use strict;
use warnings FATAL => 'all';
+our $VERSION = '1.000_900'; # 1.0.900
+$VERSION = eval $VERSION;
+
our %INFO;
our %APPLIED_TO;
our %COMPOSED;
+our %COMPOSITE_INFO;
+
+# Module state workaround totally stolen from Zefram's Module::Runtime.
+
+BEGIN {
+ *_WORK_AROUND_BROKEN_MODULE_STATE = "$]" < 5.009 ? sub(){1} : sub(){0};
+}
-# inlined from Moo::_Utils - update that first.
+sub Role::Tiny::__GUARD__::DESTROY {
+ delete $INC{$_[0]->[0]} if @{$_[0]};
+}
sub _load_module {
(my $proto = $_[0]) =~ s/::/\//g;
- return 1 if $INC{"${proto}.pm"};
+ $proto .= '.pm';
+ return 1 if $INC{$proto};
# can't just ->can('can') because a sub-package Foo::Bar::Baz
# creates a 'Baz::' key in Foo::Bar's symbol table
return 1 if grep !/::$/, keys %{_getstash($_[0])||{}};
- require "${proto}.pm";
+ my $guard = _WORK_AROUND_BROKEN_MODULE_STATE
+ && bless([ $proto ], 'Role::Tiny::__GUARD__');
+ require $proto;
+ pop @$guard if _WORK_AROUND_BROKEN_MODULE_STATE;
return 1;
}
sub import {
my $target = caller;
my $me = shift;
- strictures->import;
+ strict->import;
+ warnings->import(FATAL => 'all');
return if $INFO{$target}; # already exported into this package
# get symbol table reference
my $stash = do { no strict 'refs'; \%{"${target}::"} };
push @{$INFO{$target}{requires}||=[]}, @_;
};
*{_getglob "${target}::with"} = sub {
- die "Only one role supported at a time by with" if @_ > 1;
- $me->apply_role_to_package($target, $_[0]);
+ $me->apply_roles_to_package($target, @_);
};
- # grab all *non-constant* (ref eq 'SCALAR') subs present
+ # 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 { *$_{CODE}||() } grep !(ref eq 'SCALAR'), values %$stash
+ '', map { *$_{CODE}||() } grep !ref($_), values %$stash
} = ();
# 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
);
foreach my $role (@roles) {
_load_module($role);
- die "${role} is not a Role::Tiny" unless my $info = $INFO{$role};
+ die "${role} is not a Role::Tiny" unless $INFO{$role};
}
if ($] >= 5.010) {
*{_getglob("${new_name}::ISA")} = [ @composable, $superclass ];
- my @info = map +($INFO{$_} ? $INFO{$_} : ()), @roles;
+ my @info = map $INFO{$_}, @roles;
$me->_check_requires(
$new_name, $compose_name,
return $new_name;
}
+sub apply_role_to_package { shift->apply_single_role_to_package(@_) }
+
+sub apply_roles_to_package {
+ my ($me, $to, @roles) = @_;
+
+ return $me->apply_single_role_to_package($to, $roles[0]) if @roles == 1;
+
+ my %conflicts = %{$me->_composite_info_for(@roles)->{conflicts}};
+ delete $conflicts{$_} for $me->_concrete_methods_of($to);
+ if (keys %conflicts) {
+ my $fail =
+ join "\n",
+ map {
+ "Due to a method name conflict between roles "
+ ."'".join(' and ', sort values %{$conflicts{$_}})."'"
+ .", the method '$_' must be implemented by '${to}'"
+ } keys %conflicts;
+ die $fail;
+ }
+ $me->apply_single_role_to_package($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 ($me, $role) = @_;
my $composed_name = 'Role::Tiny::_COMPOSABLE::'.$role;
) {
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 $@;
+ my $e;
+ {
+ local $@;
+ eval(my $code = join "\n", "package ${base_name};", @mod_base);
+ $e = "Evaling failed: $@\nTrying to eval:\n${code}" if $@;
+ }
+ die $e if $e;
$me->_install_modifiers($composed_name, $modifiers);
$COMPOSED{role}{$composed_name} = 1;
return $composed_name;
sub _concrete_methods_of {
my ($me, $role) = @_;
my $info = $INFO{$role};
- $info->{methods} ||= do {
- # grab role symbol table
- my $stash = do { no strict 'refs'; \%{"${role}::"}};
- my $not_methods = $info->{not_methods};
- +{
- # grab all code entries that aren't in the not_methods list
- map {
- my $code = *{$stash->{$_}}{CODE};
- # rely on the '' key we added in import for "no code here"
- exists $not_methods->{$code||''} ? () : ($_ => $code)
- } grep !(ref($stash->{$_}) eq 'SCALAR'), keys %$stash
- };
+ # grab role symbol table
+ my $stash = do { no strict 'refs'; \%{"${role}::"}};
+ my $not_methods = $info->{not_methods};
+ +{
+ # grab all code entries that aren't in the not_methods list
+ map {
+ my $code = *{$stash->{$_}}{CODE};
+ # rely on the '' key we added in import for "no code here"
+ exists $not_methods->{$code||''} ? () : ($_ => $code)
+ } grep !ref($stash->{$_}), keys %$stash
};
}
# determine already extant methods of target
my %has_methods;
@has_methods{grep
- +((ref($stash->{$_}) eq 'SCALAR') || (*{$stash->{$_}}{CODE})),
+ +(ref($stash->{$_}) || *{$stash->{$_}}{CODE}),
keys %$stash
} = ();
}
1;
-__END__
=head1 NAME
-Role::Tiny - Roles. Like a nouvelle cusine portion size slice of Moose.
