X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FRole%2FTiny.pm;h=b034790f635ba0ef8a675445249ac336ccd94f0d;hb=ed1d913d2c76d5a412083fe6e4a3cd3d313f9aed;hp=de6a09ecdcc5c7ee45b720e467608e1a2c724250;hpb=b6d9324bf5cf073c46caf27252eeea6a3841aecf;p=gitmo%2FRole-Tiny.git diff --git a/lib/Role/Tiny.pm b/lib/Role/Tiny.pm index de6a09e..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 = '1.002005'; # 1.2.5 +our $VERSION = '1.003002'; $VERSION = eval $VERSION; our %INFO; @@ -43,7 +43,8 @@ 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 $stash = _getstash($target); # install before/after/around subs @@ -64,28 +65,33 @@ sub import { }; # 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) with a map to the coderefs in case of copying or re-use - my @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, $role); + die "${role} is not a Role::Tiny" unless $me->is_role($role); - $me->_install_modifiers($to, $info->{modifiers}); + 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{$role}}} = (); } @@ -94,8 +100,24 @@ sub apply_roles_to_object { my ($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 { @@ -112,15 +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 ($] >= 5.010) { @@ -129,7 +149,8 @@ sub create_class_with_roles { require MRO::Compat; } - my %conflicts = %{$me->_composite_info_for(@roles)->{conflicts}}; + my $composite_info = $me->_composite_info_for(@roles); + my %conflicts = %{$composite_info->{conflicts}}; if (keys %conflicts) { my $fail = join "\n", @@ -143,15 +164,22 @@ sub create_class_with_roles { my @composable = map $me->_composable_package_for($_), reverse @roles; - *{_getglob("${new_name}::ISA")} = [ @composable, $superclass ]; - - 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}::ISA")} = [ @composable, $superclass ]; + @{$APPLIED_TO{$new_name}||={}}{ map keys %{$APPLIED_TO{$_}}, @roles } = (); @@ -171,7 +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", @@ -183,6 +213,15 @@ sub apply_roles_to_package { die $fail; } + # 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() @@ -190,8 +229,27 @@ sub apply_roles_to_package { delete $INFO{$to}{methods}; # reset since we're about to add methods } - foreach my $role (@roles) { - $me->apply_single_role_to_package($to, $role); + # backcompat: allow subclasses to use apply_single_role_to_package + # to apply changes. set a local var so ours does nothing. + our %BACKCOMPAT_HACK; + if($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; } @@ -207,8 +265,11 @@ sub _composite_info_for { 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] } }; } @@ -218,6 +279,8 @@ sub _composable_package_for { return $composed_name if $COMPOSED{role}{$composed_name}; $me->_install_methods($composed_name, $role); my $base_name = $composed_name.'::_BASE'; + # force stash to exist so ->can doesn't complain + _getstash($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 @@ -225,9 +288,9 @@ sub _composable_package_for { { 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; @@ -237,13 +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}) { @@ -266,16 +332,15 @@ sub _concrete_methods_of { # 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 { @@ -297,14 +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 { @@ -331,15 +411,16 @@ sub _install_single_modifier { my $FALLBACK = sub { 0 }; sub _install_does { my ($me, $to) = @_; - + # only add does() method to classes - return if $INFO{$to}; - + 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)); - + + 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, $role) = @_; @@ -362,8 +443,15 @@ sub does_role { return 0; } +sub is_role { + my ($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. @@ -490,6 +578,15 @@ 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 @@ -511,7 +608,7 @@ 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 -heirarchy provides C, then Role::Tiny will not override it. +hierarchy provides C, then Role::Tiny will not override it. =head1 METHODS @@ -537,17 +634,26 @@ resulting class. 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) 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. +Ovid's L provides roles with a similar scope, but without method +modifiers, and having some extra usage restrictions. =head1 AUTHOR @@ -579,6 +685,8 @@ 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