X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FRole%2FTiny.pm;h=6f6a97d4ec88f570c2944b47151419aaee249ac5;hb=3117a19eae72e3b1f2af43456ebf52a880593f9b;hp=447901261b9b6612bbafb9fef8a811f1b25a25ce;hpb=7b8177f835014e871d1c75016272ba320f4cd975;p=gitmo%2FRole-Tiny.git diff --git a/lib/Role/Tiny.pm b/lib/Role/Tiny.pm index 4479012..6f6a97d 100644 --- a/lib/Role/Tiny.pm +++ b/lib/Role/Tiny.pm @@ -6,60 +6,73 @@ sub _getstash { \%{"$_[0]::"} } use strict; use warnings FATAL => 'all'; +our $VERSION = '1.002004'; # 1.2.4 +$VERSION = eval $VERSION; + our %INFO; our %APPLIED_TO; our %COMPOSED; +our %COMPOSITE_INFO; + +# Module state workaround totally stolen from Zefram's Module::Runtime. -# inlined from Moo::_Utils - update that first. +BEGIN { + *_WORK_AROUND_BROKEN_MODULE_STATE = "$]" < 5.009 ? sub(){1} : sub(){0}; +} + +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])||{}}; - { local $@; require "${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; } -{ # \[] is REF, not SCALAR. \v1 is VSTRING (thanks to doy for that one) - my %reftypes = map +($_ => 1), qw(SCALAR REF VSTRING); - sub _is_scalar_ref { $reftypes{ref($_[0])} } -} - 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}::"} }; + my $stash = _getstash($target); # install before/after/around subs foreach my $type (qw(before after around)) { *{_getglob "${target}::${type}"} = sub { - { local $@; require Class::Method::Modifiers; } + require Class::Method::Modifiers; push @{$INFO{$target}{modifiers}||=[]}, [ $type => @_ ]; + return; }; } *{_getglob "${target}::requires"} = sub { push @{$INFO{$target}{requires}||=[]}, @_; + return; }; *{_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, @_); + 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 { *$_{CODE}||() } grep !_is_scalar_ref($_), 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); @@ -73,11 +86,6 @@ sub apply_role_to_package { $me->_install_modifiers($to, $info->{modifiers}); - # only add does() method to classes and only if they don't have one - if (not $INFO{$to} and not $to->can('does')) { - *{_getglob "${to}::does"} = \&does_role; - } - # copy our role list into the target's @{$APPLIED_TO{$to}||={}}{keys %{$APPLIED_TO{$role}}} = (); } @@ -95,6 +103,15 @@ sub create_class_with_roles { die "No roles supplied!" unless @roles; + _load_module($superclass); + { + 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 ); @@ -103,28 +120,38 @@ sub create_class_with_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) { - { local $@; require mro; } + require mro; } else { - { local $@; require MRO::Compat; } + require MRO::Compat; + } + + my %conflicts = %{$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, $superclass ]; - my @info = map +($INFO{$_} ? $INFO{$_} : ()), @roles; + my @info = map $INFO{$_}, @roles; $me->_check_requires( $new_name, $compose_name, do { my %h; @h{map @{$_->{requires}||[]}, @info} = (); keys %h } ); - *{_getglob "${new_name}::does"} = \&does_role unless $new_name->can('does'); - @{$APPLIED_TO{$new_name}||={}}{ map keys %{$APPLIED_TO{$_}}, @roles } = (); @@ -133,13 +160,69 @@ sub create_class_with_roles { return $new_name; } +# preserved for compat, and apply_roles_to_package calls it to allow an +# updated Role::Tiny to use a non-updated Moo::Role + +sub apply_role_to_package { shift->apply_single_role_to_package(@_) } + +sub apply_roles_to_package { + my ($me, $to, @roles) = @_; + + return $me->apply_role_to_package($to, $roles[0]) if @roles == 1; + + my %conflicts = %{$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; + } + + # the if guard here is essential since otherwise we accidentally create + # a $INFO for something that isn't a Role::Tiny (or Moo::Role) because + # autovivification hates us and wants us to die() + if ($INFO{$to}) { + delete $INFO{$to}{methods}; # reset since we're about to add methods + } + + foreach my $role (@roles) { + $me->apply_single_role_to_package($to, $role); + } + $APPLIED_TO{$to}{join('|',@roles)} = 1; +} + +sub _composite_info_for { + my ($me, @roles) = @_; + $COMPOSITE_INFO{join('|', sort @roles)} ||= do { + foreach my $role (@roles) { + _load_module($role); + } + 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; return $composed_name if $COMPOSED{role}{$composed_name}; $me->_install_methods($composed_name, $role); my $base_name = $composed_name.'::_BASE'; - *{_getglob("${composed_name}::ISA")} = [ $base_name ]; + # Not using _getglob, since setting @ISA