Data::Functions

Treat Hashes, Arrays, Sets and Objects as Functions

Synopsis

  require 'data/functions/hash'

  number_names = { 1 => "One", 2 => "Two", 3 => "Three" }
  [1, 2, 3, 4].map(&number_names) # => ["One", "Two", "Three", nil]

  require 'data/functions/array'

  alpha = ('a'..'z').to_a
  [1, 2, 3, 4].map(&alpha) # => ["b", "c", "d", "e"]

  require 'data/functions/set'

  favorite_numbers = Set[3, Math::PI]
  [1, 2, 3, 4].select(&favorite_numbers) # => [3]

  require 'data/functions/object'

  # service objects
  class GetDataFromSomeService
    def call(user)
      # do the dirt
    end
  end

  data_for_user = GetDataFromSomeService.new
  User.all.map(&data_for_user)

require 'data/functions/hash' # loads hash patch
require 'data/functions/array' # loads array patch
require 'data/functions/set' # loads set patch
require 'data/functions/object' # loads object patch
require 'data/functions' # loads all patches

Why?

A function is a mapping of one value to another with the additional constraint that for the one input value you will always get the same output value. So, conceptually, Ruby Hashes, Arrays, Sets, and Objects (when treated immutably) are all functions. Why not treat them as such?

Installation

Add this line to your application's Gemfile:

gem 'data-functions'

And then execute:

> bundle

Or install it yourself as:

> gem install data-functions

See Also

• Clojure
• Arc

License

The gem is available as open source under the terms of the MIT License.