NAME

Venus::Undef - Undef Class

ABSTRACT

Undef Class for Perl 5

SYNOPSIS

package main;

use Venus::Undef;

my $undef = Venus::Undef->new;

# $undef->defined;

DESCRIPTION

This package provides methods for manipulating undef data.

INHERITS

This package inherits behaviors from:

Venus::Kind::Value

METHODS

This package provides the following methods:

cast

cast(string $kind) (object | undef)

The cast method converts "value" objects between different "value" object types, based on the name of the type provided. This method will return undef if the invocant is not a Venus::Kind::Value.

Since 0.08

cast example 1
package main;

use Venus::Undef;

my $undef = Venus::Undef->new;

my $cast = $undef->cast('array');

# bless({ value => [undef] }, "Venus::Array")
cast example 2
package main;

use Venus::Undef;

my $undef = Venus::Undef->new;

my $cast = $undef->cast('boolean');

# bless({ value => 0 }, "Venus::Boolean")
cast example 3
package main;

use Venus::Undef;

my $undef = Venus::Undef->new;

my $cast = $undef->cast('code');

# bless({ value => sub { ... } }, "Venus::Code")
cast example 4
package main;

use Venus::Undef;

my $undef = Venus::Undef->new;

my $cast = $undef->cast('float');

# bless({ value => "0.0" }, "Venus::Float")
cast example 5
package main;

use Venus::Undef;

my $undef = Venus::Undef->new;

my $cast = $undef->cast('hash');

# bless({ value => {} }, "Venus::Hash")
cast example 6
package main;

use Venus::Undef;

my $undef = Venus::Undef->new;

my $cast = $undef->cast('number');

# bless({ value => 0 }, "Venus::Number")
cast example 7
package main;

use Venus::Undef;

my $undef = Venus::Undef->new;

my $cast = $undef->cast('regexp');

# bless({ value => qr/(?^u:)/ }, "Venus::Regexp")
cast example 8
package main;

use Venus::Undef;

my $undef = Venus::Undef->new;

my $cast = $undef->cast('scalar');

# bless({ value => \"" }, "Venus::Scalar")
cast example 9
package main;

use Venus::Undef;

my $undef = Venus::Undef->new;

my $cast = $undef->cast('string');

# bless({ value => "" }, "Venus::String")
cast example 10
package main;

use Venus::Undef;

my $undef = Venus::Undef->new;

my $cast = $undef->cast('undef');

# bless({ value => undef }, "Venus::Undef")

default

default() (undef)

The default method returns the default value, i.e. undef.

Since 0.01

default example 1
# given: synopsis;

my $default = $undef->default;

# undef

eq

eq(any $arg) (boolean)

The eq method performs an "equals" operation using the argument provided.

Since 0.08

eq example 1
package main;

use Venus::Array;
use Venus::Undef;

my $lvalue = Venus::Undef->new;
my $rvalue = Venus::Array->new;

my $result = $lvalue->eq($rvalue);

# 0
eq example 2
package main;

use Venus::Code;
use Venus::Undef;

my $lvalue = Venus::Undef->new;
my $rvalue = Venus::Code->new;

my $result = $lvalue->eq($rvalue);

# 0
eq example 3
package main;

use Venus::Float;
use Venus::Undef;

my $lvalue = Venus::Undef->new;
my $rvalue = Venus::Float->new;

my $result = $lvalue->eq($rvalue);

# 1
eq example 4
package main;

use Venus::Hash;
use Venus::Undef;

my $lvalue = Venus::Undef->new;
my $rvalue = Venus::Hash->new;

my $result = $lvalue->eq($rvalue);

# 0
eq example 5
package main;

use Venus::Number;
use Venus::Undef;

my $lvalue = Venus::Undef->new;
my $rvalue = Venus::Number->new;

my $result = $lvalue->eq($rvalue);

# 1
eq example 6
package main;

use Venus::Regexp;
use Venus::Undef;

my $lvalue = Venus::Undef->new;
my $rvalue = Venus::Regexp->new;

my $result = $lvalue->eq($rvalue);

# 0
eq example 7
package main;

use Venus::Scalar;
use Venus::Undef;

my $lvalue = Venus::Undef->new;
my $rvalue = Venus::Scalar->new;

my $result = $lvalue->eq($rvalue);

# 0
eq example 8
package main;

use Venus::String;
use Venus::Undef;

my $lvalue = Venus::Undef->new;
my $rvalue = Venus::String->new;

my $result = $lvalue->eq($rvalue);

# 1
eq example 9
package main;

use Venus::Undef;

my $lvalue = Venus::Undef->new;
my $rvalue = Venus::Undef->new;

my $result = $lvalue->eq($rvalue);

# 1

ge

ge(any $arg) (boolean)

The ge method performs a "greater-than-or-equal-to" operation using the argument provided.

