Jules Ivanic guizmaii

Applied Functional Programming with Scala - Notes

1. Mastering Functions

A function is a mapping from one set, called a domain, to another set, called the codomain. A function associates every element in the domain with exactly one element in the codomain. In Scala, both domain and codomain are types.

val square : Int => Int = x => x * x

Recursion and Trampolines in Scala

Recursion is beautiful. As an example, let's consider this perfectly acceptable example of defining the functions even and odd in Scala, whose semantics you can guess:

def even(i: Int): Boolean = i match {
  case 0 => true
  case _ => odd(i - 1)
}

def odd(i: Int): Boolean = i match {

These are my notes for connecting to a meraki client vpn from ubuntu 16.04. This configuration assumes you are using a psk for the ipsec auth.

Install the following packages:

apt-get install -y strongswan xl2tpd

Configure strong swan

Currently, there is an explosion of tools that aim to manage secrets for automated, cloud native infrastructure management. Daniel Somerfield did some work classifying the various approaches, but (as far as I know) no one has made a recent effort to summarize the various tools.

This is an attempt to give a quick overview of what can be found out there. The list is alphabetical. There will be tools that are missing, and some of the facts might be wrong--I welcome your corrections. For the purpose, I can be reached via @maxvt on Twitter, or just leave me a comment here.

There is a companion feature matrix of various tools. Comments are welcome in the same manner.

	require 'dry-types'

	class Carrier
	attr_reader :name

	def initialize(attributes)
	@name = attributes.fetch(:name)
	end
	end

	# You can pass client options directly to the Resource constructor,
	# no need to construct a client yourself
	s3 = Aws::S3::Resource.new(
	credentials: Aws::Credentials.new('akid', 'secret'),
	region: 'eu-west-1'
	)

	s3.bucket('backup').object('dir/subdir/filename.txt').upload_file(local_file)

	#!/bin/bash

	# Installs specified Scala version, and enables colorized REPL

	SCALA_VERSION=2.11.4
	if [ "$1" ]; then SCALA_VERSION=$1; fi

	set -e

	case "$OSTYPE" in

	# DCI EXAMPLE IN RUBY (with some prototype elements)
	# Blog post: https://www.ludyna.com/oleh/dci-example-in-ruby
	#
	# More info:
	#
	# Creator of MVC & DCI, Trygve Reenskaug: DCI: Re-thinking the foundations of
	# object orientation and of programming
	# http://vimeo.com/8235394
	#
	# James Coplien: Why DCI is the Right Architecture for Right Now

	# config/initializers/instrumentation.rb

	# Subscribe to grape request and log with Rails.logger
	ActiveSupport::Notifications.subscribe('grape.request') do \|name, starts, ends, notification_id, payload\|
	Rails.logger.info '[API] %s %s (%.3f ms) -> %s %s%s' % [
	payload[:request_method],
	payload[:request_path],
	(ends-starts)*1000,
	(payload[:response_status] \|\| "error"),
	payload[:x_organization] ? "\| X-Org: #{payload[:x_organization]}" : "",


	f(events) -> state
	match f(state, event) -> state

	f(state, command) -> events