mro

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

Perl equivalent: mro (XS core module)

Functions

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

set_mro

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

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

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');

invalidate_all_method_caches

Clears the entire CV cache without targeting a specific class.

use mro;
mro::invalidate_all_method_caches();

import

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

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