Since 0.08

ge example 1
package main;

use Venus::Array;
use Venus::Undef;

my $lvalue = Venus::Undef->new;
my $rvalue = Venus::Array->new;

my $result = $lvalue->ge($rvalue);

# 0
ge example 2
package main;

use Venus::Code;
use Venus::Undef;

my $lvalue = Venus::Undef->new;
my $rvalue = Venus::Code->new;

my $result = $lvalue->ge($rvalue);

# 0
ge example 3
package main;

use Venus::Float;
use Venus::Undef;

my $lvalue = Venus::Undef->new;
my $rvalue = Venus::Float->new;

my $result = $lvalue->ge($rvalue);

# 1
ge example 4
package main;

use Venus::Hash;
use Venus::Undef;

my $lvalue = Venus::Undef->new;
my $rvalue = Venus::Hash->new;

my $result = $lvalue->ge($rvalue);

# 0
ge example 5
package main;

use Venus::Number;
use Venus::Undef;

my $lvalue = Venus::Undef->new;
my $rvalue = Venus::Number->new;

my $result = $lvalue->ge($rvalue);

# 1
ge example 6
package main;

use Venus::Regexp;
use Venus::Undef;

my $lvalue = Venus::Undef->new;
my $rvalue = Venus::Regexp->new;

my $result = $lvalue->ge($rvalue);

# 0
ge example 7
package main;

use Venus::Scalar;
use Venus::Undef;

my $lvalue = Venus::Undef->new;
my $rvalue = Venus::Scalar->new;

my $result = $lvalue->ge($rvalue);

# 0
ge example 8
package main;

use Venus::String;
use Venus::Undef;

my $lvalue = Venus::Undef->new;
my $rvalue = Venus::String->new;

my $result = $lvalue->ge($rvalue);

# 1
ge example 9
package main;

use Venus::Undef;

my $lvalue = Venus::Undef->new;
my $rvalue = Venus::Undef->new;

my $result = $lvalue->ge($rvalue);

# 1

gele

gele(any $arg1, any $arg2) (boolean)

The gele method performs a "greater-than-or-equal-to" operation on the 1st argument, and "lesser-than-or-equal-to" operation on the 2nd argument.

Since 0.08

gele example 1
package main;

use Venus::Array;
use Venus::Undef;

my $lvalue = Venus::Undef->new;
my $rvalue = Venus::Array->new;

my $result = $lvalue->gele($rvalue);

# 0
gele example 2
package main;

use Venus::Code;
use Venus::Undef;

my $lvalue = Venus::Undef->new;
my $rvalue = Venus::Code->new;

my $result = $lvalue->gele($rvalue);

# 0
gele example 3
package main;

use Venus::Float;
use Venus::Undef;

my $lvalue = Venus::Undef->new;
my $rvalue = Venus::Float->new;

my $result = $lvalue->gele($rvalue);

# 1
gele example 4
package main;

use Venus::Hash;
use Venus::Undef;

my $lvalue = Venus::Undef->new;
my $rvalue = Venus::Hash->new;

my $result = $lvalue->gele($rvalue);

# 0
gele example 5
package main;

use Venus::Number;
use Venus::Undef;

my $lvalue = Venus::Undef->new;
my $rvalue = Venus::Number->new;

my $result = $lvalue->gele($rvalue);

# 1
gele example 6
package main;

use Venus::Regexp;
use Venus::Undef;

my $lvalue = Venus::Undef->new;
my $rvalue = Venus::Regexp->new;

my $result = $lvalue->gele($rvalue);

# 0
gele example 7
package main;

use Venus::Scalar;
use Venus::Undef;

my $lvalue = Venus::Undef->new;
my $rvalue = Venus::Scalar->new;

my $result = $lvalue->gele($rvalue);

# 0
gele example 8
package main;

use Venus::String;
use Venus::Undef;

my $lvalue = Venus::Undef->new;
my $rvalue = Venus::String->new;

my $result = $lvalue->gele($rvalue);

# 1
gele example 9
package main;

use Venus::Undef;

my $lvalue = Venus::Undef->new;
my $rvalue = Venus::Undef->new;

my $result = $lvalue->gele($rvalue);

# 1

gt

gt(any $arg) (boolean)

The gt method performs a "greater-than" operation using the argument provided.

