JoelQ

User = Struct.new(:name, :age, :profession)

class MonoidBuilder
  def initialize(name: nil, age: nil, profession: nil)
    @name = name
    @age = age
    @profession = profession
  end

  def self.empty

JoelQ

What's up with Html a?

Ever wonder why sometimes the compiler yells at you for using type Html a ? Why is a ok some times but not others?

It's not unique to Html a. Look at the same problem using a simpler type we all understand: List a.

Here are a few questions and thoughts to ponder:

• Compare the myList and myHtml functions. How are they similar? How are they different?
• Why do you think these functions will compile or not compile?

JoelQ

module Main exposing (..)

import Array
import Tuple
import Dict exposing (Dict, get)
import Random exposing (Generator, map)


-- RANDOM

JoelQ

port module Main exposing (..)

import Html.App
import Html exposing (..)
import Html.Attributes exposing (id)


type alias Row =
    List String

JoelQ

namespace :dependencies do
  task :pre_task do
    puts "pre-task"
  end

  task task1: :pre_task do
    puts "task1"
  end

  task task2: :pre_task do

JoelQ

What is Elm

Pure Functions

What does that mean?

• For a given input, you always get the same output
• The output cannot depend on any external factors (e.g. File on disk, some external variable)

JoelQ

Ruby docs for Array#uniq

From the docs:

uniq → new_ary uniq { |item| ... } → new_ary Returns a new array by removing duplicate values in self.

If a block is given, it will use the return value of the block for comparison. It compares values using their hash and eql? methods for efficiency.

JoelQ

import Graphics.Collage exposing (..)
import Graphics.Element exposing (..)
import Color exposing (..)
import Keyboard
import Time
import Debug

-- Model
type alias Model = { x : Float, y : Float, radius: Float }

JoelQ

Server scripts

This is the source for the scripts discussed in https://robots.thoughtbot.com/improving-user-experience-with-shell-scripts

Both scripts are in the bin/ directory of the repo that contains all the markdown documents for blog posts. Users run bin/server and everything is automatically set up for them to view a local preview of the blog. bin/server-setup is a dependency of bin/server and is never run directly by users.

Maitre-d is the name of the "blog engine" discussed in the article.

JoelQ

puts "__dir__ is the same as File.expand_path(__dir__)"
puts __dir__ == File.expand_path(__dir__)

puts "__dir__ is the same as File.expand_path( File.dirname(__FILE__) )"
puts __dir__ == File.expand_path( File.dirname(__FILE__) )

puts "__dir__ is the same as File.expand_path('../', __FILE__)"
puts __dir__ == File.expand_path("../", __FILE__)

# Script Output: