thatrubylove

# Functional coding in Ruby - better than chunky bacon
print_to_console   = ->(msg) { puts msg }
print_to_motd_file = ->(msg) { File.write("motd.txt", msg) }

# Display the "message of the day" via the selected printer
motd  = ->(printer) {
  msg = ["Hello World,\n",
        "  Sincerely,\n",
        "  thatrubylove"].join
  printer.(msg)

thatrubylove

sum         = ->(num_list) { num_list.reduce(:+) }
square      = ->(number  ) { number * number }
squares     = ->(num_list) { num_list.map {|num| square.(num) } }
sum_squares = ->(num_list) { sum.(squares.(num_list)) }
square_sum  = ->(num_list) { square.(sum.(num_list)) }

gem 'minitest'
require 'minitest/autorun'

describe "sum_squares" do

thatrubylove

[
  {:type=>"Functional::Lists::SinglyLinked", :operation=>"#plus", :sample_size=>10000, :benchmark=>0.116519289}, 
  {:type=>"Functional::Lists::SinglyLinked", :operation=>"#plus", :sample_size=>50000, :benchmark=>0.557987583}, 
  {:type=>"Functional::Lists::SinglyLinked", :operation=>"#plus", :sample_size=>750000, :benchmark=>18.900261197}, 
  {:type=>"Functional::Lists::SinglyLinked", :operation=>"#plus", :sample_size=>2000000, :benchmark=>145.656489316}
],
[
  {:type=>"Array", :operation=>"#plus", :sample_size=>10000, :benchmark=>1.640012864}, 
  {:type=>"Array", :operation=>"#plus", :sample_size=>50000, :benchmark=>5.108800796}, 
  {:type=>"Array", :operation=>"#plus", :sample_size=>750000, :benchmark=>71.655338726}, 

thatrubylove

Rehearsal -----------------------------------------------------
array#push	 (100)   0.000000   0.000000   0.000000 (  0.000013)
list#push 	 (100)   0.000000   0.000000   0.000000 (  0.000078)
-------------------------------------------- total: 0.000000sec

                        user     system      total        real
array#push	 (100)   0.000000   0.000000   0.000000 (  0.000012)
list#push 	 (100)   0.000000   0.000000   0.000000 (  0.000044)
Rehearsal ------------------------------------------------------
array#push	 (1000)   0.000000   0.000000   0.000000 (  0.000084)

thatrubylove

Rank = Struct.new(:rank, :value) do
  def to_s; rank; end
end

Card = Struct.new(:rank, :suit) do
  def to_s; "#{rank} of #{suit}"; end
end

class Deck
  SUITS = %w(hearts clubs spades diamonds)

thatrubylove

# Conditional reach-around

User = Struct.new(:name, :role) do; end

def greet(user)
  if user.name && user.role
    "Hello, I am an #{user.role} user. My name is #{user.name}."
  elsif user.name
    "Hello, my name is #{user.name}."
  else

thatrubylove

DECK = %w[Ace 2 3 4 5 6 7 8 9 10 Jack Queen King].product(%w[Clubs Diamonds Hearts Spades]).map {|rank, suit| "#{rank} of #{suit}" }

thatrubylove

require 'minitest/autorun'

describe "#lines_after_word(lines, target)" do
  let(:file)  { File.expand_path("../innisfree.txt", __FILE__) }
  let(:lines) { File.readlines(file) }

  it "must return an empty array if no lines include the target word" do
    lines_after_word(lines, "hola").must_equal []
  end
end

thatrubylove

def lines_after_word(lines, target)
  index = lines.find_index {|line| line =~ /#{target}/ }
  index.nil? ? [] : ""
end

thatrubylove

require 'minitest/autorun'

describe "#lines_after_word(lines, target)" do
  let(:lines) { File.readlines(File.expand_path("../innisfree.txt", __FILE__)) }

  it "must return all the lines if the first line includes the target word" do
    lines_after_word(lines, "Innisfree").count.must_equal lines.count
  end
end