NAME

Chemistry::Obj - Abstract chemistry object

SYNOPSIS

    package MyObj;
    use base "Chemistry::Obj";
    Chemistry::Obj::accessor('color', 'flavor');

    package main;
    my $obj = MyObj->new(name => 'bob', color => 'red');
    $obj->attr(size => 42);
    $obj->color('blue');
    my $color = $obj->color;
    my $size = $obj->attr('size');

DESCRIPTION

This module implements some generic methods that are used by Chemistry::Mol, Chemistry::Atom, Chemistry::Bond, Chemistry::File, etc.

Common Attributes

There are some common attributes that may be found in molecules, bonds, and atoms, such as id, name, and type. They are all accessed through the methods of the same name. For example, to get the id, call "$obj->id"; to set the id, call "$obj->id('new_id')".

id

Objects should have a unique ID. The user has the responsibility for uniqueness if he assigns ids; otherwise a unique ID is assigned sequentially.

name

An arbitrary name for an object. The name doesn't need to be unique.

type

The interpretation of this attribute is not specified here, but it's typically used for bond orders and atom types.

attr

A space where the user can store any kind of information about the object. The accessor method for attr expects the attribute name as the first parameter, and (optionally) the new value as the second parameter. It can also take a hash or hashref with several attributes. Examples:

    $color = $obj->attr('color');
    $obj->attr(color => 'red');
    $obj->attr(color => 'red', flavor => 'cherry');
    $obj->attr({color => 'red', flavor => 'cherry'});

OTHER METHODS

$obj->del_attr($attr_name)

Delete an attribute.

$class->new(name => value, name => value...)

Generic object constructor. It will automatically call each "name" method with the parameter "value". For example,

    $bob = Chemistry::Obj->new(name => 'bob', attr => {size => 42});

is equivalent to

    $bob = Chemistry::Obj->new;
    $bob->name('bob');
    $bob->attr({size => 42});

OPERATOR OVERLOADING

Chemistry::Obj overloads a couple of operators for convenience.

"": The stringification operator. Stringify an object as its id. For example, If an object $obj has the id 'a1', print "$obj" will print 'a1' instead of something like 'Chemistry::Obj=HASH(0x810bbdc)'. If you really want to get the latter, you can call "overload::StrVal($obj)". See overload for details.
cmp: Compare objects by ID. This automatically overloads "eq", "ne", "lt", "le", "gt", and "ge" as well. For example, "$obj1 eq $obj2" returns true if both objects have the same id, even if they are different objects with different memory addresses. In contrast, "$obj1 == $obj2" will return true only if $obj1 and $obj2 point to the same object, with the same memory address.

SOURCE CODE REPOSITORY

<https://github.com/perlmol/Chemistry-Mol>

AUTHOR

Ivan Tubert-Brohman <itub@cpan.org>