package Role::Tiny;
-use strictures 1;
-use Class::Tiny::_Utils;
+sub _getglob { \*{$_[0]} }
+
+use strict;
+use warnings FATAL => 'all';
our %INFO;
our %APPLIED_TO;
our %COMPOSED;
+sub _load_module {
+ return 1 if $_[0]->can('can');
+ (my $proto = $_[0]) =~ s/::/\//g;
+ require "${proto}.pm";
+ return 1;
+}
+
sub import {
my $target = caller;
+ my $me = $_[0];
strictures->import;
+ return if $INFO{$target}; # already exported into this package
# get symbol table reference
my $stash = do { no strict 'refs'; \%{"${target}::"} };
# install before/after/around subs
foreach my $type (qw(before after around)) {
*{_getglob "${target}::${type}"} = sub {
+ require Class::Method::Modifiers;
push @{$INFO{$target}{modifiers}||=[]}, [ $type => @_ ];
};
}
};
*{_getglob "${target}::with"} = sub {
die "Only one role supported at a time by with" if @_ > 1;
- Role::Tiny->apply_role_to_package($_[0], $target);
- };
- *{_getglob "${target}::has"} = sub {
- my ($name, %spec) = @_;
- ($INFO{$target}{accessor_maker} ||= do {
- require Method::Generate::Accessor;
- Method::Generate::Accessor->new
- })->generate_method($target, $name, \%spec);
- $INFO{$target}{attributes}{$name} = \%spec;
+ $me->apply_role_to_package($target, $_[0]);
};
# grab all *non-constant* (ref eq 'SCALAR') subs present
# in the symbol table and store their refaddrs (no need to forcibly
}
sub apply_role_to_package {
- my ($me, $role, $to) = @_;
+ my ($me, $to, $role) = @_;
+
+ _load_module($role);
die "This is apply_role_to_package" if ref($to);
die "${role} is not a Role::Tiny" unless my $info = $INFO{$role};
*{_getglob "${to}::does"} = \&does_role;
}
- $me->_handle_constructor($to, $info->{attributes});
-
# copy our role list into the target's
@{$APPLIED_TO{$to}||={}}{keys %{$APPLIED_TO{$role}}} = ();
}
sub create_class_with_roles {
my ($me, $superclass, @roles) = @_;
+ die "No roles supplied!" unless @roles;
+
my $new_name = join('+', $superclass, my $compose_name = join '+', @roles);
return $new_name if $COMPOSED{class}{$new_name};
foreach my $role (@roles) {
+ _load_module($role);
die "${role} is not a Role::Tiny" unless my $info = $INFO{$role};
}
- require Class::Tiny::_mro;
- require Sub::Quote;
+ if ($] > 5.010) {
+ require mro;
+ } else {
+ require MRO::Compat;
+ }
my @composable = map $me->_composable_package_for($_), reverse @roles;
$new_name, $compose_name,
do { my %h; @h{map @{$_->{requires}||[]}, @info} = (); keys %h }
);
- $me->_handle_constructor(
- $new_name, { map %{$_->{attr_info}||{}}, @info }
- );
*{_getglob "${new_name}::does"} = \&does_role unless $new_name->can('does');
my $base_name = $composed_name.'::_BASE';
*{_getglob("${composed_name}::ISA")} = [ $base_name ];
my $modifiers = $INFO{$role}{modifiers}||[];
+ my @mod_base;
foreach my $modified (
do { my %h; @h{map $_->[1], @$modifiers} = (); keys %h }
) {
- Sub::Quote::quote_sub(
- "${base_name}::${modified}" => q{ shift->next::method(@_) }
- );
+ push @mod_base, "sub ${modified} { shift->next::method(\@_) }";
}
+ eval(my $code = join "\n", "package ${base_name};", @mod_base);
+ die "Evaling failed: $@\nTrying to eval:\n${code}" if $@;
$me->_install_modifiers($composed_name, $modifiers);
$COMPOSED{role}{$composed_name} = 1;
return $composed_name;
}
}
-sub _install_methods {
- my ($me, $to, $role) = @_;
-
+sub _concrete_methods_of {
+ my ($me, $role) = @_;
my $info = $INFO{$role};
-
- my $methods = $info->{methods} ||= do {
+ $info->{methods} ||= do {
# grab role symbol table
my $stash = do { no strict 'refs'; \%{"${role}::"}};
my $not_methods = $info->{not_methods};
} grep !(ref($stash->{$_}) eq 'SCALAR'), keys %$stash
};
};
+}
+
+sub methods_provided_by {
+ my ($me, $role) = @_;
+ die "${role} is not a Role::Tiny" unless my $info = $INFO{$role};
+ (keys %{$me->_concrete_methods_of($role)}, @{$info->{requires}||[]});
+}
+
+sub _install_methods {
+ my ($me, $to, $role) = @_;
+
+ my $info = $INFO{$role};
+
+ my $methods = $me->_concrete_methods_of($role);
# grab target symbol table
my $stash = do { no strict 'refs'; \%{"${to}::"}};
sub _install_modifiers {
