Free classes software for linux

Class::Generate is a Perl module that can generate Perl class hierarchies.

SYNOPSIS

use Class::Generate qw(class subclass delete_class);

# Declare class Class_Name, with the following types of members:
class
Class_Name => [
s => $, # scalar
a => @, # array
h => %, # hash
c => Class, # Class
c_a => @Class, # array of Class
c_h => %Class, # hash of Class
&m => body, # method
];

# Allocate an instance of class_name, with members initialized to the
# given values (pass arrays and hashes using references).
$obj = Class_Name->new ( s => scalar,
a => [ values ],
h => { key1 => v1, ... },
c => Class->new,
c_a => [ Class->new, ... ],
c_h => [ key1 => Class->new, ... ] );

# Scalar type accessor:
$obj->s($value); # Assign $value to member s.
$member_value = $obj->s; # Access members value.

# (Class) Array type accessor:
$obj->a([value1, value2, ...]); # Assign whole array to member.
$obj->a(2, $value); # Assign $value to array member 2.
$obj->add_a($value); # Append $value to end of array.
@a = $obj->a; # Access whole array.
$ary_member_value = $obj->a(2); # Access array member 2.
$s = $obj->a_size; # Return size of array.
$value = $obj->last_a; # Return last element of array.

# (Class) Hash type accessor:
$obj->h({ k_1=>v1, ..., k_n=>v_n }) # Assign whole hash to member.
$obj->h($key, $value); # Assign $value to hash member $key.
%hash = $obj->h; # Access whole hash.
$hash_member_value = $obj->h($key); # Access hash member value $key.
$obj->delete_h($key); # Delete slot occupied by $key.
@keys = $obj->h_keys; # Access keys of member h.
@values = $obj->h_values; # Access values of member h.

$another = $obj->copy; # Copy an object.
if ( $obj->equals($another) ) { ... } # Test equality.

subclass s => [ ], -parent => class_name;

The Class::Generate package exports functions that take as arguments a class specification and create from these specifications a Perl 5 class. The specification language allows many object-oriented constructs: typed members, inheritance, private members, required members, default values, object methods, class methods, class variables, and more.

CPAN contains similar packages. Why another? Because object-oriented programming, especially in a dynamic language like Perl, is a complicated endeavor. I wanted a package that would work very hard to catch the errors you (well, I anyway) commonly make. I wanted a package that could help me enforce the contract of object-oriented programming. I also wanted it to get out of my way when I asked.

Class::Bits is a Perl module with class wrappers around bit vectors.

SYNOPSIS

package MyClass;
use Class::Bits;

make_bits( a => 4, # 0..15
b => 1, # 0..1
c => 1, # 0..1
d => 2, # 0..3
e => s4 # -8..7
f => s1 # -1..0
);

package;

$o=MyClass->new(a=>12, d=>2);
print "o->b is ", $o->b, "n";

print "bit vector is ", unpack("h*", $$o), "n";

$o2=$o->new();
$o3=MyClass->new($string);

ABSTRACT

Class::Bits creates class wrappers around bit vectors.

Class::Bits defines classes using bit vectors as storage.
Object attributes are stored in bit fields inside the bit vector. Bit field sizes have to be powers of 2 (1, 2, 4, 8, 16 or 32).

There is a class constructor subroutine:

make_bits( field1 => size1, field2 => size2, ...)

exports in the calling package a ctor, accessor methods, some utility methods and some constants:

Sizes can be prefixed by s or u to define signedness of the field. Default is unsigned.

$class->new()

creates a new object with all zeros.

$class->new($bitvector)

creates a new object over $bitvector.

$class->new(%fields)

creates a new object and initializes its fields with the values in %fields.

$obj->new()

clones an object.

$obj->$field()
$obj->$field($value)

gets or sets the value of the bit field $field inside the bit vector.

$class->length
$obj->lenght

returns the size in bits of the bit vector used for storage.

$class->keys
$obj->keys

returns an array with the names of the object attributes

$obj->as_hash

returns a flatten hash with the object attributes, i.e.:
my %values=$obj->as_hash;

%INDEX

hash with offsets as used by vec perl operator (to get an offset in bits, the value has to be multiplied by the corresponding bit field size).

%SIZES

hash with bit field sizes in bits.

