This repository contains code snippets used in my presentation on Ruby's enumerable module. Ruby code was written to run on Ruby 2.2.
Enumerable presentation on Slidedeck
To run a sample, clone the repo and install the gems:
$ git clone https://github.com/rossta/loves-enumerable.git
$ cd loves-enumerable
$ bundle installThen simply run the code with the ruby executable.
$ ruby code/pascals_triangle.rbYou'll get the most out of this repo by inspecting the source along with following the presentation.
Use more of the Enumerable API
- look for more direct solutions
- read the docs
Learn how Enumerable methods are implemented
- it’s not magic
- implement Enumerable on your own
- create your own extensions
Encapsulate complexity of enumerating
- e.g. stream data to client,
- deferred data fetching
Provide Enumerators
- for any method that returns an enumerable with a block: return an enumerator when the block is missing
When to be Lazy
- for avoiding eager evaluation
- for filtering results over large collection
Embrace the functional flavor
- given the same inputs, you can expect the same results
- use Enumerables like Legos: as building blocks
Many of the ideas and examples are adapted from other great sources. Please check out the following to learn more.
- https://practicingruby.com/articles/building-enumerable-and-enumerator
- http://www.sitepoint.com/guide-ruby-collections-iii-enumerable-enumerator/
- http://jwb.io/20130114-building-sequences-with-enumerator.html
- https://speakerdeck.com/jeg2/10-things-you-didnt-know-ruby-could-do
- http://dgiim.github.io/blog/2015/08/24/ruby-enumerators/
- http://patshaughnessy.net/2013/4/3/ruby-2-0-works-hard-so-you-can-be-lazy
- http://railsware.com/blog/2012/03/13/ruby-2-0-enumerablelazy/
- http://blog.honeybadger.io/using-lazy-enumerators-to-work-with-large-files-in-ruby/
- https://gist.github.com/barmstrong/1323865 # processing large csv
- http://www.sitepoint.com/implementing-lazy-enumerables-in-ruby/
- http://old.blog.phusion.nl/2014/08/03/why-rails-4-live-streaming-is-a-big-deal
- http://www.sitepoint.com/streaming-with-rails-4/
- http://smsohan.com/blog/2013/05/09/genereating-and-streaming-potentially-large-csv-files-using-ruby-on-rails
- https://github.com/rubinius/rubinius/blob/master/kernel/common/enumerable.rb
- https://github.com/rubinius/rubinius/blob/master/kernel/common/enumerator.rb
- https://github.com/sferik/twitter/blob/master/lib/twitter/enumerable.rb
- https://github.com/bbatsov/powerpack/tree/master/lib/powerpack/enumerable
- https://github.com/rubyworks/facets
- The Well-Grounded Rubyist by David Black