File Coverage

blib/lib/With/Roles.pm

Criterion	Covered	Total	%
statement	83	95	87.3
branch	32	44	72.7
condition	22	48	45.8
subroutine	12	13	92.3
pod			n/a
total	149	200	74.5

package With::Roles;
use strict;
use warnings;

our $VERSION = '0.001001';
$VERSION =~ tr/_//d;

use Carp qw(croak);

my %COMPOSITE_NAME;
my %COMPOSITE_KEY;

my $role_suffix = 'A000';
sub _composite_name {
  my ($base, $role_base, @roles) = @_;
  my $key = join('+', $base, map join('|', @$_), @roles);
  return $COMPOSITE_NAME{$key}
    if exists $COMPOSITE_NAME{$key};

  my ($cut) = map qr/$_/, join '|', map quotemeta, @$role_base, $base;

  my $new_name = $base;
  for my $roles (@roles) {
    # this creates the potential for ambiguity, but it's unlikely to happen and
    # we will keep the resulting composite
    my @short_names = @$roles;
    for (@short_names) {
      s/\A${cut}::/::/;
      $_ = join '::',
        map { s/\W/_/g; $_ }
        split /::/;
    }
    $new_name .= '__WITH__' . join '__AND__', @short_names;
  }

  if ($COMPOSITE_KEY{$new_name} || length($new_name) > 252) {
    my $abbrev = substr $new_name, 0, 250 - length $role_suffix;
    $abbrev =~ s/(?
    $new_name = $abbrev.'__'.$role_suffix++;
  }

  $COMPOSITE_KEY{$new_name} = $key;

  return $COMPOSITE_NAME{$key} = $new_name;
}

sub _gen {
  my ($pack, $type, @ops) = @_;
  my $e;
  {
    local $@;
    no strict 'refs';
    local *{"${pack}::${_}"}
      for qw(with extends requires has around after before);

    my $code = join('',
      "package $pack;\n",
      (defined $type ? "use $type;\n" : ()),
      (
        map "$ops[$_-1](\@{\$ops[$_]});\n",
        map $_*2+1,
        0 .. (@ops/2-1)
      ),
      "1;\n",
    );

    eval $code or $e = $@;
  }
  die $e if defined $e;
}

sub _require {
  my $package = shift;
  (my $module = "$package.pm") =~ s{::|'}{/}g;
  require $module;
}

sub _extends {
  no strict 'refs';
  my $caller = caller;
  @{"${caller}::ISA"} = (@_);
  _copy_mro($_[0], $caller);
}

sub _copy_mro {
  my $source = shift;
  my $target = shift || caller;
  mro::set_mro($target, mro::get_mro($source))
    if defined &mro::set_mro;
}

sub _detect_type {
  my ($base, @roles) = @_;
  my $meta;
  if (
    $INC{'Moo/Role.pm'}
    and Moo::Role->is_role($base)
  ) {
    return 'Moo::Role';
  }
  elsif (
    $INC{'Moo.pm'}
    and Moo->_accessor_maker_for($base)
  ) {
    return 'Moo';
  }
  elsif (
    $INC{'Class/MOP.pm'}
    and $meta = Class::MOP::class_of($base)
    and $meta->isa('Moose::Meta::Role')
  ) {
    return 'Moose::Role';
  }
  elsif (
    $INC{'Class/MOP.pm'}
    and $meta = Class::MOP::class_of($base)
    and $meta->isa('Class::MOP::Class')
  ) {
    return 'Moose';
  }
  elsif (
    defined &Mouse::Util::find_meta
    and $meta = Mouse::Util::find_meta($base)
    and $meta->isa('Mouse::Meta::Role')
  ) {
    return 'Mouse::Role';
  }
  elsif (
    defined &Mouse::Util::find_meta
    and $meta = Mouse::Util::find_meta($base)
    and $meta->isa('Mouse::Meta::Class')
  ) {
    return 'Mouse';
  }
  elsif (
    $INC{'Role/Tiny.pm'}
    and Role::Tiny->is_role($base)
  ) {
    return 'Role::Tiny';
  }
  else {
    local $@;
    eval { _require($_) }
      for grep !($INC{'Role/Tiny.pm'} && Role::Tiny->is_role($_)), @roles;
    if (
      $INC{'Role/Tiny.pm'}
      and !grep !Role::Tiny->is_role($_), @roles
    ) {
      return 'Role::Tiny::With';
    }
    else {
      return undef;
    }
  }
}

my %BASE;
sub with::roles {
  my ($self, @roles) = @_;
  return $self
    if !@roles;

  my $base = ref $self || $self;

  my ($orig_base, @base_roles) = @{ $BASE{$base} || [$base] };

  my $role_base = $self->can('ROLE_BASE') ? $self->ROLE_BASE : $orig_base.'::Role';

  s/\A\+/${role_base}::/ for @roles;

  my @all_roles = (@base_roles, [ @roles ]);

  my $new = _composite_name($orig_base, [ $role_base ], @all_roles);

  if (!exists $BASE{$new}) {
    my $type = _detect_type($base, @roles)
      or croak "Can't determine class or role type of $base or @roles!";

    my @ops;

    if ($type eq 'Role::Tiny::With') {
      push @ops, __PACKAGE__.'::_extends', [ $base ];
    }
    elsif ($type =~ /Role/) {
      push @ops, with => [ $base ];
    }
    else {
      push @ops, extends => [ $base ];
      push @ops, __PACKAGE__.'::_copy_mro' => [ $base ];
    }

    push @ops, with => [ @roles ];

    _gen($new, $type, @ops);
  }

  $BASE{$new} = [$orig_base, @all_roles];

  if (ref $self) {
    # using $_[0] rather than $self, to work around how overload magic is
    # applied on perl 5.8
    return bless $_[0], $new;
  }

  return $new;
}

1;
__END__