X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FRole%2FTiny.pm;h=eb4cb0b9bf6da723b6f2c4d11c48ad9a5b55d978;hb=adcb6c3d137e9bf582fb3b1818de995c5146e3c3;hp=27f0213519cd6998f6377f77128cb3e3698b67b4;hpb=1947330aa6283819f0e7606fae1dfe732afdae6a;p=gitmo%2FRole-Tiny.git diff --git a/lib/Role/Tiny.pm b/lib/Role/Tiny.pm index 27f0213..eb4cb0b 100644 --- a/lib/Role/Tiny.pm +++ b/lib/Role/Tiny.pm @@ -1,20 +1,54 @@ package Role::Tiny; -use strictures 1; -use Class::Tiny::_Utils; +sub _getglob { \*{$_[0]} } +sub _getstash { \%{"$_[0]::"} } + +use strict; +use warnings FATAL => 'all'; + +our $VERSION = '1.000000'; # 1.0.0 +$VERSION = eval $VERSION; our %INFO; our %APPLIED_TO; our %COMPOSED; +# Module state workaround totally stolen from Zefram's Module::Runtime. + +BEGIN { + *_WORK_AROUND_BROKEN_MODULE_STATE = "$]" < 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; + $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])||{}}; + 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; - strictures->import; + my $me = shift; + 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}::"} }; # install before/after/around subs foreach my $type (qw(before after around)) { *{_getglob "${target}::${type}"} = sub { + require Class::Method::Modifiers; push @{$INFO{$target}{modifiers}||=[]}, [ $type => @_ ]; }; } @@ -23,29 +57,23 @@ sub import { }; *{_getglob "${target}::with"} = sub { die "Only one role supported at a time by with" if @_ > 1; - Role::Tiny->apply_role_to_package($_[0], $target); - }; - *{_getglob "${target}::has"} = sub { - my ($name, %spec) = @_; - ($INFO{$target}{accessor_maker} ||= do { - require Method::Generate::Accessor; - Method::Generate::Accessor->new - })->generate_method($target, $name, \%spec); - $INFO{$target}{attributes}{$name} = \%spec; + $me->apply_role_to_package($target, $_[0]); }; - # grab all *non-constant* (ref eq 'SCALAR') subs present + # grab all *non-constant* (stash slot is not a scalarref) subs present # in the symbol table and store their refaddrs (no need to forcibly # inflate constant subs into real subs) - also add '' to here (this # is used later) @{$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} = { $target => undef }; } sub apply_role_to_package { - my ($me, $role, $to) = @_; + my ($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}; @@ -61,8 +89,6 @@ sub apply_role_to_package { *{_getglob "${to}::does"} = \&does_role; } - $me->_handle_constructor($to, $info->{attributes}); - # copy our role list into the target's @{$APPLIED_TO{$to}||={}}{keys %{$APPLIED_TO{$role}}} = (); } @@ -78,34 +104,35 @@ sub apply_roles_to_object { sub create_class_with_roles { my ($me, $superclass, @roles) = @_; - my $new_name = join('+', $superclass, my $compose_name = join '+', @roles); + die "No roles supplied!" unless @roles; + + my $new_name = join( + '__WITH__', $superclass, my $compose_name = join '__AND__', @roles + ); + return $new_name if $COMPOSED{class}{$new_name}; foreach my $role (@roles) { - die "${role} is not a Role::Tiny" unless my $info = $INFO{$role}; + _load_module($role); + die "${role} is not a Role::Tiny" unless $INFO{$role}; } - if ($] > 5.010) { + if ($] >= 5.010) { require mro; } else { require MRO::Compat; } - require Sub::Quote; - 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 } ); - $me->_handle_constructor( - $new_name, { map %{$_->{attr_info}||{}}, @info } - ); *{_getglob "${new_name}::does"} = \&does_role unless $new_name->can('does'); @@ -125,13 +152,19 @@ sub _composable_package_for { my $base_name = $composed_name.'::_BASE'; *{_getglob("${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 } ) { - Sub::Quote::quote_sub( - "${base_name}::${modified}" => q{ shift->next::method(@_) } - ); + push @mod_base, "sub ${modified} { shift->next::method(\@_) }"; + } + 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 $composed_name; @@ -149,12 +182,10 @@ sub _check_requires { } } -sub _install_methods { - my ($me, $to, $role) = @_; - +sub _concrete_methods_of { + my ($me, $role) = @_; my $info = $INFO{$role}; - - my $methods = $info->{methods} ||= do { + $info->{methods} ||= do { # grab role symbol table my $stash = do { no strict 'refs'; \%{"${role}::"}}; my $not_methods = $info->{not_methods}; @@ -164,9 +195,23 @@ sub _install_methods { 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 + } 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)}, @{$info->{requires}||[]}); +} + +sub _install_methods { + my ($me, $to, $role) = @_; + + my $info = $INFO{$role}; + + my $methods = $me->_concrete_methods_of($role); # grab target symbol table my $stash = do { no strict 'refs'; \%{"${to}::"}}; @@ -174,7 +219,7 @@ sub _install_methods { # determine already extant methods of target my %has_methods; @has_methods{grep - +((ref($stash->{$_}) eq 'SCALAR') || (*{$stash->{$_}}{CODE})), + +(ref($stash->{$_}) || *{$stash->{$_}}{CODE}), keys %$stash } = (); @@ -186,28 +231,226 @@ sub _install_methods { sub _install_modifiers { my ($me, $to, $modifiers) = @_; - foreach my $modifier (@{$modifiers||[]}) { - _install_modifier($to, @{$modifier}); - } -} - -sub _handle_constructor { - my ($me, $to, $attr_info) = @_; - return unless $attr_info && keys %$attr_info; - if ($INFO{$to}) { - @{$INFO{$to}{attributes}||={}}{keys %$attr_info} = values %$attr_info; + if (my $info = $INFO{$to}) { + push @{$info->{modifiers}}, @{$modifiers||[]}; } else { - # only fiddle with the constructor if the target is a Class::Tiny class - if ($INC{"Class/Tiny.pm"} - and my $con = Class::Tiny->_constructor_maker_for($to)) { - $con->register_attribute_specs(%$attr_info); + foreach my $modifier (@{$modifiers||[]}) { + $me->_install_single_modifier($to, @$modifier); } } } +sub _install_single_modifier { + my ($me, @args) = @_; + Class::Method::Modifiers::install_modifier(@args); +} + sub does_role { - my ($package, $role) = @_; - return exists $APPLIED_TO{$package}{$role}; + my ($proto, $role) = @_; + return exists $APPLIED_TO{ref($proto)||$proto}{$role}; } 1; + +=head1 NAME + +Role::Tiny - Roles. Like a nouvelle cuisine portion size slice of Moose. + +=head1 SYNOPSIS + + package Some::Role; + + use Role::Tiny; + + sub foo { ... } + + sub bar { ... } + + around baz => sub { ... } + + 1; + +else where + + package Some::Class; + + use Role::Tiny::With; + + # bar gets imported, but not foo + with 'Some::Role'; + + 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. + +=head1 ROLE COMPOSITION + +Role composition can be thought of as much more clever and meaningful multiple +inheritance. The basics of this implementation of roles is: + +=over 2 + +=item * + +If a method is already defined on a class, that method will not be composed in +from the role. + +=item * + +If a method that the role L to be implemented is not implemented, +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 + +=head1 IMPORTED SUBROUTINES + +=head2 requires + + requires qw(foo bar); + +Declares a list of methods that must be defined to compose role. + +=head2 with + + 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. + +=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 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 are both still convinced that +he's Doing It Wrong. + +=head1 AUTHOR + +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) + +=head1 COPYRIGHT + +Copyright (c) 2010-2012 the Role::Tiny L and L +as listed above. + +=head1 LICENSE + +This library is free software and may be distributed under the same terms +as perl itself. + +=cut