extensional: Class extent collector

Git: http://github.com/caruby/extensional
Author: OHSU Knight Cancer Institute
Copyright: 2010
License: MIT License
Latest Version: 1.3.1
Release Date: September 30th 2010

Synopsis

The extensional gem adds the ability of a Class to collect its instances. An extensional class is an Enumerable whose each method iterates over its instances. An optional callback block enables associative access to instances by key.

Feature List

Add instances to a Class extent.
Associative access by a designated key.
Custom unit definition.
Measurement parser.

Installing

To install the extensional gem, use the following command:

$ gem install extensional

(Add sudo if you're installing under a POSIX system as root)

Alternatively, if you've checked the source out directly, you can call rake install from the root project directory.

Usage

An extensional class is an Enumerable whose each method iterates over its instances, e.g.:

class Person
  make_extensional
end
Employee.new(20195) #=> Employee@2653
Employee.to_a #=> [Employee@2653]

An optional callback block adds associative access to instances by key using the class for method, e.g.:

class Employee
  make_extensional { |hash, emp| hash[emp.number] = emp }
  ...
end
Employee.for(20196) #=> nil
Employee.new(20196) #=> Employee@2654
Employee.for(20196) #=> Employee@2654

The Class.make_extensional RDoc includes additional examples.

Changelog

September.30.10: 2010.1 release
- Initial public release