via the typeglob breaks + # inheritance on 5.10.0 if the stash has previously been accessed an + # then a method called on the class (in that order!), which + # ->_install_methods (with the help of ->_install_does) ends up doing. + { no strict 'refs'; @{"${composed_name}::ISA"} = ( $base_name ); } my $modifiers = $INFO{$role}{modifiers}||[]; my @mod_base; foreach my $modified ( @@ -147,11 +230,13 @@ sub _composable_package_for { ) { push @mod_base, "sub ${modified} { shift->next::method(\@_) }"; } + my $e; { local $@; eval(my $code = join "\n", "package ${base_name};", @mod_base); - die "Evaling failed: $@\nTrying to eval:\n${code}" if $@; + $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 $composed_name; @@ -172,18 +257,18 @@ sub _check_requires { sub _concrete_methods_of { my ($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||''} ? () : ($_ => $code) - } grep !_is_scalar_ref($stash->{$_}), keys %$stash - }; + # grab role symbol table + my $stash = _getstash($role); + # 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}; + # rely on the '' key we added in import for "no code here" + exists $not_methods->{$code||''} ? () : ($_ => $code) + } grep !ref($stash->{$_}), keys %$stash }; } @@ -201,12 +286,12 @@ sub _install_methods { my $methods = $me->_concrete_methods_of($role); # grab target symbol table - my $stash = do { no strict 'refs'; \%{"${to}::"}}; + my $stash = _getstash($to); # determine already extant methods of target my %has_methods; @has_methods{grep - +(_is_scalar_ref($stash->{$_}) || *{$stash->{$_}}{CODE}), + +(ref($stash->{$_}) || *{$stash->{$_}}{CODE}), keys %$stash } = (); @@ -214,6 +299,8 @@ sub _install_methods { no warnings 'once'; *{_getglob "${to}::${i}"} = $methods->{$i}; } + + $me->_install_does($to); } sub _install_modifiers { @@ -227,21 +314,59 @@ sub _install_modifiers { } } +my $vcheck_error; + sub _install_single_modifier { my ($me, @args) = @_; + defined($vcheck_error) or $vcheck_error = do { + local $@; + eval { Class::Method::Modifiers->VERSION(1.05); 1 } + ? 0 + : $@ + }; + $vcheck_error and die $vcheck_error; Class::Method::Modifiers::install_modifier(@args); } +my $FALLBACK = sub { 0 }; +sub _install_does { + my ($me, $to) = @_; + + # only add does() method to classes + return if $INFO{$to}; + + # add does() only if they don't have one + *{_getglob "${to}::does"} = \&does_role unless $to->can('does'); + + return if ($to->can('DOES') and $to->can('DOES') != (UNIVERSAL->can('DOES') || 0)); + + my $existing = $to->can('DOES') || $to->can('isa') || $FALLBACK; + my $new_sub = sub { + my ($proto, $role) = @_; + Role::Tiny::does_role($proto, $role) or $proto->$existing($role); + }; + no warnings 'redefine'; + *{_getglob "${to}::DOES"} = $new_sub; +} + sub does_role { my ($proto, $role) = @_; - return exists $APPLIED_TO{ref($proto)||$proto}{$role}; + if ($] >= 5.010) { + require mro; + } else { + require MRO::Compat; + } + foreach my $class (@{mro::get_linear_isa(ref($proto)||$proto)}) { + return 1 if exists $APPLIED_TO{$class}{$role}; + } + return 0; } 1; =head1 NAME -Role::Tiny - Roles. Like a nouvelle cusine portion size slice of Moose. +Role::Tiny - Roles. Like a nouvelle cuisine portion size slice of Moose. =head1 SYNOPSIS @@ -253,6 +378,8 @@ Role::Tiny - Roles. Like a nouvelle cusine portion size slice of Moose. sub bar { ... } + around baz => sub { ... } + 1; else where @@ -266,8 +393,13 @@ else where sub foo { ... } + # baz is wrapped in the around modifier by Class::Method::Modifiers + sub baz { ... } + 1; +If you wanted attributes as well, look at L. + =head1 DESCRIPTION C is a minimalist role composition tool. @@ -292,31 +424,71 @@ role application will fail loudly. =back Unlike L, where the B class inherited from "wins," role -composition is the other way around, where first wins. In a more complete -system (see L) roles are checked to see if they clash. The goal of this -is to be much simpler, hence disallowing composition of multiple roles at once. +composition is the other way around, where the class wins. If multiple roles +are applied in a single call (single with statement), then if any of their +provided methods clash, an exception is raised unless the class provides +a method since this conflict indicates a potential problem. -=head1 METHODS +=head1 IMPORTED SUBROUTINES -=head2 apply_role_to_package +=head2 requires - Role::Tiny->apply_role_to_package('Some::Package', 'Some::Role'); + requires qw(foo