• NAME
• ABSTRACT
• SYNOPSIS
• DESCRIPTION
• INHERITS
• METHODS
  • cast
  • default
  • eq
  • ge
  • gele
  • gt
  • gtlt
  • le
  • lt
  • ne
  • numified
  • stringified
  • tv
• AUTHORS
• LICENSE

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.

cpanm Venus

perl -MCPAN -e shell
install Venus