MultiType(3) User Contributed Perl Documentation MultiType(3)

Object::MultiType - Perl Objects as Hash, Array, Scalar, Code and Glob at the same time.

use Object::MultiType ;
my $scalar = 'abc' ;
my @array  = qw(x y z);
my %hash   = (A => 1 , B => 2) ;
my $obj = Object::MultiType->new(
scalar => \$scalar ,
array  => \@array ,
hash   => \%hash ,
code   => sub{ return("I'm a sub ref!") ; }
glob   => \*STDOUT ,
) ;

print "Me as scalar: $obj\n" ;

my $array_1 = $obj->[1] ;
print "$array_1\n" ;

my $hash_B = $obj->{B} ;
print "$hash_B\n" ;

my $hash = $$obj->hash ;
foreach my $Key (sort keys %$hash ) {
  print "$Key = $$hash{$Key}\n" ;
}

&$obj(args) ;

This module return an object that works like a Hash, Array, Scalar, Code and Glob object at the same time.

The usual way is to call it from your module at new():

package FOO ;

use Object::MultiType ;
use vars qw(@ISA) ;
@ISA = qw(Object::MultiType) ; ## Is good to 'Object::MultiType' be the last in @ISA!

sub new {
  my $class = shift ;
  my $this = Object::MultiType->new() ;
  bless($this,$class) ;
}

** See the methods of the Saver too.

Arguments:

The boolean reference. Default: undef
Set the sub/function (CODE reference) that will return/generate the boolean value.
The SCALAR reference. If not sent a null SCALAR will be created.
Set the sub/function (CODE reference) that will return/generate the scalar data of the object.
The ARRAY reference. If not sent a null ARRAY will be created.
The HASH reference. If not sent a null HASH will be created.
The CODE reference. If not sent a null sub{} will be created.

With this your object can be used as a sub reference:

my $multi = Object::MultiType->new( code => sub { print "Args: @_\n" ;} ) ;
&$multi();

Note that the first argument sent to the SUB is the object ($multi).

The GLOB (HANDLE) reference. If not sent a null GLOB will be created.

** Note that you can't use the default (null) GLOB created when you don't paste this argument! Since all the objects will share it, and was there just to avoid erros!

Package name to create a TIEARRAY. The argument $$this is sent to tie().

tie() is called as:

tie(@array,$args{tiearray},$$this) ;

Note that is hard to implement the tie methods for PUSH, POP, SHIFT, UNSHIFT, SPLICE... Unless you make just an alias to another array through the tie methods.

** See tiehash too.

Package name to create a TIEHASH. The argument $$this is sent to tie().

tie() is called as:

tie(%hash,$args{tiehash},$$this) ;

** $$this (the Saver) is sent, and not $this, to avoid the break of DESTROY (auto reference).

** $$this is a reference to the Saver object that save the SCALAR, ARRAY, HASH, CODE and GLOB.

sub TIEHASH {
  my $class = shift ;
  my $multi = shift ; ## $$this
  my $scalarref = $multi->scalar ; ## \${*$multi}
  my $arrayref  = $multi->array  ; ## \@{*$multi}
  my $hashref   = $multi->hash   ; ## \%{*$multi}

  my $this = { s => $scalarref , a => $arrayref , h => $hashref } ;
  bless($this,$class) ;
}
Make the object works like a tied glob (TIEHANDLE).

If used with glob will tie() it. If glob is not sent a NULL GLOB is used:

my $multi = Object::MultiType->new(
glob      => \*MYOUT ,               ## 'glob' is Optional.
tiehandle => 'TieHandlePack' ,
) ;
The reference is only tied when it's used! So, the HASH, ARRAY or GLOB (handle) are only tied if/when they are accessed.
If set to true tell to not create the default references inside the Saver, and it will have only the references paste (scalar, array, hash, code, glob).

** This is good to save memory.

Return 0. Good to see if what you have is the Saver or the MultiType object.

The MultiType object has a Saver object (Object::MultiType::Saver), that save all the different data type (references). This saver can be accessed from the main object:

my $multi = Object::MultiType->new() ;

my $saver = $$multi ;
print $saver->scalar ;

If you want to save attributes in your Object and you use tiehash, you can't set attributes directly in the MultiType object!:

sub new {
  my $class = shift ;
  my $this = Object::MultiType->new(tiehash => 'TieHashPack') ;
  ## Dont do that! This will call the STORE() at TIEHASH, and not save it in the object:
  $this->{flagx} = 1 ;

  bless($this,$class) ;
}

So, if you use tiehash and want to save attributes (outside tie) use that:

## This save the attribute inside the Saver:
$$this->{flagx} = 1 ;

Note that this set an attribute in the saver, and it has their own attributes!

## $saver = $$this ;
$saver->{s} ## the sacalar ref.
$saver->{a} ## the array ref.
$saver->{h} ## the hash ref.
$saver->{c} ## the code ref.  
$saver->{g} ## the glob ref.

** See "Direct access to the data types".

When the object is DESTROIED, the Saver inside it is cleanned, so the tied objects can be DESTROIED automatically too.

