arosien

<?xml version="1.0" encoding="UTF-8" ?>

<configuration>

	<appender name="CONSOLE"
		class="ch.qos.logback.core.ConsoleAppender">
		<layout class="ch.qos.logback.classic.PatternLayout">
			<Pattern>%X{traceId} %X{spanId} - %m%n</Pattern>
		</layout>
	</appender>

arosien

//> using scala 2
//> using toolkit typelevel:latest

// https://practicalocaml.com/how-to-build-type-safe-state-machines-using-type-state/

// type 'state fsm = { state: 'state }
case class Fsm[State](state: State)

/*
type id

arosien

• I set a breakpoint in pcap.dfdl.xsd on line 168 (first use of the Ethernet element).
• I start the debug session. This pauses at the beginning of the parse, and I hit "Continue" which then breaks on line 168 (Ethernet element).
• I open the ethernetIP.dfdl.xsd file via normal VSCode File->Open commands. I add a breakpoint to line 68 (declaration of MACDest element).
• I press "Continue" and the ethernet breakpoint is hit.
• If I click on the Call Stack where MACDest is at the top of the stack, a different view of MACDest is shown: it is from within the ethernetIP jar file. I suspect this is from a plugin I have installed locally (https://marketplace.visualstudio.com/items?itemName=wmanth.jar-viewer ?), but I'm not sure and would need external validation for.

I am surprised that the separately-opened xsd breakpoint is correctly mapped, but it seems to work for me.

arosien

import cats.Applicative
import cats.arrow.Arrow
import cats.implicits._

/**
  Theorem 1.1 (Cayley representation for (Set) monoids)
  Every monoid (M,⊕,e) is a sub-monoid of the monoid of endomorphisms on M.

  Notions of Computation as Monoids
  EXEQUIEL RIVAS, MAURO JASKELIOFF

arosien

Tag	Implication	Expectation
(no tag specified)	Free form, interpret it as you will.	Context dependent.
Bug	Reviewer is concerned that the code in question could cause problems in production.	Reviewer’s expectation is that the bug will be acknowledged, corrected or explained in some form.
Question	Reviewer has general questions that may warrant addressing before a merge.	Reviewer’s expectation is that the question will be acked or answered in some form.
Concern	This is something to consider an important issue and a response would be appreciated.	Reviewer’s expectation is that there will be a response most of the time.
Suggestion	Reviewer thinks code could be improved, but change is not necessary.	Reviewer expects submitter to consider if change is desirable/worthwhile and respond appropriately.
Nit	This is a weakly held opinion, I'm putting it out there, but if you ignore it, no big deal.	Reviewer has no expectatio

arosien

final case class PasswordValue(value: String) {
  override def toString = "PasswordValue(****)"
}

object SafePassword {
  def resource[F[_]: Sync](value: String): F[Resource[F, PasswordValue]] =
    for {
      used <- Ref.of[F, Boolean](false)
      chars = value.toCharArray
      givePasswordAndNullify = Sync[F].delay {

arosien

import cats._
import cats.implicits._
import cats.effect.IO
import scala.io.StdIn

// Port of https://gist.github.com/danidiaz/112c5de83dc9c9b2ece1bf4d3581da24 to Scala

/** An algebraic data type for expressions to add and multiply integers. */
sealed trait Exp

arosien

import cats.effect.IO
import java.io.ByteArrayOutputStream

val out = new ByteArrayOutputStream
val cookies = IO(println("cookies"))
Console.withOut(out) { cookies.unsafeRunSync() }
out.toString // "cookies\n"

arosien

Functional Programming Demystification

• Scala at the Sea: 19 May 2020
• Adam Rosien @arosien
• Inner Product @InnerProductLLC inner-product.com

Functional programming is full of Fancy Words™. Let's collect a list of them to demystify together. Adam will facilitate with live-coding, and will also try to make good jokes.

Here's some terms to bootstrap us: effect, free monad, functor, property-based testing, refinement type, stream, etc. >

arosien

case class RoseF[V, A](root: V, children: List[A])

object RoseF {
  type Fixed[V] = Fix[RoseF[V, ?]]

  implicit def traverse[V]: Traverse[RoseF[V, ?]] =
    new DefaultTraverse[RoseF[V, ?]] {
      def traverse[G[_]: Applicative, A, B](
          fa: RoseF[V, A]
      )(f: A => G[B]): G[RoseF[V, B]] =