%SIGNED

hash with signedness of the fields

Bit fields are packed in the bit vector in the order specified as arguments to make_bits.

Bit fields are padded inside the bit vector, i.e. a class created like

make_bits(A=>1, B=>2, C=>1, D=>4, E=>8, F=>16);

will have the layout

AxBBCxxx DDDDxxxx EEEEEEEE xxxxxxxx FFFFFFFF FFFFFFFF

Class::Classless is a Perl framework for classless OOP.

SYNOPSIS

use strict;
use Class::Classless;
my $ob1 = $Class::Classless::ROOT->clone;
$ob1->{NAME} = Ob1;
$ob1->{stuff} = 123;
$ob1->{Thing} = 789;

my $ob2 = $ob1->clone;
$ob2->{NAME} = Ob2;

printf "ob1 stuff: n", $ob1->{stuff};
printf "ob2 stuff: n", $ob2->{stuff};
printf "ob1 Thing: n", $ob1->{Thing};
printf "ob2 Thing: n", $ob2->{Thing};

$ob1->{METHODS}{zaz} = sub {
print "Zaz! on ", $_[0]{NAME}, "n";
};

$ob1->zaz;
$ob2->zaz;
$ob1->EXAMINE;
$ob2->EXAMINE;
This prints the following:
ob1 stuff: < 123 >
ob2 stuff: < 123 >
ob1 Thing: < 789 >
ob2 Thing: < >
Zaz! on Ob1
Zaz! on Ob2
< Class::Classless::X=HASH(0x200236f4) >
stuff, 123,
NAME, Ob1,
Thing, 789,
METHODS, { zaz, CODE(0x20068360) },
PARENTS, [ ROOT ],
< Class::Classless::X=HASH(0x2002cb48) >
stuff, 123,
NAME, Ob2,
METHODS, { },
PARENTS, [ Ob1 ],

In class-based OOP frameworks, methods are applicable to objects by virtue of objects belonging to classes that either provide those methods, or inherit them from classes that do.

In classless OOP frameworks (AKA delegation-and-prototypes frameworks), what methods an object is capable of is basically an attribute of that object. That is, in Perl terms: instead of methods being entries in the symbol table of the package/class the object belongs to, they are entries in a hash table inside the object. Inheritance is implemented not by having classes inheriting from other classes (via ISA lists), but by having objects inherit from other objects (via PARENTS lists).

In class-based OOP frameworks, you get new objects by calling constructors. In a classless framework, you get new objects by copying ("cloning") an existing object -- and the new clone becomes a child (inheritor) of the original object. (Where do you get the one original object? The language provides one, which has no parents, and which contains some general purpose methods like "clone".)

Class::Struct::FIELDS module combine Class::Struct, base and fields.

SYNOPSIS

(This page documents Class::Struct::FIELDS v.1.1.)
use Class::Struct::FIELDS;
# declare struct, based on fields, explicit class name:
struct (CLASS_NAME => { ELEMENT_NAME => ELEMENT_TYPE, ... });

use Class::Struct::FIELDS;
# declare struct, based on fields, explicit class name
# with inheritance:
struct (CLASS_NAME => [qw(BASE_CLASSES ...)],
{ ELEMENT_NAME => ELEMENT_TYPE, ... });

package CLASS_NAME;
use Class::Struct::FIELDS;
# declare struct, based on fields, implicit class name:
struct (ELEMENT_NAME => ELEMENT_TYPE, ...);

package CLASS_NAME;
use Class::Struct::FIELDS;
# declare struct, based on fields, implicit class name
# with inheritance:
struct ([qw(BASE_CLASSES ...)], ELEMENT_NAME => ELEMENT_TYPE, ...);

package MyObj;
use Class::Struct::FIELDS;
# declare struct with four types of elements:
struct (s => $, a => @, h => %, x => &, c => My_Other_Class);

$obj = new MyObj; # constructor

# scalar type accessor:
$element_value = $obj->s; # element value
$obj->s (new value); # assign to element

# array type accessor:
$ary_ref = $obj->a; # reference to whole array
$ary_element_value = $obj->a->[2]; # array element value
$ary_element_value = $obj->a (2); # same thing
$obj->a->[2] = new value; # assign to array element
$obj->a (2, newer value); # same thing

