X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FRole%2FTiny.pm;h=b034790f635ba0ef8a675445249ac336ccd94f0d;hb=ed1d913d2c76d5a412083fe6e4a3cd3d313f9aed;hp=0a3865036850bd44a34325f80cc3c19b04e1773f;hpb=d55a3fb583df0fe8e860630840c753bfd635abd7;p=gitmo%2FRole-Tiny.git diff --git a/lib/Role/Tiny.pm b/lib/Role/Tiny.pm index 0a38650..b034790 100644 --- a/lib/Role/Tiny.pm +++ b/lib/Role/Tiny.pm @@ -6,7 +6,7 @@ sub _getstash { \%{"$_[0]::"} } use strict; use warnings FATAL => 'all'; -our $VERSION = '1.000_901'; # 1.0.901 +our $VERSION = '1.003002'; $VERSION = eval $VERSION; our %INFO; @@ -43,52 +43,55 @@ sub import { my $me = shift; strict->import; warnings->import(FATAL => 'all'); - return if $INFO{$target}; # already exported into this package + return if $me->is_role($target); # already exported into this package + $INFO{$target}{is_role} = 1; # 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}::${type}"} = sub { require Class::Method::Modifiers; push @{$INFO{$target}{modifiers}||=[]}, [ $type => @_ ]; + return; }; } *{_getglob "${target}::requires"} = sub { push @{$INFO{$target}{requires}||=[]}, @_; + return; }; *{_getglob "${target}::with"} = sub { $me->apply_roles_to_package($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 %$stash - } = (); + # inflate constant subs into real subs) with a map to the coderefs in + # case of copying or re-use + my @not_methods = (map { *$_{CODE}||() } grep !ref($_), values %$stash); + @{$INFO{$target}{not_methods}={}}{@not_methods} = @not_methods; # a role does itself $APPLIED_TO{$target} = { $target => undef }; } +sub role_application_steps { + qw(_install_methods _check_requires _install_modifiers _copy_applied_list); +} + sub apply_single_role_to_package { my ($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}; - - $me->_check_requires($to, $role, @{$info->{requires}||[]}); - - $me->_install_methods($to, $role); - - $me->_install_modifiers($to, $info->{modifiers}); + die "${role} is not a Role::Tiny" unless $me->is_role($role); - # 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; + foreach my $step ($me->role_application_steps) { + $me->$step($to, $role); } +} +sub _copy_applied_list { + my ($me, $to, $role) = @_; # copy our role list into the target's @{$APPLIED_TO{$to}||={}}{keys %{$APPLIED_TO{$role}}} = (); } @@ -97,8 +100,24 @@ sub apply_roles_to_object { my ($me, $object, @roles) = @_; die "No roles supplied!" unless @roles; my $class = ref($object); - bless($object, $me->create_class_with_roles($class, @roles)); - $object; + # on perl < 5.8.9, magic isn't copied to all ref copies. bless the parameter + # directly, so at least the variable passed to us will get any magic applied + bless($_[1], $me->create_class_with_roles($class, @roles)); +} + +my $role_suffix = 'A000'; +sub _composite_name { + my ($me, $superclass, @roles) = @_; + + my $new_name = join( + '__WITH__', $superclass, my $compose_name = join '__AND__', @roles + ); + + if (length($new_name) > 252) { + $new_name = $COMPOSED{abbrev}{$new_name} + ||= substr($new_name, 0, 250 - length $role_suffix).'__'.$role_suffix++; + } + return wantarray ? ($new_name, $compose_name) : $new_name; } sub create_class_with_roles { @@ -106,6 +125,7 @@ sub create_class_with_roles { die "No roles supplied!" unless @roles; + _load_module($superclass); { my %seen; $seen{$_}++ for @roles; @@ -114,15 +134,13 @@ sub create_class_with_roles { } } - my $new_name = join( - '__WITH__', $superclass, my $compose_name = join '__AND__', @roles - ); + my ($new_name, $compose_name) = $me->_composite_name($superclass, @roles); return $new_name if $COMPOSED{class}{$new_name}; foreach my $role (@roles) { _load_module($role); - die "${role} is not a Role::Tiny" unless $INFO{$role}; + die "${role} is not a Role::Tiny" unless $me->is_role($role); } if ($] >= 5.010) { @@ -131,18 +149,36 @@ sub create_class_with_roles { require MRO::Compat; } - my @composable = map $me->_composable_package_for($_), reverse @roles; + my $composite_info = $me->_composite_info_for(@roles); + my %conflicts = %{$composite_info->{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 $fail; + } - *{_getglob("${new_name}::ISA")} = [ @composable, $superclass ]; + my @composable = map $me->_composable_package_for($_), reverse @roles; - my @info = map $INFO{$_}, @roles; + # some methods may not exist in the role, but get generated by + # _composable_package_for (Moose accessors via Moo). filter out anything + # provided by the composable packages, excluding the subs we generated to + # make modifiers work. + my @requires = grep { + my $method = $_; + !grep $_->can($method) && !