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inc/Spiffy.pm  view on Meta::CPAN

}

my %code = ( 
    sub_start => 
      "sub {\n",
    set_default => 
      "  \$_[0]->{%s} = %s\n    unless exists \$_[0]->{%s};\n",
    init =>
      "  return \$_[0]->{%s} = do { my \$self = \$_[0]; %s }\n" .
      "    unless \$#_ > 0 or defined \$_[0]->{%s};\n",
    weak_init =>
      "  return do {\n" .
      "    \$_[0]->{%s} = do { my \$self = \$_[0]; %s };\n" .
      "    Scalar::Util::weaken(\$_[0]->{%s}) if ref \$_[0]->{%s};\n" .
      "    \$_[0]->{%s};\n" .
      "  } unless \$#_ > 0 or defined \$_[0]->{%s};\n",
    return_if_get => 
      "  return \$_[0]->{%s} unless \$#_ > 0;\n",
    set => 
      "  \$_[0]->{%s} = \$_[1];\n",
    weaken => 
      "  Scalar::Util::weaken(\$_[0]->{%s}) if ref \$_[0]->{%s};\n",
    sub_end => 
      "  return \$_[0]->{%s};\n}\n",
);

sub field {
    my $package = caller;
    my ($args, @values) = do {
        no warnings;
        local *boolean_arguments = sub { (qw(-weak)) };
        local *paired_arguments = sub { (qw(-package -init)) };
        Spiffy->parse_arguments(@_);
    };
    my ($field, $default) = @values;
    $package = $args->{-package} if defined $args->{-package};
    die "Cannot have a default for a weakened field ($field)"
        if defined $default && $args->{-weak};
    return if defined &{"${package}::$field"};
    require Scalar::Util if $args->{-weak};
    my $default_string =
        ( ref($default) eq 'ARRAY' and not @$default )
        ? '[]'
        : (ref($default) eq 'HASH' and not keys %$default )
          ? '{}'
          : default_as_code($default);

    my $code = $code{sub_start};
    if ($args->{-init}) {
        my $fragment = $args->{-weak} ? $code{weak_init} : $code{init};
        $code .= sprintf $fragment, $field, $args->{-init}, ($field) x 4;
    }
    $code .= sprintf $code{set_default}, $field, $default_string, $field
      if defined $default;
    $code .= sprintf $code{return_if_get}, $field;
    $code .= sprintf $code{set}, $field;
    $code .= sprintf $code{weaken}, $field, $field 
      if $args->{-weak};
    $code .= sprintf $code{sub_end}, $field;

    my $sub = eval $code;
    die $@ if $@;
    no strict 'refs';
    *{"${package}::$field"} = $sub;
    return $code if defined wantarray;
}

sub default_as_code {
    require Data::Dumper;
    local $Data::Dumper::Sortkeys = 1;
    my $code = Data::Dumper::Dumper(shift);
    $code =~ s/^\$VAR1 = //;
    $code =~ s/;$//;
    return $code;
}

sub const {
    my $package = caller;
    my ($args, @values) = do {
        no warnings;
        local *paired_arguments = sub { (qw(-package)) };
        Spiffy->parse_arguments(@_);
    };
    my ($field, $default) = @values;
    $package = $args->{-package} if defined $args->{-package};
    no strict 'refs';
    return if defined &{"${package}::$field"};
    *{"${package}::$field"} = sub { $default }
}

sub stub {
    my $package = caller;
    my ($args, @values) = do {
        no warnings;
        local *paired_arguments = sub { (qw(-package)) };
        Spiffy->parse_arguments(@_);
    };
    my ($field, $default) = @values;
    $package = $args->{-package} if defined $args->{-package};
    no strict 'refs';
    return if defined &{"${package}::$field"};
    *{"${package}::$field"} = 
    sub { 
        require Carp;
        Carp::confess 
          "Method $field in package $package must be subclassed";
    }
}

sub parse_arguments {
    my $class = shift;
    my ($args, @values) = ({}, ());
    my %booleans = map { ($_, 1) } $class->boolean_arguments;
    my %pairs = map { ($_, 1) } $class->paired_arguments;
    while (@_) {
        my $elem = shift;
        if (defined $elem and defined $booleans{$elem}) {
            $args->{$elem} = (@_ and $_[0] =~ /^[01]$/)
            ? shift
            : 1;
        }