bar); -Composes role with package. See also L. +Declares a list of methods that must be defined to compose role. -=head2 apply_roles_to_object +=head2 with - Role::Tiny->apply_roles_to_object($foo, qw(Some::Role1 Some::Role2)); + with 'Some::Role1'; -Composes roles in order into object directly. Object is reblessed into the -resulting class. + with 'Some::Role1', 'Some::Role2'; -=head2 create_class_with_roles +Composes another role into the current role (or class via L). - Role::Tiny->create_class_with_roles('Some::Base', qw(Some::Role1 Some::Role2)); +If you have conflicts and want to resolve them in favour of Some::Role1 you +can instead write: -Creates a new class based on base, with the roles composed into it in order. -New class is returned. + with 'Some::Role1'; + with 'Some::Role2'; + +If you have conflicts and want to resolve different conflicts in favour of +different roles, please refactor your codebase. + +=head2 before + + before foo => sub { ... }; + +See L<< Class::Method::Modifiers/before method(s) => sub { ... } >> for full +documentation. + +Note that since you are not required to use method modifiers, +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. + +=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 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. + +=head2 after + + after foo => sub { ... }; + +See L<< Class::Method::Modifiers/after method(s) => sub { ... } >> for full +documentation. + +Note that since you are not required to use method modifiers, +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 @@ -331,55 +503,90 @@ 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 ($foo->does_role('Some::Role')) { + if ($foo->does('Some::Role')) { ... } -will work for classes but to test a role, one must use ::does_role directly +will work for classes but to test a role, one must use ::does_role directly. -=head1 IMPORTED SUBROUTINES +Additionally, Role::Tiny will override the standard Perl C method +for your class. However, if C class in your class' inheritance +heirarchy provides C, then Role::Tiny will not override it. -=head2 requires +=head1 METHODS - requires qw(foo bar); +=head2 apply_roles_to_package -Declares a list of methods that must be defined to compose role. + Role::Tiny->apply_roles_to_package( + 'Some::Package', 'Some::Role', 'Some::Other::Role' + ); -=head2 with +Composes role with package. See also L. - with 'Some::Role1'; - with 'Some::Role2'; +=head2 apply_roles_to_object -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. + Role::Tiny->apply_roles_to_object($foo, qw(Some::Role1 Some::Role2)); -=head2 before +Composes roles in order into object directly. Object is reblessed into the +resulting class. - before foo => sub { ... }; +=head2 create_class_with_roles -See L<< Class::Method::Modifiers/before method(s) => sub { ... } >> for full -documentation. + Role::Tiny->create_class_with_roles('Some::Base', qw(Some::Role1 Some::Role2)); -=head2 around +Creates a new class based on base, with the roles composed into it in order. +New class is returned. - around foo => sub { ... }; +=head1 SEE ALSO -See L<< Class::Method::Modifiers/around method(s) => sub { ... } >> for full -documentation. +L is the attribute-less subset of L; L is +a meta-protocol-less subset of the king of role systems, L. -=head2 after +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 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. - after foo => sub { ... }; +=head1 AUTHOR -See L<< Class::Method::Modifiers/after method(s) => sub { ... } >> for full -documentation. +mst - Matt S. Trout (cpan:MSTROUT) + +=head1 CONTRIBUTORS + +dg - David Leadbeater (cpan:DGL) + +frew - Arthur Axel "fREW" Schmidt (cpan:FREW) + +hobbs - Andrew Rodland (cpan:ARODLAND) + +jnap - John Napiorkowski (cpan:JJNAPIORK) + +ribasushi - Peter Rabbitson (cpan:RIBASUSHI) + +chip - Chip Salzenberg (cpan:CHIPS) + +ajgb - Alex J. G. Burzyński (cpan:AJGB) + +doy - Jesse Luehrs (cpan:DOY) + +perigrin - Chris Prather (cpan:PERIGRIN) + +Mithaldu - Christian Walde (cpan:MITHALDU) + +ilmari - Dagfinn Ilmari Mannsåker (cpan:ILMARI) + +tobyink - Toby Inkster (cpan:TOBYINK) -=head1 AUTHORS +=head1 COPYRIGHT -See L for authors. +Copyright (c) 2010-2012 the Role::Tiny L and L +as listed above. -=head1 COPYRIGHT AND LICENSE +=head1 LICENSE -See L for the copyright and license. +This library is free software and may be distributed under the same terms +as perl itself. =cut