$COMPOSED{role}{$_}{modifiers_only}{$method}, + @composable + } @{$composite_info->{requires}}; $me->_check_requires( - $new_name, $compose_name, - do { my %h; @h{map @{$_->{requires}||[]}, @info} = (); keys %h } + $superclass, $compose_name, \@requires ); - *{_getglob "${new_name}::does"} = \&does_role unless $new_name->can('does'); + *{_getglob("${new_name}::ISA")} = [ @composable, $superclass ]; @{$APPLIED_TO{$new_name}||={}}{ map keys %{$APPLIED_TO{$_}}, @roles @@ -163,7 +199,9 @@ sub apply_roles_to_package { 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); + my @have = grep $to->can($_), keys %conflicts; + delete @conflicts{@have}; + if (keys %conflicts) { my $fail = join "\n", @@ -174,22 +212,64 @@ sub apply_roles_to_package { } keys %conflicts; die $fail; } - delete $INFO{$to}{methods}; # reset since we're about to add methods - $me->apply_role_to_package($to, $_) for @roles; + + # conflicting methods are supposed to be treated as required by the + # composed role. we don't have an actual composed role, but because + # we know the target class already provides them, we can instead + # pretend that the roles don't do for the duration of application. + my @role_methods = map $me->_concrete_methods_of($_), @roles; + # separate loops, since local ..., delete ... for ...; creates a scope + local @{$_}{@have} for @role_methods; + delete @{$_}{@have} for @role_methods; + + # 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 + } + + # backcompat: allow subclasses to use apply_single_role_to_package + # to apply changes. set a local var so ours does nothing. + our %BACKCOMPAT_HACK; + if($me ne __PACKAGE__ + and exists $BACKCOMPAT_HACK{$me} ? $BACKCOMPAT_HACK{$me} : + $BACKCOMPAT_HACK{$me} = + $me->can('role_application_steps') + == \&role_application_steps + && $me->can('apply_single_role_to_package') + != \&apply_single_role_to_package + ) { + foreach my $role (@roles) { + $me->apply_single_role_to_package($to, $role); + } + } + else { + foreach my $step ($me->role_application_steps) { + foreach my $role (@roles) { + $me->$step($to, $role); + } + } + } $APPLIED_TO{$to}{join('|',@roles)} = 1; } sub _composite_info_for { my ($me, @roles) = @_; $COMPOSITE_INFO{join('|', sort @roles)} ||= do { - _load_module($_) for @roles; + 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; } + my %requires; + @requires{map @{$INFO{$_}{requires}||[]}, @roles} = (); + delete $requires{$_} for keys %methods; delete $methods{$_} for grep keys(%{$methods{$_}}) == 1, keys %methods; - +{ conflicts => \%methods } + +{ conflicts => \%methods, requires => [keys %requires] } }; } @@ -199,12 +279,18 @@ sub _composable_package_for { return $composed_name if $COMPOSED{role}{$composed_name}; $me->_install_methods($composed_name, $role); my $base_name = $composed_name.'::_BASE'; - *{_getglob("${composed_name}::ISA")} = [ $base_name ]; + # force stash to exist so ->can doesn't complain + _getstash($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 ( - do { my %h; @h{map $_->[1], @$modifiers} = (); keys %h } - ) { + my @modifiers = grep !$composed_name->can($_), + do { my %h; @h{map @{$_}[1..$#$_-1], @$modifiers} = (); keys %h }; + foreach my $modified (@modifiers) { push @mod_base, "sub ${modified} { shift->next::method(\@_) }"; } my $e; @@ -214,13 +300,16 @@ sub _composable_package_for { $e = "Evaling failed: $@\nTrying to eval:\n${code}" if $@; } die $e if $e; - $me->_install_modifiers($composed_name, $modifiers); - $COMPOSED{role}{$composed_name} = 1; + $me->_install_modifiers($composed_name, $role); + $COMPOSED{role}{$composed_name} = { + modifiers_only => { map { $_ => 1 } @modifiers }, + }; return $composed_name; } sub _check_requires { - my ($me, $to, $name, @requires) = @_; + my ($me, $to, $name, $requires) = @_; + return unless my @requires = @{$requires||$INFO{$name}{requires}||[]}; if (my @requires_fail = grep !