Olivier Mélois Baccata

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

This notes is written by Sheldon. You can find me with #iOSBySheldon in Github, Youtube, Facebook, etc.

Need

Convert .mov/.MP4 to .gif

Reason

As a developer, I feel better to upload a short video when I create the pull request to show other viewers what I did in this PR. I tried .mov format directly got after finishing recording screen using Quicktime, however, gif offers preview in most web pages, and has smaller file size.

This is not limited to developer, anyone has this need can use this method to convert the files.

Fibers

Fibers are an abstraction over sequential computation, similar to threads but at a higher level. There are two ways to think about this model: by example, and abstractly from first principles. We'll start with the example.

(credit here is very much due to Fabio Labella, who's incredible Scala World talk describes these ideas far better than I can)

Callback Sequentialization

Consider the following three functions

	/*
	Copyright 2013 Viktor Klang
	Licensed under the Apache License, Version 2.0 (the "License");
	you may not use this file except in compliance with the License.
	You may obtain a copy of the License at
	http://www.apache.org/licenses/LICENSE-2.0
	Unless required by applicable law or agreed to in writing, software
	distributed under the License is distributed on an "AS IS" BASIS,
	WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	See the License for the specific language governing permissions and

	import cats.data.{ EitherT, State }
	import cats.implicits._
	import cats.{ Monad, ~> }
	import io.aecor.liberator.macros.free
	import io.aecor.liberator.syntax._
	import io.aecor.liberator.{ ProductKK, Term }

	@free
	trait Api[F[_]] {
	def doThing(aThing: String, params: Map[String, String]): F[Either[String, String]]

	package teikametrics

	import cats.effect.implicits._
	import cats.effect.{ContextShift, ExitCase, Sync, Timer}
	import cats.syntax.all._

	import scala.concurrent.ExecutionContext
	import scala.concurrent.duration.FiniteDuration

	object JavaFuture {