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📖 NAME

CPAN::Meta::Prereqs — a set of distribution prerequisites by phase and type

🚀 Quick Reference

Use Case	Command	Description
📦 Create empty prereqs	CPAN::Meta::Prereqs->new	Returns an empty set of prerequisites for incremental building
🔍 Get requirements for a phase/type	$prereqs->requirements_for($phase, $type)	Returns a CPAN::Meta::Requirements object for the given phase/type
📋 List all phases	$prereqs->phases	Returns all phases currently populated
🔬 List types in a phase	$prereqs->types_in('runtime')	Returns all types in a given phase
🔗 Merge prereqs from another object	$prereqs->with_merged_prereqs($other)	Returns a new object with merged prereqs (e.g., core + feature)
🧩 Merge requirements across phases/types	$prereqs->merged_requirements(\@phases, \@types)	Joins requirements into a single CPAN::Meta::Requirements
📄 Convert to plain hash	$prereqs->as_string_hash	Returns a hashref suitable for dumping into distmeta
🔒 Finalize prereqs	$prereqs->finalize	Locks the object against further modification
📝 Clone prereqs	$prereqs->clone	Returns a modifiable copy (finalization not preserved)

📚 VERSION

version 2.150010

📝 DESCRIPTION

A CPAN::Meta::Prereqs object represents the prerequisites for a CPAN distribution or one of its optional features. Each set of prereqs is organized by phase and type, as described in CPAN::Meta::Prereqs.

🛠️ METHODS

🏗️ new

my $prereq = CPAN::Meta::Prereqs->new( \%prereq_spec );

This method returns a new set of Prereqs. The input should look like the contents of the prereqs field described in CPAN::Meta::Spec, meaning something more or less like this:

my $prereq = CPAN::Meta::Prereqs->new({
  runtime => {
    requires => {
      'Some::Module' => '1.234',
      ...,
    },
    ...,
  },
  ...,
});

You can also construct an empty set of prereqs with:

my $prereqs = CPAN::Meta::Prereqs->new;

This empty set of prereqs is useful for accumulating new prereqs before finally dumping the whole set into a structure or string.

🔍 requirements_for

my $requirements = $prereqs->requirements_for( $phase, $type );

This method returns a CPAN::Meta::Requirements object for the given phase/type combination. If no prerequisites are registered for that combination, a new CPAN::Meta::Requirements object will be returned, and it may be added to as needed.

If $phase or $type are undefined or otherwise invalid, an exception will be raised.

📋 phases

my @phases = $prereqs->phases;

This method returns the list of all phases currently populated in the prereqs object, suitable for iterating.

🔬 types_in

my @runtime_types = $prereqs->types_in('runtime');

This method returns the list of all types currently populated in the prereqs object for the provided phase, suitable for iterating.

🔗 with_merged_prereqs

my $new_prereqs = $prereqs->with_merged_prereqs( $other_prereqs );

my $new_prereqs = $prereqs->with_merged_prereqs( \@other_prereqs );

This method returns a new CPAN::Meta::Prereqs object in which all the other prerequisites given are merged into the current set. This is primarily provided for combining a distribution's core prereqs with the prereqs of one of its optional features.

The new prereqs object has no ties to the originals, and altering it further will not alter them.

🧩 merged_requirements

my $new_reqs = $prereqs->merged_requirements( \@phases, \@types );
my $new_reqs = $prereqs->merged_requirements( \@phases );
my $new_reqs = $prereqs->merged_requirements();

This method joins together all requirements across a number of phases and types into a new CPAN::Meta::Requirements object. If arguments are omitted, it defaults to runtime, build and test for phases and requires and recommends for types.

📄 as_string_hash

This method returns a hashref containing structures suitable for dumping into a distmeta data structure. It is made up of hashes and strings, only; there will be no Prereqs, CPAN::Meta::Requirements, or version objects inside it.

🔒 is_finalized

This method returns true if the set of prereqs has been marked finalized, and cannot be altered.

🔒 finalize

Calling finalize on a Prereqs object will close it for further modification. Attempting to make any changes that would actually alter the prereqs will result in an exception being thrown.

📝 clone

my $cloned_prereqs = $prereqs->clone;

This method returns a Prereqs object that is identical to the original object, but can be altered without affecting the original object. Finalization does not survive cloning, meaning that you may clone a finalized set of prereqs and then modify the clone.

🐛 BUGS

Please report any bugs or features using the CPAN Request Tracker. Bugs can be submitted through the web interface at http://rt.cpan.org/Dist/Display.html?Queue=CPAN-Meta

When submitting a bug or request, please include a test-file or a patch to an existing test-file that illustrates the bug or desired feature.

👤 AUTHORS

• David Golden <dagolden AT cpan.org>
• Ricardo Signes <rjbs AT cpan.org>
• Adam Kennedy <adamk AT cpan.org>

📜 COPYRIGHT AND LICENSE

This software is copyright (c) 2010 by David Golden, Ricardo Signes, Adam Kennedy and Contributors.

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

perl v5.34.0 — 2026-06-23 — CPAN::Meta::Prereqs(3perl)

📖 NAME 🚀 Quick Reference 📚 VERSION 📝 DESCRIPTION 🛠️ METHODS 🐛 BUGS 👤 AUTHORS 📜 COPYRIGHT AND LICENSE