use strict;
use warnings FATAL => 'all';
-our $VERSION = '1.000001'; # 1.0.1
+our $VERSION = '1.001002'; # 1.1.2
$VERSION = eval $VERSION;
our %INFO;
our %APPLIED_TO;
our %COMPOSED;
+our %COMPOSITE_INFO;
# Module state workaround totally stolen from Zefram's Module::Runtime.
*{_getglob "${target}::${type}"} = sub {
require Class::Method::Modifiers;
push @{$INFO{$target}{modifiers}||=[]}, [ $type => @_ ];
+ return;
};
}
*{_getglob "${target}::requires"} = sub {
push @{$INFO{$target}{requires}||=[]}, @_;
+ return;
};
*{_getglob "${target}::with"} = sub {
- $me->apply_union_of_roles_to_package($target, @_);
+ $me->apply_roles_to_package($target, @_);
+ return;
};
# grab all *non-constant* (stash slot is not a scalarref) subs present
# in the symbol table and store their refaddrs (no need to forcibly
# inflate constant subs into real subs) - also add '' to here (this
- # is used later)
- @{$INFO{$target}{not_methods}={}}{
- '', map { *$_{CODE}||() } grep !ref($_), values %$stash
- } = ();
+ # is used later) with a map to the coderefs in case of copying or re-use
+ my @not_methods = ('', map { *$_{CODE}||() } grep !ref($_), values %$stash);
+ @{$INFO{$target}{not_methods}={}}{@not_methods} = @not_methods;
# a role does itself
$APPLIED_TO{$target} = { $target => undef };
}
-sub apply_role_to_package {
+sub apply_single_role_to_package {
my ($me, $to, $role) = @_;
_load_module($role);
die "No roles supplied!" unless @roles;
+ {
+ my %seen;
+ $seen{$_}++ for @roles;
+ if (my @dupes = grep $seen{$_} > 1, @roles) {
+ die "Duplicated roles: ".join(', ', @dupes);
+ }
+ }
+
my $new_name = join(
'__WITH__', $superclass, my $compose_name = join '__AND__', @roles
);
require MRO::Compat;
}
+ my %conflicts = %{$me->_composite_info_for(@roles)->{conflicts}};
+ if (keys %conflicts) {
+ my $fail =
+ join "\n",
+ map {
+ "Method name conflict for '$_' between roles "
+ ."'".join(' and ', sort values %{$conflicts{$_}})."'"
+ .", cannot apply these simultaneously to an object."
+ } keys %conflicts;
+ die $fail;
+ }
+
my @composable = map $me->_composable_package_for($_), reverse @roles;
*{_getglob("${new_name}::ISA")} = [ @composable, $superclass ];
return $new_name;
}
-sub apply_union_of_roles_to_package {
+# preserved for compat, and apply_roles_to_package calls it to allow an
+# updated Role::Tiny to use a non-updated Moo::Role
+
+sub apply_role_to_package { shift->apply_single_role_to_package(@_) }
+
+sub apply_roles_to_package {
my ($me, $to, @roles) = @_;
return $me->apply_role_to_package($to, $roles[0]) if @roles == 1;
- _load_module($_) for @roles;
- my %methods;
- foreach my $role (@roles) {
- my $this_methods = $me->_concrete_methods_of($role);
- $methods{$_}{$this_methods->{$_}} = $role for keys %$this_methods;
- }
- delete $methods{$_} for grep keys(%{$methods{$_}}) == 1, keys %methods;
- delete $methods{$_} for $me->_concrete_methods_of($to);
- if (keys %methods) {
+ my %conflicts = %{$me->_composite_info_for(@roles)->{conflicts}};
+ delete $conflicts{$_} for $me->_concrete_methods_of($to);
+ if (keys %conflicts) {
my $fail =
join "\n",
- map "$_ is provided by: ".join(', ', values %{$methods{$_}}),
- keys %methods;
- die "Conflict combining ".join(', ', @roles);
+ map {
+ "Due to a method name conflict between roles "
+ ."'".join(' and ', sort values %{$conflicts{$_}})."'"
