pragdave

defmodule Reflect do
  use Application.Behaviour

  def run do
    path = :code.lib_dir(:elixir, :ebin)
    load_modules_in(path)
    modules = for {name,_} <- :code.all_loaded, 
                  Regex.match?(~r/^[A-Z]/, atom_to_binary(name)), 
              do: name

pragdave

defmodule Bitmap do
  defstruct value: 0

  defimpl Access do
    use Bitwise
    def access(%Bitmap{value: value}, bit) do
      if (value &&& (1 <<< bit)) == 0, do: 0, else: 1
    end
  end

pragdave

defmodule Bitmap do
  defstruct value: 0

end

defimpl Access, for: Bitmap do
  use Bitwise
   def access(%Bitmap{value: value}, bit) do
    if (value &&& (1 <<< bit)) == 0, do: 0, else: 1    
  end

pragdave

#
# Given a list, return a new list with all occurrences of consecutive 
# duplicated elements replaced by `{element, count}`
#
#    compress [ 1,2,2,3,4,4,4,5,6,6]
#        → [1, {2, 2}, 3, {4, 3}, 5, {6, 2}]
#

# This version uses the head of the result to give the effect of lookahead

pragdave

[elixir/Book] svn commit -m 'prep for 0.15'                                                                       [Book:158836]
Sending        Changes.pml
Sending        Enumeration.pml
Sending        Introduction.pml
Sending        Nodes.pml
Sending        OTP-applications.pml
Sending        OTP-servers.pml
Sending        OTP-supervisors.pml
Sending        Project.pml
Sending        Protocols.pml

pragdave

Card = Struct.new(:rank, :suit)
dealer = Fiber.new do
  ranks = (1..13).to_a
  suits = [:club, :diamond, :heart, :spade]
  pack = ranks.product(suits).map {|card| Card.new(*card)}
  all_cards = pack*7
  cards = []
  loop do
    cards = all_cards.shuffle if cards.size < 2*52
    Fiber.yield cards.pop

pragdave

provision_list:

  ############################################
  "staging-apps+search":
  ############################################
    env:    staging
    count:  1

    roles:
      master: yes   # has all the background services (cron)

pragdave

  validates_presence_of     :title, :description, :image_url
  validates_numericality_of :price, :greater_than => 0 
  validates_uniqueness_of   :title
  validates_format_of       :image_url, 
                            :with => %r{\.(gif|jpg|png)$}i, 
                            :message => 'must be a URL for GIF, JPG or PNG image.'

pragdave

  validates :title, :description, :image_url, :presence => true 
  validates :price, :numericality => { :greater_than => 0 }
  validates :title, :uniqueness => true
  validates :image_url, 
            :format => { :with  => %r{\.(gif|jpg|png)$}i, 
                         :message => 'must be a URL for GIF, JPG or PNG image.' }

pragdave

Stephenson, G. R. (1967). Cultural acquisition of a specific learned response among rhesus monkeys. In: Starek, D., Schneider, R., and Kuhn, H. J. (eds.), Progress in Primatology, Stuttgart: Fischer, pp. 279-288.

mentioned in: Galef, B. G., Jr. (1976). Social Transmission of Acquired Behavior: A Discussion of Tradition and Social Learning in Vertebrates. In: Rosenblatt, J.S., Hinde, R.A., Shaw, E. and Beer, C. (eds.), Advances in the study of behavior, Vol. 6, New York: Academic Press, pp. 87-88:

[...] Stephenson (1967) trained adult male and female rhesus monkeys to avoid manipulating an object and then placed individual naïve animals in a cage with a trained individual of the same age and sex and the object in question. In on case, a trained male actually pulled his naïve partner away from the previously punished manipulandum during their period of interaction, whereas the other two trained males exhibited what were described as "threat facial expressions while in a fear posture" when a naïve animal appro