my ($me, $to, $modifiers) = @_;
- foreach my $modifier (@{$modifiers||[]}) {
- _install_modifier($to, @{$modifier});
- }
-}
-
-sub _handle_constructor {
- my ($me, $to, $attr_info) = @_;
- return unless $attr_info && keys %$attr_info;
- if ($INFO{$to}) {
- @{$INFO{$to}{attributes}||={}}{keys %$attr_info} = values %$attr_info;
+ if (my $info = $INFO{$to}) {
+ push @{$info->{modifiers}}, @{$modifiers||[]};
} else {
- # only fiddle with the constructor if the target is a Class::Tiny class
- if ($INC{"Class/Tiny.pm"}
- and my $con = Class::Tiny->_constructor_maker_for($to)) {
- $con->register_attribute_specs(%$attr_info);
+ foreach my $modifier (@{$modifiers||[]}) {
+ $me->_install_single_modifier($to, @$modifier);
}
}
}
+sub _install_single_modifier {
+ my ($me, @args) = @_;
+ Class::Method::Modifiers::install_modifier(@args);
+}
+
sub does_role {
- my ($package, $role) = @_;
- return exists $APPLIED_TO{$package}{$role};
+ my ($proto, $role) = @_;
+ return exists $APPLIED_TO{ref($proto)||$proto}{$role};
}
1;
+
+=head1 NAME
+
+Role::Tiny - Roles. Like a nouvelle cusine portion size slice of Moose.
+
+=head1 SYNOPSIS
+
+ package Some::Role;
+
+ use Role::Tiny;
+
+ sub foo { ... }
+
+ sub bar { ... }
+
+ 1;
+
+else where
+
+ package Some::Class;
+
+ require Role::Tiny;
+
+ # bar gets imported, but not foo
+ Role::Tiny->apply_role_to_package('Some::Role', __PACKAGE__);
+
+ sub foo { ... }
+
+ 1;
+
+=head1 DESCRIPTION
+
+C<Role::Tiny> is a minimalist role composition tool.
+
+=head1 ROLE COMPOSITION
+
+Role composition can be thought of as much more clever and meaningful multiple
+inheritance. The basics of this implementation of roles is:
+
+=over 2
+
+=item *
+
+If a method is already defined on a class, that method will not be composed in
+from the role.
+
+=item *
+
+If a method that the role L</requires> to be implemented is not implemented,
+role application will fail loudly.
+
+Unlike L<Class::C3>, where the B<last> class inherited from "wins," role
+composition is the other way around, where first wins. In a more complete
+system (see L<Moose>) roles are checked to see if they clash. The goal of this
+is to be much simpler, hence disallowing composition of multiple roles at once.
+
+=head1 METHODS
+
+=head2 apply_role_to_package
+
+ Role::Tiny->apply_role_to_package('Some::Package', 'Some::Role');
+
+Composes role with package
+
+=head2 apply_roles_to_object
+
+ Role::Tiny->apply_roles_to_object($foo, qw(Some::Role1 Some::Role2));
+
+Composes roles in order into object directly. Object is reblessed into the
+resulting class.
+
+=head2 create_class_with_roles
+
+ Role::Tiny->create_class_with_roles('Some::Base', qw(Some::Role1 Some::Role2));
+
+Creates a new class based on base, with the roles composed into it in order.
+New class is returned.
+
+=head1 SUBROUTINES
+
+=head2 does_role
+
+ if (Role::Tiny::does_role($foo, 'Some::Role')) {
+ ...
+ }
+
+Returns true if class has been composed with role.
+
+This subroutine is also installed as ->does on any class a Role::Tiny is
+composed into unless that class already has an ->does method, so
+
+ if ($foo->does_role('Some::Role')) {
+ ...
+ }
+
+will work for classes but to test a role, one must use ::does_role directly
+
+=head1 IMPORTED SUBROUTINES
+
+=head2 requires
+
+ requires qw(foo bar);
+
+Declares a list of methods that must be defined to compose role.
+
+=head2 with
+
+ with 'Some::Role1';
+ with 'Some::Role2';
+
+Composes another role into the current role. Only one role may be composed in
+at a time to allow the code to remain as simple as possible.
+
+=head2 before
+
+ before foo => sub { ... };
+
+See L<< Class::Method::Modifiers/before method(s) => sub { ... } >> for full
+documentation.
+
+=head2 around
+
+ around foo => sub { ... };
+
+See L<< Class::Method::Modifiers/around method(s) => sub { ... } >> for full
+documentation.
+
+=head2 after
+
+ after foo => sub { ... };
+
+See L<< Class::Method::Modifiers/after method(s) => sub { ... } >> for full
+documentation.
+
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