Maybelline

An implementation of the maybe monad.

Setup

Gemfile

gem 'maybelline'

Manual

require 'maybelline'

Usage

Say you have some objects like the ones below:

require 'ostruct'

data = {
  "neat" => {
    "super" => "cool",
    "lame"  => nil
  }
}

object = OpenStruct.new(data)
object.neat = OpenStruct.new(object.neat)

If any method in the chain of calls returns nil, the block will return nil.

Maybe(data){|d| d["this_key_doesnt_exist"]["this_key_wont_get_called"]} #=> nil
data.maybe{|d| d["this_key_doesnt_exist"]["this_key_wont_get_called"]}  #=> nil
object.maybe{|o| o.neat.lame.this_method_never_gets_called}             #=> nil

If it is successful, it will return the value.

data.maybe{|d| d["neat"]["super"]}  #=> "cool"
object.maybe{|o| o.neat.super}      #=> "cool"

Note on Reporting Issues

• Try to make a failing test case
• Tell me which version of ruby you're using
• Tell me which OS you are using
• Provide me with any extra files if necessary

Note on Patches/Pull Requests

• Fork the project.
• Make your feature addition or bug fix.
• Add tests for it. This is important so I don't break it in a future version unintentionally.
• Commit, do not mess with rakefile, version, or history. (if you want to have your own version, that is fine but bump version in a commit by itself I can ignore when I pull)
• Send me a pull request. Bonus points for topic branches.