Olivier Mélois Baccata

Advanced 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

Fantastic meetings and where to find them

Anecdotally most people in software industry hates meetings, because meeting is a soul-sucking dementor. Jokes aside, I think it's fair to say that people feel meeting is taking too much time, and the process is often painful.

In this post, I'll try to provide a few rules of thumb that I believe can make meeting less painful and more efficient.

Rule 1: Always reiterate your goal before start

How many times you attend a meeting without a goal in mind?

	package baccata

	/**
	* Inspired from Grant Beaty's Scunits
	*/
	trait Bool {
	type branch[B,T <: B, E <: B] <: B // typelevel if-then-else
	type not <: Bool
	type or[R <: Bool] <: Bool
	type and[R <: Bool] <: Bool

	module Main where
	main = putStrLn (show (fforall (\x -> (x >= -1000)) (setInt)))

	type Set a = a -> Bool

	setInt :: Set Int
	setInt = \x -> True

	--filtering the range with the set function and checking if all elements from the set satisfy the predicate
	fforall :: Restrict a => (a -> Bool) -> Set a -> Bool

	import shapeless._

	//////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
	// THE IMPLICIT CLASS THAT ALLOWS TO CALL #copy ON ANY SEALED TRAIT INSTANCE
	//////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

	object copySyntax {

	implicit class CopySyntax[TypeToCopy](thingToCopy: TypeToCopy) {

	#!/bin/bash
	#Script to get all repositories under a user or team from bitbucket
	#Usage: cloneAllBitbucket [username] [user_or_team]

	curl -u ${1} https://api.bitbucket.org/1.0/users/${2} \
	\| jsawk 'return this.repositories.map(function(item){return item.name;})' \
	\| jsawk -n 'out(this)' \
	\| sed -e 's/^"//' -e 's/"$//' > repos

	for repo_name in `cat repos`

	import com.google.protobuf.Descriptors.{MethodDescriptor, ServiceDescriptor}
	import com.trueaccord.scalapb.compiler.FunctionalPrinter.PrinterEndo
	import com.trueaccord.scalapb.compiler._

	import scala.collection.JavaConverters._

	final class MonixGrpcPrinter(service: ServiceDescriptor,
	override val params: GeneratorParams)
	extends DescriptorPimps {

	import cats.free.Free
	import cats.{ Monad, ~> }

	object KVStoreExample {

	sealed trait KVStore[A]
	case class Put[T](key: String, value: T) extends KVStore[Unit]
	case class Get[T](key: String) extends KVStore[Option[T]]

	object KVStore {

	import akka.actor.{ Actor, ActorSystem, Props }
	import akka.util.Timeout
	import cats._
	import cats.data.State

	class ActorInterpreter[G[_], StateData](
	actorSystem: ActorSystem,
	initialData: StateData,
	stateInterpreter: G ~> Lambda[A => State[StateData, A]]
	)(implicit t: Timeout, ec: ExecutionContext)

	// *****************************************************************************
	// Projects
	// *****************************************************************************

	lazy val `polykind-tests` =
	project
	.in(file("."))
	.enablePlugins(AutomateHeaderPlugin, GitVersioning)
	.settings(settings)
	.settings(