X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FRole%2FTiny.pm;h=04a44d15fbf98ec0ac1c1e5db7e979cb42be02b8;hb=123a5a6e906ff637e8527949e292efb60ea68724;hp=fce2018f603e094bc279b53ad07aa07dafa0299a;hpb=60dfe768e64a52bf2245361c2da546c45567553b;p=gitmo%2FRole-Tiny.git diff --git a/lib/Role/Tiny.pm b/lib/Role/Tiny.pm index fce2018..04a44d1 100644 --- a/lib/Role/Tiny.pm +++ b/lib/Role/Tiny.pm @@ -6,12 +6,13 @@ sub _getstash { \%{"$_[0]::"} } use strict; use warnings FATAL => 'all'; -our $VERSION = '1.000001'; # 1.0.1 +our $VERSION = '1.001002'; # 1.1.2 $VERSION = eval $VERSION; our %INFO; our %APPLIED_TO; our %COMPOSED; +our %COMPOSITE_INFO; # Module state workaround totally stolen from Zefram's Module::Runtime. @@ -50,26 +51,28 @@ sub import { *{_getglob "${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); @@ -105,6 +108,14 @@ sub create_class_with_roles { 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 $compose_name = join '__AND__', @roles ); @@ -122,6 +133,18 @@ sub create_class_with_roles { require MRO::Compat; } + my %conflicts = %{$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 ]; @@ -143,27 +166,45 @@ sub create_class_with_roles { 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 { @@ -209,8 +250,10 @@ sub _concrete_methods_of { 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->{$_}}{CODE}; @@ -332,50 +375,10 @@ role application will fail loudly. =back Unlike L, where the B class inherited from "wins," role -composition is the other way around, where first wins. In a more complete -system (see L) roles are checked to see if they clash. The goal of this -is to be much simpler, hence disallowing composition of multiple roles at once. - -=head1 METHODS - -=head2 apply_role_to_package - - Role::Tiny->apply_role_to_package('Some::Package', 'Some::Role'); - -Composes role with package. See also L. - -=head2 apply_roles_to_object - - Role::Tiny->apply_roles_to_object($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 @@ -388,10 +391,19 @@ Declares a list of methods that must be defined to compose role. =head2 with with 'Some::Role1'; + + with 'Some::Role1', 'Some::Role2'; + +Composes another role into the current role (or class via L). + +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 @@ -429,6 +441,49 @@ L is lazily loaded and we do not declare it as a dependency. If your L role uses modifiers you must depend on both L and L. +=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. + +=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 is the attribute-less subset of L; L is @@ -436,8 +491,10 @@ a meta-protocol-less subset of the king of role systems, L. If you don't want method modifiers and do want to be forcibly restricted to a single role application per class, Ovid's L exists. But -Stevan Little (the L author) and I are both still convinced that -he's Doing It Wrong. +Stevan Little (the L author) and I don't find the additional +restrictions to be amazingly helpful in most cases; L'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 @@ -463,6 +520,8 @@ doy - Jesse Luehrs (cpan:DOY) perigrin - Chris Prather (cpan:PERIGRIN) +Mithaldu - Christian Walde (cpan:MITHALDU) + =head1 COPYRIGHT Copyright (c) 2010-2012 the Role::Tiny L and L