To access directly the reference of the different data types (SCALAR, ARRAY, HASH, CODE & GLOB) use:

my $multi = Object::MultiType->new() ;
my $saver = $$multi ;
my $scalarref = $saver->scalar ; ## $saver->{s}
my $arrayref  = $saver->array  ; ## $saver->{a}
my $hashref   = $saver->hash   ; ## $saver->{h}
my $coderef   = $saver->code   ; ## $saver->{c}
my $globeref  = $saver->glob   ; ## $saver->{g}

## You can access the Saver directly from the main object:
$$multi->hash  ;

Setting the data:

$saver->set_bool( 1 ) ;
$saver->set_scalar( 'xyz' ) ;
$saver->set_array( [qw(x y z)] ) ;
$saver->set_hash( {X => 1} ) ;
$saver->set_code( sub{ print "XYZ\n" ; } ) ;
$saver->set_glob( \*STDOUT ) ;

You can use it as SCALAR when you put it inside quotes or make a copy of it:

my $multi = Object::MultiType->new( scalar => 'Foo' ) ;
## Quote:
print "Me as scalar: $multi\n" ;

## Copy:
my $str = $multi ;
$str .= '_x' ; ## Copy made when you change it! Until that $str works like $multi.
print "$str\n" ;

using the argument scalarsub you can use a function that will generate the scalar data, in the place of a reference to a SCALAR:

my $multi = Object::MultiType->new(scalarsub => sub{ return 'generated data' ;} ) ;

print "My scalar have $multi!\n" ;

You can use it as ARRAY directly from the object:

my $multi = Object::MultiType->new( array => [qw(FOO BAR)] ) ;
my $array_0 = $multi->[0] ;
$multi->[1] = 'foo' ;

You can use it as HASH directly from the object:

my $multi = Object::MultiType->new( hash => {key => 'foo'} ) ;
my $k = $multi->{key} ;
$multi->{foo} = 'bar' ;

To use your ARRAY and HASH part tied, you can paste the reference already tied of the HASH or ARRAY, or use the arguments tiehash and tiearray at new():

## Using the reference:
my %hash ;
tie(%hash,'TieHash') ;
my $multi = Object::MultiType->new(hash => \%hash) ;

## Or using directly the argument:
my $multi = Object::MultiType->new(tiehash => 'TieHashPack') ;

Note that using tiehash or tiearray is better, since your tied HASH or ARRAY can see the object Saver and the other data type of it. See the method new() and their arguments.

Here's an example of a TieHash package that is called from Object::MultiType->new():

## The call inside Object::MultiType->new():
tie(%hash,$args{tiehash},$$this) ;

## The package:
package TieHash ;

sub TIEHASH {
    my $class = shift ;
    my $Saver = shift ; ## Object::MultiType paste as $$this (only the Saver) to avoid break of DESTROY!
                        ## $this = Object::MultiType >> $$this = Object::MultiType::Saver

    my $scalarref = $Saver->scalar ;
    my $arrayref  = $Saver->array  ;
    ## Note that $Saver->hash will return the tied hash, and is not needed here!
    ## my $hashref   = $Saver->hash ;

    ## Saving the references inside the TIE object:
    my $this = { scalar => $scalarref , array => $arrayref , hash => {} } ;

    bless($this,$class) ;
}

sub FETCH    { my $this = shift ; return( 'key' ) ;}

sub NEXTKEY  { my $this = shift ; return( 'key' ) ;}

sub STORE    { my $this = shift ; $this->{hash}{$_[0]} = $_[1] }

sub DELETE   { my $this = shift ; delete $this->{hash}{$_[0]} }

sub CLEAR    { my $this = shift ; $this->{hash} = {} ;}

sub EXISTS   { my $this = shift ; defined $this->{hash}{$_[0]} ;}

sub FIRSTKEY { my $this = shift ; (sort keys %{$this->{hash}} )[0] }

sub DESTROY  {}

Using tiehash, you need to save the attributes in the Saver, or you call the tie().

$$this->{flagx} = 1 ;

This is a litte package where the Saver objects are created. It will save the data types (SCALAR, ARRAY, HASH, CODE & GLOB) of the main objects (Object::MultiType).

METHODS:

Return 1. Good to see if what you have is the Saver or the MultiType object.

Return the BOOL reference inside the Saver.

Return the SCALAR reference inside the Saver.

Return the ARRAY reference inside the Saver.

Return the HASH reference inside the Saver.

Return the CODE/sub reference inside the Saver.

Return the GLOB/HANDLE reference inside the Saver.

Set the boolean reference inside the Saver.

Set the SCALAR reference inside the Saver.

Set the ARRAY reference inside the Saver.

Set the HASH reference inside the Saver.

Set the CODE/sub reference inside the Saver.

Set the GLOB/HANDLE reference inside the Saver.

Clean all the references saved in the Saver.

overload, perltie, Scalar::Util.

This module/class was created for XML::Smart.

Graciliano M. P. <gm@virtuasites.com.br>

I will appreciate any type of feedback (include your opinions and/or suggestions). ;-P

This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

2022-05-29 perl v5.36.0