Enumerable Attributes

Enumerable Attributes gives you all the sexiness of the Enumerable module on arbitrary attribute collections with one extra line compared to Enumerable

Current Status

EnumerableAttributes is an idea I had while reading Smalltalk Best Practice Patterns by Kent Beck and felt crazy enough to implement on a Tuesday over lunch.

By the weekend of October 21 - 22, 2011 I should have this published on Rubygems.

Installation

Enumerable Attributes will be packaged as a gem. Either gem install enumerable_attributes from the command line or gem 'enumerable_attributes' within your Gemfile`

Example

require 'enumerable_attributes'

class Document
    include EnumerableAttributes
    attr_enumerable :words, :lines, :pages

    def initialize title, authors, text
        @authors = authors
        process_text # defines you @words, @lines, @pages
    end
end

doc = Document.new "Cool Story", ["Bro"], "So some stuff happened
and then I found $20!"

doc.words_size #=> 9
doc.map_words{ |w| w.upcase } #=> "SO SOME STUFF HAPPENED AND THEN I FOUND $20!"
doc.includes_word? "brah" #=> false

Justification

In order to expose these collections currently there are two ways to go:

1. Make each collection accessible through attr_reader.
2. Write #each_word, #each_line, and #each_page methods.

In the first case, you're left with the unsatisfying feeling of having exposed your implementation to the outside when you call document.words.each {|w| ...}

In the second, you're stuck with the each method when ruby gives us such wonderful methods as #find, #collect, #select, and #reject and many others.

Wouldn't it be great if you could create enumerable attributes declaratively the same way you create regular readers and writers. With Ruby's metaprogramming and flexibility and my bravado getting there should be a cinch!