# 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.

```none
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"`.

```none
use mro;
mro::set_mro('MyClass', 'c3');
```

## get_mro

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

```none
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).

```none
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.

```none
use mro;
my $gen = mro::get_pkg_gen('MyClass');
```

## is_universal

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

```none
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.

```none
use mro;
mro::method_changed_in('MyClass');
```

## invalidate_all_method_caches

Clears the entire CV cache without targeting a specific class.

```none
use mro;
mro::invalidate_all_method_caches();
```

## import

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

```none
use mro 'c3';  # sets C3 for current package
```