jwhiteman

require "thread"

stage_one    = Queue.new
stage_two    = Queue.new
stage_three  = Queue.new

stage_one_worker = Thread.new do
  100.times do |n|
    stage_one << n
    

jwhiteman

# http://is.gd/NzZxYT

defmodule BinaryTree do
  def invert([n, list]) when is_integer(n) and is_list(list) do
    [n, invert(list)]
  end
  def invert([n, nc, m, mc])
      when is_integer(n) and is_integer(m)
      and is_list(nc) and is_list(mc) do

jwhiteman

sudo apt-get update
sudo apt-get install vim

# generate keys and copy them over
ssh-copy-id -i id_rsa.pub vagrant@hnclient # move node ssh key to the client
# update /etc/hosts on each node to know at least the master; the master about the slave nodes
# make sure master can ssh into localost
cat .ssh/id_rsa.pub >> .ssh/authorized_keys

# re-read: http://stackoverflow.com/questions/8872807/hadoop-datanodes-cannot-find-namenode

jwhiteman

# elixir
defmodule Example do
  def work(_msg) do
    IO.puts "called 1st function"
  end

  def work(_msg, data=[_a, _b, _c]) do
    IO.puts "called 2nd function #{inspect data}"
  end

jwhiteman

curl -H "Content-Type:application/json" -d'{"user_credentials":"YOUR_CREDENTIALS_HERE", "doc":{"name":"kitabu.pdf", "document_type":"pdf", "test":"false", "document_url":"https://dl.dropboxusercontent.com/u/123456789/output/kitabu.pdf.html"}}' http://docraptor.com/docs > kitabu.pdf

jwhiteman

;; letrec practice
;; fold
;; map
;; filter
;; mapcat

(define (fold fold-f acc l)
  (letrec
      ((FOLD (lambda (acc l)
                (cond

jwhiteman

defmodule Ring do
  def node(name, next_pid) do
    receive do
      1 -> 
        send next_pid, 1
      n when is_number(n) ->
        send next_pid, n
        node(name, next_pid)
    end
  end

jwhiteman

% Andrea Leopardi's list parser
% http://andrealeopardi.com/posts/tokenizing-and-parsing-in-elixir-using-leex-and-yecc/
Nonterminals list elems elem.
Terminals '[' ']' ',' int atom.

Rootsymbol list.

list ->
  '[' ']' : [].
list ->

jwhiteman

defmodule MyList do

  # version 1: continuation passing style
  def flatten(l), do: flatten(l, fn (result) -> result end)
  def flatten([], col), do: col.([])
  def flatten([h|t], col) when not is_list(h) do
    flatten(t, fn (acc) -> col.([h | acc]) end)
  end
  def flatten([h|t], col) do
    col.(

jwhiteman

def daemonize_app
  if RUBY_VERSION < "1.9"
    exit if fork     # jettison the terminal
    Process.setsid   # establish a new group & session leader (can only be done as a child process)
    exit if fork     # jettison the group leader. now it can't be interrupted from another group or session going down.
    Dir.chdir "/"    # change dir to root to make sure that the dir won't go away during the process run

    # as a demon we won't be needing these...
    STDIN.reopen  "/dev/null"
    STDOUT.reopen "/dev/null", 'a'