monadic.rb

require 'rubygems'
require 'monadic'

class MonadicService
  def initialize(user_id)
    @user_id = user_id
  end

  def call
    response = HTTParty.get("https://jsonplaceholder.typicode.com/users/#{@user_id}")
    if response.code == 200
      Success(response.body)
    else
      Failure("Error status #{response.code}")
    end
  end
end

# goal: print the outcome for:
# - one single call
# - two calls in a row

Success({})
  .bind { MonadicService.new(42).call) }
  .bind {|result| puts(result); true  }   # last true  statement feels lame
  .or   {|error|  puts(error);  false }   # last false statement feels lame


Success({})
  .bind {|hash| MonadicService.new(12).call.bind  {|r| hash.merge({ value1: r })}}
  .bind {|hash| MonadicService.new(14).call.bind  {|r| hash.merge({ value2: r })}}
  .bind {|hash|  puts(hash[:value1], hash[:value2]); true }
  .or   {|error| puts(error); false }