+Role::Tiny - Roles. Like a nouvelle cuisine portion size slice of Moose.
=head1 SYNOPSIS
sub bar { ... }
+ around baz => sub { ... }
+
1;
else where
sub foo { ... }
+ # baz is wrapped in the around modifier by Class::Method::Modifiers
+ sub baz { ... }
+
1;
+If you wanted attributes as well, look at L<Moo::Role>.
+
=head1 DESCRIPTION
C<Role::Tiny> is a minimalist role composition tool.
=back
Unlike L<Class::C3>, where the B<last> class inherited from "wins," role
-composition is the other way around, where first wins. In a more complete
-system (see L<Moose>) roles are checked to see if they clash. The goal of this
-is to be much simpler, hence disallowing composition of multiple roles at once.
+composition is the other way around, where the class wins. If multiple roles
+are applied in a single call (single with statement), then if any of their
+provided methods clash, an exception is raised unless the class provides
+a method since this conflict indicates a potential problem.
=head1 METHODS
-=head2 apply_role_to_package
+=head2 apply_roles_to_package
- Role::Tiny->apply_role_to_package('Some::Package', 'Some::Role');
+ Role::Tiny->apply_roles_to_package(
+ 'Some::Package', 'Some::Role', 'Some::Other::Role'
+ );
Composes role with package. See also L<Role::Tiny::With>.
This subroutine is also installed as ->does on any class a Role::Tiny is
composed into unless that class already has an ->does method, so
- if ($foo->does_role('Some::Role')) {
+ if ($foo->does('Some::Role')) {
...
}
=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
See L<< Class::Method::Modifiers/before method(s) => sub { ... } >> for full
documentation.
+Note that since you are not required to use method modifiers,
+L<Class::Method::Modifiers> is lazily loaded and we do not declare it as
+a dependency. If your L<Role::Tiny> role uses modifiers you must depend on
+both L<Class::Method::Modifiers> and L<Role::Tiny>.
+
=head2 around
around foo => sub { ... };
See L<< Class::Method::Modifiers/around method(s) => sub { ... } >> for full
documentation.
+Note that since you are not required to use method modifiers,
+L<Class::Method::Modifiers> is lazily loaded and we do not declare it as
+a dependency. If your L<Role::Tiny> role uses modifiers you must depend on
+both L<Class::Method::Modifiers> and L<Role::Tiny>.
+
=head2 after
after foo => sub { ... };
See L<< Class::Method::Modifiers/after method(s) => sub { ... } >> for full
documentation.
-=head1 AUTHORS
+Note that since you are not required to use method modifiers,
+L<Class::Method::Modifiers> is lazily loaded and we do not declare it as
+a dependency. If your L<Role::Tiny> role uses modifiers you must depend on
+both L<Class::Method::Modifiers> and L<Role::Tiny>.
+
+=head1 SEE ALSO
+
+L<Role::Tiny> is the attribute-less subset of L<Moo::Role>; L<Moo::Role> is
+a meta-protocol-less subset of the king of role systems, L<Moose::Role>.
+
+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) 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
+
+mst - Matt S. Trout (cpan:MSTROUT) <mst@shadowcat.co.uk>
+
+=head1 CONTRIBUTORS
+
+dg - David Leadbeater (cpan:DGL) <dgl@dgl.cx>
+
+frew - Arthur Axel "fREW" Schmidt (cpan:FREW) <frioux@gmail.com>
+
+hobbs - Andrew Rodland (cpan:ARODLAND) <arodland@cpan.org>
+
+jnap - John Napiorkowski (cpan:JJNAPIORK) <jjn1056@yahoo.com>
+
+ribasushi - Peter Rabbitson (cpan:RIBASUSHI) <ribasushi@cpan.org>
+
+chip - Chip Salzenberg (cpan:CHIPS) <chip@pobox.com>
+
+ajgb - Alex J. G. Burzyński (cpan:AJGB) <ajgb@cpan.org>
+
+doy - Jesse Luehrs (cpan:DOY) <doy at tozt dot net>
+
+perigrin - Chris Prather (cpan:PERIGRIN) <chris@prather.org>
+
+=head1 COPYRIGHT
-See L<Moo> for authors.
+Copyright (c) 2010-2012 the Role::Tiny L</AUTHOR> and L</CONTRIBUTORS>
+as listed above.
-=head1 COPYRIGHT AND LICENSE
+=head1 LICENSE
-See L<Moo> for the copyright and license.
+This library is free software and may be distributed under the same terms
+as perl itself.
=cut
projects / gitmo/Role-Tiny.git / blobdiff