inc/Spiffy.pm  view on Meta::CPAN

package Spiffy;
sub super {
    my $method;
    my $frame = 1;
    while ($method = (caller($frame++))[3]) {
        $method =~ s/.*::// and last;
    }
    my @args = DB::super_args($frame);
    @_ = @_ ? ($args[0], @_) : @args;
    my $class = ref $_[0] ? ref $_[0] : $_[0];
    my $caller_class = caller;
    my $seen = 0;
    my @super_classes = reverse grep {
        ($seen or $seen = ($_ eq $caller_class)) ? 0 : 1;
    } reverse @{all_my_bases($class)};
    for my $super_class (@super_classes) {
        no strict 'refs';
        next if $super_class eq $class;
        if (defined &{"${super_class}::$method"}) {
            ${"$super_class\::AUTOLOAD"} = ${"$class\::AUTOLOAD"}
              if $method eq 'AUTOLOAD';
            return &{"${super_class}::$method"};
        }
    }
    return;
}

#===============================================================================
# This code deserves a spanking, because it is being very naughty.
# It is exchanging base.pm's import() for its own, so that people
# can use base.pm with Spiffy modules, without being the wiser.
#===============================================================================
my $real_base_import;
my $real_mixin_import;

BEGIN {
    require base unless defined $INC{'base.pm'};
    $INC{'mixin.pm'} ||= 'Spiffy/mixin.pm';
    $real_base_import = \&base::import;
    $real_mixin_import = \&mixin::import;
    no warnings;
    *base::import = \&spiffy_base_import;
    *mixin::import = \&spiffy_mixin_import;
}

# my $i = 0;
# while (my $caller = caller($i++)) {
#     next unless $caller eq 'base' or $caller eq 'mixin';
#     croak <<END;
# Spiffy.pm must be loaded before calling 'use base' or 'use mixin' with a
# Spiffy module. See the documentation of Spiffy.pm for details.
# END
# }

sub spiffy_base_import {
    my @base_classes = @_;
    shift @base_classes;
    no strict 'refs';
    goto &$real_base_import
      unless grep {
          eval "require $_" unless %{"$_\::"};
          $_->isa('Spiffy');
      } @base_classes;
    my $inheritor = caller(0);
    for my $base_class (@base_classes) {
        next if $inheritor->isa($base_class);
        croak "Can't mix Spiffy and non-Spiffy classes in 'use base'.\n", 
              "See the documentation of Spiffy.pm for details\n  "
          unless $base_class->isa('Spiffy');
        $stack_frame = 1; # tell import to use different caller
        import($base_class, '-base');
        $stack_frame = 0;
    }
}

sub mixin {
    my $self = shift;
    my $target_class = ref($self);
    spiffy_mixin_import($target_class, @_)
}

sub spiffy_mixin_import {
    my $target_class = shift;
    $target_class = caller(0)
      if $target_class eq 'mixin';
    my $mixin_class = shift
      or die "Nothing to mixin";
    eval "require $mixin_class";
    my @roles = @_;
    my $pseudo_class = join '-', $target_class, $mixin_class, @roles;
    my %methods = spiffy_mixin_methods($mixin_class, @roles);
    no strict 'refs';
    no warnings;
    @{"$pseudo_class\::ISA"} = @{"$target_class\::ISA"};
    @{"$target_class\::ISA"} = ($pseudo_class);
    for (keys %methods) {
        *{"$pseudo_class\::$_"} = $methods{$_};
    }
}

sub spiffy_mixin_methods {
    my $mixin_class = shift;
    no strict 'refs';
    my %methods = spiffy_all_methods($mixin_class);
    map {
        $methods{$_}
          ? ($_, \ &{"$methods{$_}\::$_"})
          : ($_, \ &{"$mixin_class\::$_"})
    } @_ 
      ? (get_roles($mixin_class, @_))
      : (keys %methods);
}

sub get_roles {
    my $mixin_class = shift;
    my @roles = @_;
    while (grep /^!*:/, @roles) {
        @roles = map {
            s/!!//g;
            /^!:(.*)/ ? do { 
                my $m = "_role_$1"; 
                map("!$_", $mixin_class->$m);
            } :
            /^:(.*)/ ? do {
                my $m = "_role_$1"; 
                ($mixin_class->$m);
            } :
            ($_)
        } @roles;
    }
    if (@roles and $roles[0] =~ /^!/) {
        my %methods = spiffy_all_methods($mixin_class);
        unshift @roles, keys(%methods);
    }
    my %roles;
    for (@roles) {
        s/!!//g;
        delete $roles{$1}, next
          if /^!(.*)/;
        $roles{$_} = 1;
    }
    keys %roles;
}

sub spiffy_all_methods {
    no strict 'refs';
    my $class = shift;
    return if $class eq 'Spiffy';