Since 0.08

gt example 1
package main;

use Venus::Array;
use Venus::Undef;

my $lvalue = Venus::Undef->new;
my $rvalue = Venus::Array->new;

my $result = $lvalue->gt($rvalue);

# 0
gt example 2
package main;

use Venus::Code;
use Venus::Undef;

my $lvalue = Venus::Undef->new;
my $rvalue = Venus::Code->new;

my $result = $lvalue->gt($rvalue);

# 0
gt example 3
package main;

use Venus::Float;
use Venus::Undef;

my $lvalue = Venus::Undef->new;
my $rvalue = Venus::Float->new;

my $result = $lvalue->gt($rvalue);

# 0
gt example 4
package main;

use Venus::Hash;
use Venus::Undef;

my $lvalue = Venus::Undef->new;
my $rvalue = Venus::Hash->new;

my $result = $lvalue->gt($rvalue);

# 0
gt example 5
package main;

use Venus::Number;
use Venus::Undef;

my $lvalue = Venus::Undef->new;
my $rvalue = Venus::Number->new;

my $result = $lvalue->gt($rvalue);

# 0
gt example 6
package main;

use Venus::Regexp;
use Venus::Undef;

my $lvalue = Venus::Undef->new;
my $rvalue = Venus::Regexp->new;

my $result = $lvalue->gt($rvalue);

# 0
gt example 7
package main;

use Venus::Scalar;
use Venus::Undef;

my $lvalue = Venus::Undef->new;
my $rvalue = Venus::Scalar->new;

my $result = $lvalue->gt($rvalue);

# 0
gt example 8
package main;

use Venus::String;
use Venus::Undef;

my $lvalue = Venus::Undef->new;
my $rvalue = Venus::String->new;

my $result = $lvalue->gt($rvalue);

# 0
gt example 9
package main;

use Venus::Undef;

my $lvalue = Venus::Undef->new;
my $rvalue = Venus::Undef->new;

my $result = $lvalue->gt($rvalue);

# 0

gtlt

gtlt(any $arg1, any $arg2) (boolean)

The gtlt method performs a "greater-than" operation on the 1st argument, and "lesser-than" operation on the 2nd argument.

Since 0.08

gtlt example 1
package main;

use Venus::Array;
use Venus::Undef;

my $lvalue = Venus::Undef->new;
my $rvalue = Venus::Array->new;

my $result = $lvalue->gtlt($rvalue);

# 0
gtlt example 2
package main;

use Venus::Code;
use Venus::Undef;

my $lvalue = Venus::Undef->new;
my $rvalue = Venus::Code->new;

my $result = $lvalue->gtlt($rvalue);

# 0
gtlt example 3
package main;

use Venus::Float;
use Venus::Undef;

my $lvalue = Venus::Undef->new;
my $rvalue = Venus::Float->new;

my $result = $lvalue->gtlt($rvalue);

# 0
gtlt example 4
package main;

use Venus::Hash;
use Venus::Undef;

my $lvalue = Venus::Undef->new;
my $rvalue = Venus::Hash->new;

my $result = $lvalue->gtlt($rvalue);

# 0
gtlt example 5
package main;

use Venus::Number;
use Venus::Undef;

my $lvalue = Venus::Undef->new;
my $rvalue = Venus::Number->new;

my $result = $lvalue->gtlt($rvalue);

# 0
gtlt example 6
package main;

use Venus::Regexp;
use Venus::Undef;

my $lvalue = Venus::Undef->new;
my $rvalue = Venus::Regexp->new;

my $result = $lvalue->gtlt($rvalue);

# 0
gtlt example 7
package main;

use Venus::Scalar;
use Venus::Undef;

my $lvalue = Venus::Undef->new;
my $rvalue = Venus::Scalar->new;

my $result = $lvalue->gtlt($rvalue);

# 0
gtlt example 8
package main;

use Venus::String;
use Venus::Undef;

my $lvalue = Venus::Undef->new;
my $rvalue = Venus::String->new;

my $result = $lvalue->gtlt($rvalue);

# 0
gtlt example 9
package main;

use Venus::Undef;

my $lvalue = Venus::Undef->new;
my $rvalue = Venus::Undef->new;

my $result = $lvalue->gtlt($rvalue);

# 0

le

le(any $arg) (boolean)

The le method performs a "lesser-than-or-equal-to" operation using the argument provided.

