libobject-insideout-perl 4.04-1 / usr / share / perl5 / Object / InsideOut / lvalue.pm

package Object::InsideOut; {

use strict;
use warnings;
no warnings 'redefine';

# Create an :lvalue accessor method
sub create_lvalue_accessor
{
    if ($] < 5.008) {
        my ($pkg, $set) = @_;
        OIO::Code->die(
            'message' => "Can't create 'lvalue' accessor method '$set' for package '$pkg'",
            'Info'    => q/'lvalue' accessors require Perl 5.8.0 or later/);
    }

    eval { require Want; };
    if ($@) {
        my ($pkg, $set) = @_;
        OIO::Code->die(
            'message' => "Can't create 'lvalue' accessor method '$set' for package '$pkg'",
            'Info'    => q/Failure loading 'Want' module/,
            'Error'   => $@);
    } elsif ($Want::VERSION < 0.12) {
        my ($pkg, $set) = @_;
        OIO::Code->die(
            'message' => "Can't create 'lvalue' accessor method '$set' for package '$pkg'",
            'Info'    => q/Requires 'Want' v0.12 or later/);
    }

    *Object::InsideOut::create_lvalue_accessor = sub
    {
        my $caller = caller();
        if ($caller ne 'Object::InsideOut') {
            OIO::Method->die('message' => "Can't call private subroutine 'Object::InsideOut::create_lvalue_accessor' from class '$caller'");
        }

        my ($pkg, $set, $field_ref, $get, $type, $is_ref, $subtype,
            $name, $return, $private, $restricted, $weak, $pre) = @_;

        # Field string
        my $fld_str = (ref($field_ref) eq 'HASH') ? "\$field->\{\${\$_[0]}}" : "\$field->\[\${\$_[0]}]";

        # 'Want object' string
        my $obj_str = q/(Want::wantref() eq 'OBJECT')/;

        # Begin with subroutine declaration in the appropriate package
        my $code = "*${pkg}::$set = sub :lvalue {\n"
                 . preamble_code($pkg, $set, $private, $restricted)
                 . "    my \$rv = !Want::want_lvalue(0);\n";

        # Add GET portion for combination accessor
        if ($get && ($get eq $set)) {
            $code .= "    Want::rreturn($fld_str) if (\$rv && (\@_ == 1));\n";
        }

        # If set only, then must have at least one arg
        else {
            $code .= <<"_CHECK_ARGS_";
    my \$wobj = $obj_str;
    if ((\@_ < 2) && (\$rv || \$wobj)) {
        OIO::Args->die(
            'message'  => q/Missing arg(s) to '$pkg->$set'/,
            'location' => [ caller() ]);
    }
_CHECK_ARGS_
            $obj_str = '$wobj';
        }

        # Add field locking code if sharing
        if (is_sharing($pkg)) {
            $code .= "    lock(\$field);\n"
        }

        # Return value for 'OLD'
        if ($return eq 'OLD') {
            $code .= "    my \$ret;\n";
        }

        # Get args if assignment
        $code .= <<"_SET_";
    my \$assign;
    if (my \@args = Want::wantassign(1)) {
        \@_ = (\$_[0], \@args);
        \$assign = 1;
    }
    if (\@_ > 1) {
_SET_

        # Add preprocessing code block
        if ($pre) {
            $code .= <<"_PRE_";
        {
            my \@errs;
            local \$SIG{'__WARN__'} = sub { push(\@errs, \@_); };
            eval {
                my \$self = shift;
                \@_ = (\$self, \$preproc->(\$self, \$field, \@_));
            };
            if (\$@ || \@errs) {
                my (\$err) = split(/ at /, \$@ || join(" | ", \@errs));
                OIO::Code->die(
                    'message' => q/Problem with preprocessing routine for '$pkg->$set'/,
                    'Error'   => \$err);
            }
        }
_PRE_
        }

        # Add data type checking
        my ($type_code, $arg_str) = type_code($pkg, $set, $weak,
                                              $type, $is_ref, $subtype);
        $code .= $type_code;

        # Grab 'OLD' value
        if ($return eq 'OLD') {
            $code .= "        \$ret = $fld_str;\n";
        }

        # Add actual 'set' code
        $code .= (is_sharing($pkg))
              ? "        $fld_str = Object::InsideOut::Util::make_shared($arg_str);\n"
              : "        $fld_str = $arg_str;\n";
        if ($weak) {
            $code .= "        Scalar::Util::weaken($fld_str);\n";
        }

        # Add code for return value
        $code     .= "        Want::lnoreturn if \$assign;\n";
        if ($return eq 'SELF') {
            $code .= "        Want::rreturn(\$_[0]) if \$rv;\n";
        } elsif ($return eq 'OLD') {
            $code .= "        Want::rreturn(\$ret) if \$rv;\n";
        } else {
            $code .= "        Want::rreturn($fld_str) if \$rv;\n";
        }
        $code .= "    }\n";

        if ($return eq 'SELF') {
            $code .= "    (\@_ < 2) ? $fld_str : \$_[0];\n";
        } elsif ($return eq 'OLD') {
            $code .= "    (\@_ < 2) ? $fld_str : (($obj_str && !Scalar::Util::blessed(\$ret)) ? \$_[0] : \$ret);\n";
        } else {
            $code .= "    ((\@_ > 1) && $obj_str && !Scalar::Util::blessed($fld_str)) ? \$_[0] : $fld_str;\n";
        }
        $code .= "};\n";

        # Done
        return ($code);
    };

    # Do the original call
    goto &create_lvalue_accessor;
}

}  # End of package's lexical scope


# Ensure correct versioning
($Object::InsideOut::VERSION eq '4.04')
    or die("Version mismatch\n");

# EOF