$to->can($_), @requires) { # role -> role, add to requires, role -> class, error out if (my $to_info = $INFO{$to}) { @@ -235,22 +324,23 @@ sub _concrete_methods_of { my ($me, $role) = @_; my $info = $INFO{$role}; # grab role symbol table - my $stash = do { no strict 'refs'; \%{"${role}::"}}; - my $not_methods = $info->{not_methods}; + 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) + ( ! $code or exists $not_methods->{$code} ) ? () : ($_ => $code) } grep !ref($stash->{$_}), keys %$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)}, @{$info->{requires}||[]}); + die "${role} is not a Role::Tiny" unless $me->is_role($role); + (keys %{$me->_concrete_methods_of($role)}, @{$INFO{$role}->{requires}||[]}); } sub _install_methods { @@ -261,7 +351,7 @@ 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; @@ -272,12 +362,29 @@ sub _install_methods { foreach my $i (grep !exists $has_methods{$_}, keys %$methods) { no warnings 'once'; - *{_getglob "${to}::${i}"} = $methods->{$i}; + my $glob = _getglob "${to}::${i}"; + *$glob = $methods->{$i}; + + # overloads using method names have the method stored in the scalar slot + # and &overload::nil in the code slot. + next + unless $i =~ /^\(/ + && defined &overload::nil + && $methods->{$i} == \&overload::nil; + + my $overload = ${ *{_getglob "${role}::${i}"}{SCALAR} }; + next + unless defined $overload; + + *$glob = \$overload; } + + $me->_install_does($to); } sub _install_modifiers { - my ($me, $to, $modifiers) = @_; + my ($me, $to, $name) = @_; + return unless my $modifiers = $INFO{$name}{modifiers}; if (my $info = $INFO{$to}) { push @{$info->{modifiers}}, @{$modifiers||[]}; } else { @@ -287,18 +394,64 @@ 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 $me->is_role($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}{$role}; + } + return 0; +} + +sub is_role { + my ($me, $role) = @_; + return !!($INFO{$role} && $INFO{$role}{is_role}); } 1; +=encoding utf-8 + =head1 NAME Role::Tiny - Roles. Like a nouvelle cuisine portion size slice of Moose. @@ -364,49 +517,6 @@ 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_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($foo, qw(Some::Role1 Some::Role2)); - -Composes roles in order into object directly. Object is reblessed into the -resulting class. - -=head2 create_class_with_roles - - Role::Tiny->create_class_with_roles('Some::Base', qw(Some::Role1 Some::Role2)); - -Creates a new class based on base, with the roles composed into it in order. -New class is returned. - -=head1 SUBROUTINES - -=head2 does_role - - if (Role::Tiny::does_role($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 ($foo->does('Some::Role')) { - ... - } - -will work for classes but to test a role, one must use ::does_role directly - =head1 IMPORTED SUBROUTINES =head2 requires @@ -468,17 +578,82 @@ L is lazily loaded and we do not declare it as a dependency. If your L role uses modifiers you must depend on both L and L. +=head2 Strict and Warnings + +In addition to importing subroutines, using C applies L and +L to the caller. It's possible to +disable these if desired: + + use Role::Tiny; + use warnings NONFATAL => 'all'; + +=head1 SUBROUTINES + +=head2 does_role + + if (Role::Tiny::does_role($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 ($foo->does('Some::Role')) { + ... + } + +will work for classes but to test a role, one must use ::does_role directly. + +Additionally, Role::Tiny will override the standard Perl C method +for your class. However, if C class in your class' inheritance +hierarchy provides C, then Role::Tiny will not override it. + +=head1 METHODS + +=head2 apply_roles_to_package + + Role::Tiny->apply_roles_to_package( + 'Some::Package', 'Some::Role', 'Some::Other::Role' + ); + +Composes role with package. See also L. + +=head2 apply_roles_to_object + + Role::Tiny->apply_roles_to_object($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. + +=head2 is_role + + Role::Tiny->is_role('Some::Role1') + +Returns true if the given package is a role. + +=head1 CAVEATS + +=over 4 + +=item * On perl 5.8.8 and earlier, applying a role to an object won't apply any +overloads from the role to all copies of the object. + =head1 SEE ALSO L is the attribute-less subset of L; L is 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) 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. +Ovid's L provides roles with a similar scope, but without method +modifiers, and having some extra usage restrictions. =head1 AUTHOR @@ -504,6 +679,14 @@ 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) + +haarg - Graham Knop (cpan:HAARG) + =head1 COPYRIGHT Copyright (c) 2010-2012 the Role::Tiny L and L