Since 0.08

le example 1
package main;

use Venus::Array;
use Venus::Undef;

my $lvalue = Venus::Undef->new;
my $rvalue = Venus::Array->new;

my $result = $lvalue->le($rvalue);

# 1
le example 2
package main;

use Venus::Code;
use Venus::Undef;

my $lvalue = Venus::Undef->new;
my $rvalue = Venus::Code->new;

my $result = $lvalue->le($rvalue);

# 1
le example 3
package main;

use Venus::Float;
use Venus::Undef;

my $lvalue = Venus::Undef->new;
my $rvalue = Venus::Float->new;

my $result = $lvalue->le($rvalue);

# 1
le example 4
package main;

use Venus::Hash;
use Venus::Undef;

my $lvalue = Venus::Undef->new;
my $rvalue = Venus::Hash->new;

my $result = $lvalue->le($rvalue);

# 1
le example 5
package main;

use Venus::Number;
use Venus::Undef;

my $lvalue = Venus::Undef->new;
my $rvalue = Venus::Number->new;

my $result = $lvalue->le($rvalue);

# 1
le example 6
package main;

use Venus::Regexp;
use Venus::Undef;

my $lvalue = Venus::Undef->new;
my $rvalue = Venus::Regexp->new;

my $result = $lvalue->le($rvalue);

# 1
le example 7
package main;

use Venus::Scalar;
use Venus::Undef;

my $lvalue = Venus::Undef->new;
my $rvalue = Venus::Scalar->new;

my $result = $lvalue->le($rvalue);

# 1
le example 8
package main;

use Venus::String;
use Venus::Undef;

my $lvalue = Venus::Undef->new;
my $rvalue = Venus::String->new;

my $result = $lvalue->le($rvalue);

# 1
le example 9
package main;

use Venus::Undef;

my $lvalue = Venus::Undef->new;
my $rvalue = Venus::Undef->new;

my $result = $lvalue->le($rvalue);

# 1

lt

lt(any $arg) (boolean)

The lt method performs a "lesser-than" operation using the argument provided.

Since 0.08

lt example 1
package main;

use Venus::Array;
use Venus::Undef;

my $lvalue = Venus::Undef->new;
my $rvalue = Venus::Array->new;

my $result = $lvalue->lt($rvalue);

# 1
lt example 2
package main;

use Venus::Code;
use Venus::Undef;

my $lvalue = Venus::Undef->new;
my $rvalue = Venus::Code->new;

my $result = $lvalue->lt($rvalue);

# 1
lt example 3
package main;

use Venus::Float;
use Venus::Undef;

my $lvalue = Venus::Undef->new;
my $rvalue = Venus::Float->new;

my $result = $lvalue->lt($rvalue);

# 0
lt example 4
package main;

use Venus::Hash;
use Venus::Undef;

my $lvalue = Venus::Undef->new;
my $rvalue = Venus::Hash->new;

my $result = $lvalue->lt($rvalue);

# 1
lt example 5
package main;

use Venus::Number;
use Venus::Undef;

my $lvalue = Venus::Undef->new;
my $rvalue = Venus::Number->new;

my $result = $lvalue->lt($rvalue);

# 0
lt example 6
package main;

use Venus::Regexp;
use Venus::Undef;

my $lvalue = Venus::Undef->new;
my $rvalue = Venus::Regexp->new;

my $result = $lvalue->lt($rvalue);

# 1
lt example 7
package main;

use Venus::Scalar;
use Venus::Undef;

my $lvalue = Venus::Undef->new;
my $rvalue = Venus::Scalar->new;

my $result = $lvalue->lt($rvalue);

# 1
lt example 8
package main;

use Venus::String;
use Venus::Undef;

my $lvalue = Venus::Undef->new;
my $rvalue = Venus::String->new;

my $result = $lvalue->lt($rvalue);

# 0
lt example 9
package main;

use Venus::Undef;

my $lvalue = Venus::Undef->new;
my $rvalue = Venus::Undef->new;

my $result = $lvalue->lt($rvalue);

# 0

ne

ne(any $arg) (boolean)

The ne method performs a "not-equal-to" operation using the argument provided.

