The document discusses object-oriented programming (OOP) in Perl 6, highlighting concepts such as classes, inheritance, roles, and delegation. It compares Perl 5 and Perl 6 implementations, illustrating the syntax for defining attributes, methods, and using roles for reusable functionality. Additionally, it touches on introspection and metaobject protocols as critical components of OOP in Perl 6.

1. Perl 6 OOP

2. What is OOP ?

3. Larry Wall Says:

4. What is OOP ?

5. Position

6. Out Of Position

7. OOP

8. Man With Clue

9. Read That !

10. Damian Says:
Object-oriented
programming ...
many opinions,
theories, and even
ideologies have
been formulated on
the subject. ... Most
are mutually
inconsistent.

11. OOP
Classes / Prototypes
(Multiple) Inheritance / Roles
MMD + Delegation
Types + Subtypes
Introspection / Metaobj.

12. His Opinion

13. TIMTOWTDI

14. All There in Beauty

15. In Search Of Perf.

16. Starts With A Class

17. Class
class

18. Class
class
instanceable name space

19. Class
class module package

20. Class
class Excalibur;
class Babylon;

21. Class
class
instanceable name space

22. NS in Braces
class Excalibur {
...
}

23. Object

24. Object
my $obj =
Class.new();

25. Ops Changed
my $obj =
Class.new();

26. Create New

27. Clone Existing

28. Object
my $obj =
$old.clone();

29. Object
my $obj =
$old.clone(...);

30. Positional Paramters
clone($pos1, $pos2);

31. Named Parameters
clone( :key('value'),);

32. With Autoquoting
clone( :key<value>,);

33. Old School Works Too
clone( key=>'value',);

34. Object
new & clone
bless stayed

35. Attributes
+
Methods

36. Space Ship

37. Class
class Spaceship {
has Int $.speed;
method stop {
$speed = 0
}
}

38. I can do that too !

39. In Perl 5
package Spaceship;
use Moose;
has 'speed' => (
is => 'ro';
isa => 'Int';
);
sub stop {
$self = shift;
$self->speed = 0;
}

40. Me too !

41. In Perl 5
package Spaceship;
use Moo;
has 'speed' => (
is => 'ro';
isa => sub { die "…"
unless looks_like_number($_[0]);
});
sub stop {
$self = shift;
$self->speed = 0;
}

42. In Perl 5
use MooseX::Declare;
class Spaceship {
has 'speed' => (
is => 'ro';
isa => 'Int';
);
method stop {
$self->speed = 0;
}
}

43. Class
class Spaceship {
has Int $.speed;
method stop {
$.speed = 0;
}
}

44. Attribute Usage
P5
$self->speed
shift->speed
P6
$.speed
self.speed
$!speed

45. Twigil of
Accessors
.
!
public
private

46. Twigil of
Accessors
.
!
public
private
has $!speed; # private

47. Twigil of
Accessors
.
!
has $speed;
public
private
# private too

48. trusts

49. trusts
class Dog {
trusts Cat;
has $!Bone;
}

50. trusts
class Cat {
method steal {
my $carlo = Dog.new();
$carlo!Bone = 0;
...

51. .
!
^
:
*
?
=
~
Twigils
punlic access.
private access.
pos. auto para.
named auto p.
global var
compiler info
POD
sublang

52. Sigils
$
@
%
Scalar
Array
Hash

53. Sigils
has $.speed;
has @.shuttle;
has %.crew;

54. In Perl 5
use MooseX::Declare;
class Spaceship {
has 'speed' => (
is => 'ro';
isa => 'Int';
);
method stop {
$self->speed = 0;
}
}

55. In Perl 5
use MooseX::Declare;
class Spaceship {
has 'speed' => (
is => 'rw';
isa => 'Int';
);
method stop {
$self->speed = 0;
}
}

56. Class
class Spaceship {
has Int $.speed is rw;
}
method stop {
$.speed = 0;
}

57. Class
class Spaceship {
has Int $.speed is rw = 0;
}
method stop {
$.speed = 0;
}

58. In Perl 5
use MooseX::Declare;
class Spaceship {
has 'speed' => (
is => 'rw';
isa => 'Int';
default => 0;
);
method stop {
$self->speed = 0;
}
}

59. Perl 6 Attribute
no:
isa default (just Syntax)
predicate required coerce
reader writer init_arg
clearer builder lazy_build

60. That was my idea!

61. Perl 6 & Moose
has is

62. Subtypes

63. Moose
subtype 'Slogan'
=> as 'Str'
=> where {length $_< 50};

64. Perl 6
my subset Slogan of Str
where {$_.chars < 50};

65. Delegation

66. Excalibur

67. Perl 6
class Excalibur;
has $.clock handles 'now';
$excalibur = Excalibur.new;
$excalibur.clock.now;

68. Perl 6
class Excalibur;
has DateTime $.clock
handles 'now';
$excalibur = Excalibur.new;
$excalibur.now;

69. Moose
has 'clock' => (
handles => 'now';
);

70. Moose Rename
has 'clock' => (
handles => {
now => 'time'
};
);

71. Perl 6 Rename
class Spaceship;
has DateTime $.clock
handles { :time<now>};

72. Methods

73. Methods
method stop { … }

74. Methods
method !stop { … }

75. Methods
method !stop { … }
submethod

76. Methods
method !stop { … }
submethod # !inherit

77. MMD
?

78. MMD
Multi
Method
Dispatch

79. MMD
only
multi
proto

80. MMD
only # default anyway
multi # look at !
proto # later

81. MMD
multi method navigate
(Coord $place) {}
multi method navigate
(Str $cmd) {};

82. MMD
$excalibur.navigate('back');

83. MMD
only # default anyway
multi # MMD
proto # own handling

84. Inheritance

85. MooseX::Declare
class WhiteStar
extends Spaceship;

86. Inheritance
extends => is

87. Perl 6
class WhiteStar
is Spaceship;

88. Multiple Inheritance
class WhiteStar
is Spaceship is Minbari;

89. Vererbung später
extends => also is

90. MooseX::Declare
class WhiteStar;
...
extends Spaceship;

91. Perl 6
class WhiteStar {
...
also is Spaceship;

92. Roles

93. Class Hierarchy

94. Where to insert ?

95. Solution
Role:
Unit Of Reusable
Functionality

96. Therefore
Role:
Unit Of Reusable
Functionality
Outside Any Hierarchy

97. Solution
Role:
Unit Of Reusable
Functionality
Trait Elsewhere

98. Therefore
Role:
Unit Of Reusable
Functionality
Roles have Atributes, Traits not

99. Therefore
Role:
Reusable => Small

100. Remember?
Role:
Reusable => Small
Class:
instanceable name space

101. How To Solve That
Role:
Reusable => Small
Class:
Complete => Big

102. Class Do Can't Both
Role:
Reusable => Small
!=
Class:
Complete => Big

103. Roles
may be inherited !
if mixed into a class
& remove @ run time

104. Roles
conflicts throw exceptions

105. Roles
conflicts throw exceptions
No global overwrite like
Ruby Mixins

106. Roles
conflicts throw exceptions
No global overwrite like
Ruby Mixins
Refinements doesn't solve it all

107. Roles
conflicts throw exceptions
Roles > multiple inheritance
(conflicts remain unhandled
- in intelligent way)

108. Roles
conflicts throw exceptions
except when method is empty

109. Roles
conflicts throw exceptions
except when method is empty
then is has to be overwritten
(interface)

110. Roles
role Spaceship {
has Int $.speed;
method stop {
$.speed = 0
}
}

111. Roles
role Clock {
has DateTime $.time;
method alarm {
...
}
}

112. Apply Roles
with => does

113. Moose
class Excalibur
extends WhiteStar
with Clock;

114. Moo too !

115. Moo::Role
package Excalibur;
extends 'WhiteStar';
with 'Clock';

116. Perl 6
class Excalibur
is WhiteStar
does Clock;

117. Perl 6
class Excalibur
is Whitestar;
also does Clock;

118. Perl 6
class Excalibbur
is WhiteStar;
also does Clock
does PlasmaGun;

119. Perl 6
$excalibur does Clock;

120. Introspection

121. Methods
WHAT short name
WHICH object ID (type)
WHO package, long name in str context
WHERE memory address
HOW
object of meta class
WHEN (reserved for events?)
WHY
(reserved for documentation)
WHENCE autovivification of closures

122. Methods
WHAT short name
WHICH object ID (type)
WHO package, long name in str context
WHERE memory address
HOW
object of meta class
WHEN (reserved for events?)
WHY
(reserved for documentation)
WHENCE autovivification of closures

123. Methods
WHAT short name
WHICH object ID (type)
WHO package, long name in str context
WHERE memory address
HOW
object of meta class
WHEN (reserved for events?)
WHY
(reserved for documentation)
WHENCE autovivification of closures

124. Introspection
Class.HOW.methods($obj)
Class.^methods()

125. Metaobjectmethods
identifier
name authority version author
description
licensed
subject
parents
language
roles

126. Deeper & Deeper
$obj.^methods()[$which].signature

127. Introspection
All is an Object

128. Introspection
All is an Object
„objects are stupid“.uc

129. Introspection
All is an Object
Commands are Methods

130. Introspection
All is an Object
Commands are Methods
(Operators too)

131. Introspection
All is an Object
Commands are Methods
(Operators too)
MMD is everywhere

132. Introspection
All is an Object
Commands are Methods
(Operators too)
MMD is everywhere
also in Regexes

133. Name Spaces
package module
class

134. A Kind Of Class
package module
class grammar

135. Grammars
grammar {
token { … }
rule { … }
regex { … }
}

136. Learn More
S12: Objekte,S14: Rollen
perl6.org/documentation
http://perlcabal.org/syn/
opt. Precise & Volume

137. Learn More
Perl 6 Docs
doc.perl6.org/language/objects
Opt.: Short & Precise

138. Learn More
Perl 6 Tablets
tablets.perl6.org
opt.: Hypertext & Volume

139. Cockaigne

140. Thank You