Sebastian sklppr

Refresher on anti-patterns and best practices

Most important basic philosophy “simple vs. easy”: Rails Conf 2012 Keynote: Simplicity Matters by Rich Hickey (Slides)

You probably know this already and in Ruby not all of it is done “explicitly” but it’s important to have these principles in mind when getting to know the following architecture concepts.

STUPID: Singleton, Tight Coupling, Untestability, Premature Optimization, Indescriptive Naming, Duplication
SOLID: Single Responsibility, Open/Closed, Liskov Substitution, Interface Segregation, Dependency Inversion

Select all elements in a that are greater than 5 and multiply them by 2.

Ruby

a.select { |x| x > 5 }.map { |x| x * 2 }

a.find_all { |x| x > 5 }.collect { |x| x * 2 }

a.inject([]) { |b, x| x &gt; 5 ? (b &lt;&lt; x * 2) : b }

Books on Design

General

Design is a Job (Mike Monteiro)
The Design of Everyday Things (Don Norman)
Emotional Design (Don Norman)
Universal Principles of Design: A Cross-Disciplinary Reference (William Lidwell)
Designed for Use (Lukas Mathis)
The Shape of Design (Frank Chimero)

	module Tree0 {

	type Tree<T> = Empty \| Node<T>;

	class Empty {
	public toString(): string {
	return "Empty";
	}
	}

	#!/bin/bash
	# Install a custom R version, https://www.r-project.org/
	#
	# Add at least the following environment variables to your project configuration
	# (otherwise the defaults below will be used).
	# * R_VERSION
	#
	# Include in your builds via
	# source /dev/stdin <<< "$(curl -sSL https://gist.githubusercontent.com/sklppr/cec1b80642e02a12d4e57bc51d803c2e/raw/089ca9b56d6b2364df29db4e78039c3404ce437f/r.sh)"
	R_VERSION=${R_VERSION:="3.3.0"}

	module SnakeCase
	refine String do
	def snake_case
	self.gsub(/::/, '/')
	.gsub(/([A-Z]+)([A-Z][a-z])/,'\1_\2')
	.gsub(/([a-z\d])([A-Z])/,'\1_\2')
	.tr("-", "_")
	.downcase
	end
	end

	require "forwardable"

	module ActiveRecord

	class Base

	def save
	puts "SAVED #{name}"
	end

	#!/usr/bin/env ruby

	require "fileutils"
	require "redcarpet"

	OUTPUT_FOLDER = "html"

	HTML_TEMPLATE = <<-HTML
	<!DOCTYPE html>
	<html>

	def coupon(parts: 4, chars: 4, separator: "-")
	SecureRandom.hex(parts*chars/2).upcase.scan(%r/.{#{chars}}/).join(separator)
	end


	# encoding: utf-8

	#####################################################################################
	#
	# Fetches info about the people you follow on Twitter
	# and determines who you could/should unfollow based on:
	# - activity: was their last update more than 3 months ago?
	# - popularity: do they have less than 25 followers?
	# - mass following: are they following more than 10000 people?