Since 0.08

ne example 1
package main;

use Venus::Array;
use Venus::Undef;

my $lvalue = Venus::Undef->new;
my $rvalue = Venus::Array->new;

my $result = $lvalue->ne($rvalue);

# 1
ne example 2
package main;

use Venus::Code;
use Venus::Undef;

my $lvalue = Venus::Undef->new;
my $rvalue = Venus::Code->new;

my $result = $lvalue->ne($rvalue);

# 1
ne example 3
package main;

use Venus::Float;
use Venus::Undef;

my $lvalue = Venus::Undef->new;
my $rvalue = Venus::Float->new;

my $result = $lvalue->ne($rvalue);

# 0
ne example 4
package main;

use Venus::Hash;
use Venus::Undef;

my $lvalue = Venus::Undef->new;
my $rvalue = Venus::Hash->new;

my $result = $lvalue->ne($rvalue);

# 1
ne example 5
package main;

use Venus::Number;
use Venus::Undef;

my $lvalue = Venus::Undef->new;
my $rvalue = Venus::Number->new;

my $result = $lvalue->ne($rvalue);

# 0
ne example 6
package main;

use Venus::Regexp;
use Venus::Undef;

my $lvalue = Venus::Undef->new;
my $rvalue = Venus::Regexp->new;

my $result = $lvalue->ne($rvalue);

# 1
ne example 7
package main;

use Venus::Scalar;
use Venus::Undef;

my $lvalue = Venus::Undef->new;
my $rvalue = Venus::Scalar->new;

my $result = $lvalue->ne($rvalue);

# 1
ne example 8
package main;

use Venus::String;
use Venus::Undef;

my $lvalue = Venus::Undef->new;
my $rvalue = Venus::String->new;

my $result = $lvalue->ne($rvalue);

# 0
ne example 9
package main;

use Venus::Undef;

my $lvalue = Venus::Undef->new;
my $rvalue = Venus::Undef->new;

my $result = $lvalue->ne($rvalue);

# 0

numified

numified() (number)

The numified method returns the numerical representation of the object. For undef objects this method returns 0.

Since 0.08

numified example 1
# given: synopsis;

my $numified = $undef->numified;

# 0

stringified

stringified() (string)

The stringified method always method returns ''.

Since 0.08

stringified example 1
# given: synopsis;

my $stringified = $undef->stringified;

# ""

tv

tv(any $arg) (boolean)

The tv method performs a "type-and-value-equal-to" operation using argument provided.

Since 0.08

tv example 1
package main;

use Venus::Array;
use Venus::Undef;

my $lvalue = Venus::Undef->new;
my $rvalue = Venus::Array->new;

my $result = $lvalue->tv($rvalue);

# 0
tv example 2
package main;

use Venus::Code;
use Venus::Undef;

my $lvalue = Venus::Undef->new;
my $rvalue = Venus::Code->new;

my $result = $lvalue->tv($rvalue);

# 0
tv example 3
package main;

use Venus::Float;
use Venus::Undef;

my $lvalue = Venus::Undef->new;
my $rvalue = Venus::Float->new;

my $result = $lvalue->tv($rvalue);

# 0
tv example 4
package main;

use Venus::Hash;
use Venus::Undef;

my $lvalue = Venus::Undef->new;
my $rvalue = Venus::Hash->new;

my $result = $lvalue->tv($rvalue);

# 0
tv example 5
package main;

use Venus::Number;
use Venus::Undef;

my $lvalue = Venus::Undef->new;
my $rvalue = Venus::Number->new;

my $result = $lvalue->tv($rvalue);

# 0
tv example 6
package main;

use Venus::Regexp;
use Venus::Undef;

my $lvalue = Venus::Undef->new;
my $rvalue = Venus::Regexp->new;

my $result = $lvalue->tv($rvalue);

# 0
tv example 7
package main;

use Venus::Scalar;
use Venus::Undef;

my $lvalue = Venus::Undef->new;
my $rvalue = Venus::Scalar->new;

my $result = $lvalue->tv($rvalue);

# 0
tv example 8
package main;

use Venus::String;
use Venus::Undef;

my $lvalue = Venus::Undef->new;
my $rvalue = Venus::String->new;

my $result = $lvalue->tv($rvalue);

# 0
tv example 9
package main;

use Venus::Undef;

my $lvalue = Venus::Undef->new;
my $rvalue = Venus::Undef->new;

my $result = $lvalue->tv($rvalue);

# 1

AUTHORS

Awncorp, awncorp@cpan.org

LICENSE

Copyright (C) 2000, Awncorp, awncorp@cpan.org.

This program is free software, you can redistribute it and/or modify it under the terms of the Apache license version 2.0.