# hash type accessor:
$hash_ref = $obj->h; # reference to whole hash
$hash_element_value = $obj->h->{x}; # hash element value
$hash_element_value = $obj->h (x); # same thing
$obj->h->{x} = new value; # assign to hash element
$obj->h (x, newer value); # same thing

# code type accessor:
$code_ref = $obj->x; # reference to code
$obj->x->(...); # call code
$obj->x (sub {...}); # assign to element

# regexp type accessor:
$regexp = $obj->r; # reference to code
$string =~ m/$obj->r/; # match regexp
$obj->r (qr/ ... /); # assign to element

# class type accessor:
$element_value = $obj->c; # object reference
$obj->c->method (...); # call method of object
$obj->c (My_Other_Class::->new); # assign a new object

Class::Struct::FIELDS exports a single function, struct. Given a list of element names and types, and optionally a class name and/or an array reference of base classes, struct creates a Perl 5 class that implements a "struct-like" data structure with inheritance.

The new class is given a constructor method, new, for creating struct objects.
Each element in the struct data has an accessor method, which is used to assign to the element and to fetch its value. The default accessor can be overridden by declaring a sub of the same name in the package. (See Example 2.)

Each elements type can be scalar, array, hash, code or class.

Class::Multimethods::Pure is a Perl module that contains a method-ordered multimethod dispatch.

SYNOPSIS

use Class::Multimethods::Pure;

package A;
sub magic { rand() > 0.5 }
package B;
use base A;
package C;
use base A;

BEGIN {
multi foo => (A, A) => sub {
"Generic catch-all";
};

multi foo => (A, B) => sub {
"More specific";
};

multi foo => (subtype(A, sub { $_[0]->magic }), A) => sub {
"This gets called half the time instead of catch-all";
};

multi foo => (any(B, C), A) => sub {
"Accepts B or C as the first argument, but not A"
};
}

Class::Declare is a Perl module created to declare classes with public, private and protected attributes and methods.

SYNOPSIS

package My::Class;

use strict;
use warnings;
use base qw( Class::Declare );

__PACKAGE__->declare(

public => { public_attr => 42 } ,
private => { private_attr => Foo } ,
protected => { protected_attr => Bar } ,
class => { class_attr => [ 3.141 ] }
static => { static_attr => { a => 1 } } ,
restricted => { restricted_attr => string } ,
abstract => abstract_attr ,
friends => main::trustedsub ,
new => [ public_attr , private_attr ] ,
init => sub { # object initialisation
...
1;
} ,
strict => 0

);

sub publicmethod {
my $self = __PACKAGE__->public( shift );
...
}

sub privatemethod {
my $self = __PACKAGE__->private( shift );
...
}

sub protectedmethod {
my $self = __PACKAGE__->protected( shift );
...
}

sub classmethod {
my $self = __PACKAGE__->class( shift );
...
}

sub staticmethod {
my $self = __PACKAGE__->static( shift );
...
}

sub restrictedmethod {
my $self = __PACKAGE__->restricted( shift );
...
}

sub abstractmethod { __PACKAGE__->abstract }

1;

...

my $obj = My::Class->new( public_attr => fish );

MOTIVATION

One of Perls greatest strengths is its flexible object model. You can turn anything (so long as its a reference, or you can get a reference to it) into an object. This allows coders to choose the most appropriate implementation for each specific need, and still maintain a consistent object oriented approach.
A common paradigm for implementing objects in Perl is to use a blessed hash reference, where the keys of the hash represent attributes of the class. This approach is simple, relatively quick, and trivial to extend, but its not very secure. Since we return a reference to the hash directly to the user they can alter hash values without using the classs accessor methods. This allows for coding "short-cuts" which at best reduce the maintainability of the code, and at worst may introduce bugs and inconsistencies not anticipated by the original module author.

On some systems, this may not be too much of a problem. If the developer base is small, then we can trust the users of our modules to Do The Right Thing. However, as a modules user base increases, or the complexity of the systems our modules are embedded in grows, it may become desirable to control what users can and cant access in our module to guarantee our codes behaviour. A traditional method of indicating that an objects data and methods are for internal use only is to prefix attribute and method names with underscores. However, this still relies on the end user Doing The Right Thing.

