JoelQ

class Tree
  attr_reader :value, :left, :right

  def initialize(value, left, right)
    @value = value
    @left = left
    @right = right
  end

  def reduce(initial, &block)

JoelQ

What does x :: xs pattern matching mean in Elm?

:: is the list prepend operator in Elm.

3 :: 2 :: 1 :: []

is equivalent to

JoelQ

-- 0.19

randomToTask : Generator a -> Task x a
randomToTask generator =
    Time.now
        |> Task.map (Tuple.first << Random.step generator << Random.initialSeed << Time.posixToMillis)


-- 0.18

JoelQ

List of helpful Ellie's I've written

I often write Ellies to demo an idea or to share a solution with someone on Slack. Some of them are helpful enough to share many times so I keep a reference to them here. Others are just cool so I want to save the link 😎

Forms

• Validated Field
• Double-click to edit field
• Formatted number field
• Custom dropdown with "selected" and "focused" states

JoelQ

def add(number1, number2)
  number2.times.reduce(number1) { |total| total.next }
end                                                    

add(2,3)
# => 5

def subtract(number1, number2)
  number2.times.reduce(number1) { |total| total.pred }
end

JoelQ

class Add
  def self.mempty
    new(0)
  end

  def initialize(number)
    @number = number
  end

  attr_reader :number

JoelQ

#!/bin/sh

set -e

echo "== BUILDING THE APP =="
yarn parcel build src/index.html

echo "== CONFIGURING REDIRECTS  =="
if [ "$CONTEXT" = "production" ]; then
  cp production_redirects dist/_redirects

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

Redundant if/else - identity

def can_edit?
  if admin?
    true
  else
    false
  end
end

JoelQ

puts "4 line REPL (read eval print loop)"

$stdin.each_line do |line|        # READ
  return_value = eval(line.chomp) # EVAL
  puts return_value               # PRINT
end                               # LOOP