+ .", the method '$_' must be implemented by '${to}'"
+ } keys %conflicts;
+ die $fail;
}
+ delete $INFO{$to}{methods}; # reset since we're about to add methods
$me->apply_role_to_package($to, $_) for @roles;
+ $APPLIED_TO{$to}{join('|',@roles)} = 1;
+}
+
+sub _composite_info_for {
+ my ($me, @roles) = @_;
+ $COMPOSITE_INFO{join('|', sort @roles)} ||= do {
+ _load_module($_) for @roles;
+ my %methods;
+ foreach my $role (@roles) {
+ my $this_methods = $me->_concrete_methods_of($role);
+ $methods{$_}{$this_methods->{$_}} = $role for keys %$this_methods;
+ }
+ delete $methods{$_} for grep keys(%{$methods{$_}}) == 1, keys %methods;
+ +{ conflicts => \%methods }
+ };
}
sub _composable_package_for {
my $info = $INFO{$role};
# grab role symbol table
my $stash = do { no strict 'refs'; \%{"${role}::"}};
- my $not_methods = $info->{not_methods};
- +{
+ # reverse so our keys become the values (captured coderefs) in case
+ # they got copied or re-used since
+ my $not_methods = { reverse %{$info->{not_methods}||{}} };
+ $info->{methods} ||= +{
# grab all code entries that aren't in the not_methods list
map {
my $code = *{$stash->{$_}}{CODE};
=back
Unlike L<Class::C3>, where the B<last> class inherited from "wins," role
-composition is the other way around, where first wins. In a more complete
-system (see L<Moose>) roles are checked to see if they clash. The goal of this
-is to be much simpler, hence disallowing composition of multiple roles at once.
-
-=head1 METHODS
-
-=head2 apply_role_to_package
-
- Role::Tiny->apply_role_to_package('Some::Package', 'Some::Role');
-
-Composes role with package. See also L<Role::Tiny::With>.
-
-=head2 apply_roles_to_object
-
- Role::Tiny->apply_roles_to_object($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('Some::Role')) {
- ...
- }
-
-will work for classes but to test a role, one must use ::does_role directly
+composition is the other way around, where the class wins. If multiple roles
+are applied in a single call (single with statement), then if any of their
+provided methods clash, an exception is raised unless the class provides
+a method since this conflict indicates a potential problem.
=head1 IMPORTED SUBROUTINES
=head2 with
with 'Some::Role1';
+
+ with 'Some::Role1', 'Some::Role2';
+
+Composes another role into the current role (or class via L<Role::Tiny::With>).
+
+If you have conflicts and want to resolve them in favour of Some::Role1 you
+can instead write:
+
+ 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.
+If you have conflicts and want to resolve different conflicts in favour of
+different roles, please refactor your codebase.
=head2 before
a dependency. If your L<Role::Tiny> role uses modifiers you must depend on
both L<Class::Method::Modifiers> and L<Role::Tiny>.
+=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('Some::Role')) {
+ ...
+ }
+
+will work for classes but to test a role, one must use ::does_role directly
+
+=head1 METHODS
+
+=head2 apply_roles_to_package
+
+ Role::Tiny->apply_roles_to_package(
+ 'Some::Package', 'Some::Role', 'Some::Other::Role'
+ );
+
+Composes role with package. See also L<Role::Tiny::With>.
+
+=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 SEE ALSO
L<Role::Tiny> is the attribute-less subset of L<Moo::Role>; L<Moo::Role> is
If you don't want method modifiers and do want to be forcibly restricted
to a single role application per class, Ovid's L<Role::Basic> exists. But
-Stevan Little (the L<Moose> author) and I are both still convinced that
-he's Doing It Wrong.
+Stevan Little (the L<Moose> author) and I don't find the additional
+restrictions to be amazingly helpful in most cases; L<Role::Basic>'s choices
+are more a guide to what you should prefer doing, to our mind, rather than
+something that needs to be enforced.
=head1 AUTHOR
perigrin - Chris Prather (cpan:PERIGRIN) <chris@prather.org>
+Mithaldu - Christian Walde (cpan:MITHALDU) <walde.christian@googlemail.com>
+
=head1 COPYRIGHT
Copyright (c) 2010-2012 the Role::Tiny L</AUTHOR> and L</CONTRIBUTORS>
projects / gitmo/Role-Tiny.git / blobdiff