Class::Declare provides mechanisms for module developers to explicitly state where and how their class attributes and methods may be accessed, as well as hiding the underlying data store of the objects to prevent unwanted tampering with the data of the objects and classes. This provides a robust framework for developing Perl modules consistent with more strongly-typed object oriented languages, such as Java and C++, where classes provide public, private, and protected interfaces to object and class data and methods.

Class::Spiffy is a Spiffy Framework with No Source Filtering.

SYNOPSIS

package Keen;
use strict;
use warnings;
use Class::Spiffy -base;
field mirth;
const mood => :-);

sub happy {
my $self = shift;
if ($self->mood eq :-() {
$self->mirth(-1);
print "Cheer up!";
}
super;
}

1;

"Class::Spiffy" is a framework and methodology for doing object oriented (OO) programming in Perl. Class::Spiffy combines the best parts of Exporter.pm, base.pm, mixin.pm and SUPER.pm into one magic foundation class. It attempts to fix all the nits and warts of traditional Perl OO, in a clean, straightforward and (perhaps someday) standard way.

Class::Spiffy borrows ideas from other OO languages like Python, Ruby, Java and Perl 6. It also adds a few tricks of its own.

If you take a look on CPAN, there are a ton of OO related modules. When starting a new project, you need to pick the set of modules that makes most sense, and then you need to use those modules in each of your classes. Class::Spiffy, on the other hand, has everything youll probably need in one module, and you only need to use it once in one of your classes. If you make Class::Spiffy the base class of the basest class in your project, Class::Spiffy will automatically pass all of its magic to all of your subclasses. You may eventually forget that youre even using it!

The most striking difference between Class::Spiffy and other Perl object oriented base classes, is that it has the ability to export things. If you create a subclass of Class::Spiffy, all the things that Class::Spiffy exports will automatically be exported by your subclass, in addition to any more things that you want to export. And if someone creates a subclass of your subclass, all of those things will be exported automatically, and so on. Think of it as "Inherited Exportation", and it uses the familiar Exporter.pm specification syntax.
To use Class::Spiffy or any subclass of Class::Spiffy as a base class of your class, you specify the -base argument to the use command.

use MySpiffyBaseModule -base;

You can also use the traditional use base MySpiffyBaseModule; syntax and everything will work exactly the same. The only caveat is that Class::Spiffy must already be loaded. Thats because Class::Spiffy rewires base.pm on the fly to do all the Spiffy magics.

Class::Spiffy has support for Ruby-like mixins with Perl6-like roles. Just like base you can use either of the following invocations:

use mixin MySpiffyBaseModule;
use MySpiffyBaseModule -mixin;

The second version will only work if the class being mixed in is a subclass of Class::Spiffy. The first version will work in all cases, as long as Class::Spiffy has already been loaded.

To limit the methods that get mixed in, use roles. (Hint: they work just like an Exporter list):

use MySpiffyBaseModule -mixin => qw(:basics x y !foo);

A useful feature of Class::Spiffy is that it exports two functions: field and const that can be used to declare the attributes of your class, and automatically generate accessor methods for them. The only difference between the two functions is that const attributes can not be modified; thus the accessor is much faster.

One interesting aspect of OO programming is when a method calls the same method from a parent class. This is generally known as calling a super method. Perls facility for doing this is butt ugly:

sub cleanup {
my $self = shift;
$self->scrub;
$self->SUPER::cleanup(@_);
}

Class::Spiffy makes it, er, super easy to call super methods. You just use the super function. You dont need to pass it any arguments because it automatically passes them on for you. Heres the same function with Class::Spiffy:

sub cleanup {
my $self = shift;
$self->scrub;
super;
}

Class::Spiffy has a special method for parsing arguments called parse_arguments, that it also uses for parsing its own arguments. You declare which arguments are boolean (singletons) and which ones are paired, with two special methods called boolean_arguments and paired_arguments. Parse arguments pulls out the booleans and pairs and returns them in an anonymous hash, followed by a list of the unmatched arguments.

Finally, Class::Spiffy can export a few debugging functions WWW, XXX, YYY and ZZZ. Each of them produces a YAML dump of its arguments. WWW warns the output, XXX dies with the output, YYY prints the output, and ZZZ confesses the output. If YAML doesnt suit your needs, you can switch all the dumps to Data::Dumper format with the - dumper option.