mro

Native Rust implementation built into the interpreter. Runtime: PP. See original documentation for the full Perl reference.

MRO (Method Resolution Order) implementation

Provides DFS and C3 linearization of class hierarchies, matching the behaviour of perl5’s mro core module (mro.xs).

Public API:

• get_linear_isa(class [, "dfs"|"c3"]) — recursive linearization
• set_mro(class, "dfs"|"c3") — per-class MRO preference
• get_mro(class) — return stored preference (default “dfs”)
• get_isarev(class) — reverse @ISA index (computed on-the-fly)
• get_pkg_gen(class) — generation counter (per-package, real tracking)
• is_universal(class) — true only for “UNIVERSAL”
• method_changed_in / invalidate_all_method_caches — cache invalidation

Functions

get_isarev

Returns an arrayref of classes that directly or indirectly inherit from the given class (reverse @ISA index, computed on the fly).

use mro;
my $subclasses = mro::get_isarev('BaseClass');

get_linear_isa

Returns the linearized @ISA for a class using DFS (default) or C3 algorithm.

use mro;
my $isa = mro::get_linear_isa('MyClass');        # DFS
my $isa = mro::get_linear_isa('MyClass', 'c3');  # C3

get_mro

Returns the stored MRO algorithm name for a class (defaults to "dfs").

use mro;
my $type = mro::get_mro('MyClass');  # "dfs" or "c3"

get_pkg_gen

Returns the per-package generation counter. Bumped on each define_sub or method_changed_in call. Returns 0 for non-existent packages, 1 for packages with no explicit counter yet.

use mro;
my $gen = mro::get_pkg_gen('MyClass');

import

Called implicitly by use mro 'c3'. Sets the MRO algorithm for the calling package.

use mro 'c3';  # sets C3 for current package

invalidate_all_method_caches

Clears the entire CV cache without targeting a specific class.

use mro;
mro::invalidate_all_method_caches();

is_universal

Returns true only if the given class is "UNIVERSAL".

use mro;
my $ok = mro::is_universal('UNIVERSAL');  # 1

method_changed_in

Bumps the generation counter for the given class and invalidates all CV caches. Call when method resolution may have changed.

use mro;
mro::method_changed_in('MyClass');

set_mro

Sets the MRO algorithm for a class. Valid values: "dfs", "c3".

use mro;
mro::set_mro('MyClass', 'c3');