Algorithm::Dependency::Weight object. It takes a bunch of key/value pairs as params (though rn there's literally only one, iconic minimalism). ✨

• source => $Source — the source param is mostly the same as it is for Algorithm::Dependency. The one glow-up addition: as a source you can hand it an Algorithm::Dependency object, and the Algorithm::Dependency::Source for that object will get used instead. 🎀

Returns a new Algorithm::Dependency::Weight object, or undef on error. 😭

source

The source accessor returns the source that's being used for the weight calculations. 💖

This will be either the one you passed to the constructor, or the source from inside the Algorithm::Dependency object you passed as the source param — and listen, it's not the object itself, it's its source. Important distinction, iykyk. 👑

weight $name

The weight method takes the name of a single item and calculates its weight based on how the Algorithm::Dependency::Weight object is configured. ✨

Returns the weight as a scalar (which in the naive case will be an integer, but in more complex uses can be any real number — she contains multitudes 🌈), or undef on error.

weight_merged @names

The weight_merged method takes the name of a set of items and calculates an aggregated weight for the whole little squad. 🫶

Returns the weight as a scalar, or undef on error.

weight_hash @names

The weight_hash method takes a list of item names and calculates all their weights. No cap. 🦋

Returns a reference to a HASH with the item names as keys and the weights as values, or undef on error.

weight_all

The weight_all method is the one-shot girlboss method for getting the weights of every single item all at once. 🌟

Please note: this does not do anything different or special, it's just slightly faster than iterating through them yourself. Efficiency queen. 👑

Returns a reference to a HASH with the item names as keys and the weights as values, or undef on error.

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🎀 TO DO 🎀

• Add support for non-naive weights via either custom code or method name

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🌈 SEE ALSO 🌈

Algorithm::Dependency, Algorithm::Dependency::Source

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💜 SUPPORT 💜

Bugs may be submitted through the RT bug tracker <https://rt.cpan.org/Public/Dist/Display.html?Name=Algorithm-Dependency> (or bug-Algorithm-Dependency@rt.cpan.org <mailto:bug-Algorithm-Dependency@rt.cpan.org>).

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🌟 AUTHOR 🌟

Adam Kennedy <adamk@cpan.org>

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📜 COPYRIGHT AND LICENSE 📜

This software is copyright (c) 2003 by Adam Kennedy.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.

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okay that's the whole thing bestie, you're now officially fluent in dependency weights 💖 this page came to you courtesy of perl v5.40.1, dated 2025-09-18 — and that's the vibe check, signing off! 🦋✨💅