Tag Styles

You can define the style of tags you want to support:

my $yp_perl_two_one = YAML::PP->new(
    schema => [qw/ + Perl tags=!!perl+!perl /],
);

"!perl" (default)

Only "!perl/type" tags are supported.

"!!perl"

Only "!!perl/type" tags are supported.

"!perl+!!perl"

Both "!perl/type" and "!!perl/tag" are supported when loading. When dumping, "!perl/type" is used.

"!!perl+!perl"

Both "!perl/type" and "!!perl/tag" are supported when loading. When dumping, "!!perl/type" is used.

YAML.pm, YAML::Syck and YAML::XS are using "!!perl/type" when dumping.

YAML.pm and YAML::Syck are supporting both "!perl/type" and "!!perl/type" when loading. YAML::XS currently only supports the latter.

Allow only certain classes

Since v0.017

Blessing arbitrary objects can be dangerous. Maybe you want to allow blessing only specific classes and ignore others. For this you have to instantiate a Perl Schema object first and use the "classes" option.

Currently it only allows a list of strings:

my $perl = YAML::PP::Schema::Perl->new(
    classes => ['Foo', 'Bar'],
);
my $yp = YAML::PP::Perl->new(
    schema => [qw/ + /, $perl],
);

Allowed classes will be loaded and dumped as usual. The others will be ignored.

If you want to allow no objects at all, pass an empty array ref.

EXAMPLES

This is a list of the currently supported types and how they are dumped into YAML:

array

# Code
[
    qw/ one two three four /
]
# YAML
---
- one
- two
- three
- four

array_blessed

# Code
bless [
    qw/ one two three four /
], "Just::An::Arrayref"
# YAML
--- !perl/array:Just::An::Arrayref
- one
- two
- three
- four

circular

# Code
my $circle = bless [ 1, 2 ], 'Circle';
push @$circle, $circle;
$circle;
# YAML
--- &1 !perl/array:Circle
- 1
- 2
- *1

coderef

# Code
sub {
    my (%args) = @_;
    return $args{x} + $args{y};
}
# YAML
--- !perl/code |-
  {
      use warnings;
      use strict;
      (my(%args) = @_);
      (return ($args{'x'} + $args{'y'}));
  }

coderef_blessed

# Code
bless sub {
    my (%args) = @_;
    return $args{x} - $args{y};
}, "I::Am::Code"
# YAML
--- !perl/code:I::Am::Code |-
  {
      use warnings;
      use strict;
      (my(%args) = @_);
      (return ($args{'x'} - $args{'y'}));
  }

hash

# Code
{
    U => 2,
    B => 52,
}
# YAML
---
B: 52
U: 2

hash_blessed

# Code
bless {
    U => 2,
    B => 52,
}, 'A::Very::Exclusive::Class'
# YAML
--- !perl/hash:A::Very::Exclusive::Class
B: 52
U: 2

refref

# Code
my $ref = { a => 'hash' };
my $refref = \$ref;
$refref;
# YAML
--- !perl/ref
=:
  a: hash

refref_blessed

# Code
my $ref = { a => 'hash' };
my $refref = bless \$ref, 'Foo';
$refref;
# YAML
--- !perl/ref:Foo
=:
  a: hash

regexp

# Code
my $string = 'unblessed';
qr{$string}
# YAML
--- !perl/regexp unblessed

regexp_blessed

# Code
my $string = 'blessed';
bless qr{$string}, "Foo"
# YAML
--- !perl/regexp:Foo blessed

scalarref

# Code
my $scalar = "some string";
my $scalarref = \$scalar;
$scalarref;
# YAML
--- !perl/scalar
=: some string

scalarref_blessed

# Code
my $scalar = "some other string";
my $scalarref = bless \$scalar, 'Foo';
$scalarref;
# YAML
--- !perl/scalar:Foo
=: some other string

METHODS

new

my $perl = YAML::PP::Schema::Perl->new(
    tags => "!perl",
    classes => ['MyClass'],
    loadcode => 1,
    dumpcode => 1,
);

The constructor recognizes the following options:

register

A class method called by YAML::PP::Schema

construct_ref, represent_ref

Perl variables of the type "REF" are represented in yaml like this:

--- !perl/ref
=:
  a: 1

"construct_ref" returns the perl data:

my $data = YAML::PP::Schema::Perl->construct_ref([ '=', { some => 'data' } );
my $data = \{ a => 1 };

"represent_ref" turns a "REF" variable into a YAML mapping:

my $data = YAML::PP::Schema::Perl->represent_ref(\{ a => 1 });
my $data = { '=' => { a => 1 } };

construct_scalar, represent_scalar

Perl variables of the type "SCALAR" are represented in yaml like this:

--- !perl/scalar
=: string

"construct_scalar" returns the perl data:

my $data = YAML::PP::Schema::Perl->construct_ref([ '=', 'string' );
my $data = \'string';

"represent_scalar" turns a "SCALAR" variable into a YAML mapping:

my $data = YAML::PP::Schema::Perl->represent_scalar(\'string');
my $data = { '=' => 'string' };

construct_regex, represent_regex

"construct_regex" returns a "qr{}" object from the YAML string:

my $qr = YAML::PP::Schema::Perl->construct_regex('foo.*');

"represent_regex" returns a string representing the regex object:

my $string = YAML::PP::Schema::Perl->represent_regex(qr{...});

evaluate_code, represent_code

"evaluate_code" returns a code reference from a string. The string must start with a "{" and end with a "}".

my $code = YAML::PP::Schema::Perl->evaluate_code('{ return 23 }');

"represent_code" returns a string representation of the code reference with the help of B::Deparse:

my $string = YAML::PP::Schema::Perl->represent_code(sub { return 23 });

construct_glob, represent_glob

"construct_glob" returns a glob from a hash.

my $glob = YAML::PP::Schema::Perl->construct_glob($hash);

"represent_glob" returns a hash representation of the glob.

my $hash = YAML::PP::Schema::Perl->represent_glob($glob);

object

Does the same as "bless":

my $object = YAML::PP::Schema::Perl->object($data, $class);