jbranchaud

defmodule Listless do
  def first([]), do: nil
  def first([head|_]) do
    head
  end

  def last([]), do: first []
  def last([head|[]]), do: head
  def last(list) do
    [_|tail] = list

jbranchaud

NUMBER_OF_BLOCKS = 20
GRID_SIZE = NUMBER_OF_BLOCKS + 1

previous_row = Array.new(GRID_SIZE, 1)

(GRID_SIZE-1).times do |_|
  previous_row =
    previous_row.each_with_object([]) do |item,current_row|
      current_row << item + (current_row.last || 0)
    end

jbranchaud

!! EASY

! Using only * and +, how would you calculate 3^2 + 4^2 with Factor?
3 3 * 4 4 * +
clear

! Enter USE: math.functions in the Listener. Now, with sq and sqrt,
! calculate the square root of 3^2 + 4^2.
USE: math.functions
3 sq 4 sq + sqrt

jbranchaud

Round Robin

Given 3 Teams (A, B, C), we want to organize a tournament schedule such that every team plays every other team exactly once. Here is a valid schedule for these 3 teams:

• A - B
• B - C
• A - C

How about if we have N teams? Devise a general purpose algorithm that generates tournament schedules for N teams.

jbranchaud

> {a: 1, b: 2, c: 3}.slice(:a)
=> {:a=>1}
> {a: 1, b: 2, c: 3}.slice!(:a)
=> {:b=>2, :c=>3}

jbranchaud

# with postgres DDL
execute SQL<<-
  create table users(
    ...
    created_at timestamptz not null,
    updated_at timestamptz not null
  );
SQL

# with Rails DSL

jbranchaud

puts '====='

puts 'defining the Parent class with #poop'
class Parent
  def poop
    puts "💩 💩"
  end
end

puts 'defining the Child < Parent class with #poop'

jbranchaud

Clojure Resources

• Getting Started with Clojure in Vim
• Selling Clojure
• How Clojure Babies Are Made

Tutorials

• Clojure for the Brave and True
• Caves of Clojure

jbranchaud

Working With Buffers

Me

• I'm Josh Branchaud
• I work at Hashrocket
• Twitter: @jbrancha
• Github: @jbranchaud

Why talk about buffers?

jbranchaud

White Man Resources

• Ways Men in Tech are Unintentionally Sexist
• Trouble at the Koolaid Point (on Wired)
• The Other Side of Diversity
• Unconcious Bias at Work
• What Men (and Everyone, Really) Can Do To Support Gender Equity in Tech
• So You Want To Be An Ally
• Feminism: How to Be A (Male) Ally
• [Tools for White Guys who are Working for Social Change… and other people socialized in a society based on domination](http://www.xyonline.net/content/to