MateuszKubuszok

sealed trait FList[F[_]] extends Product with Serializable
object FList {
  final case class Last[F[_], A, B](f: A => F[B]) extends FList[F]
  final case class Cons[F[_], A, B, Tail <: FList[F]](f: A => F[B], tail: Tail) extends FList[F]
}

implicit class FunOps[F[_], A, B](f: A => F[B]) extends AnyVal {

  def toFList: FList.One[F, A, B] = FList.One(f)
  

MateuszKubuszok

My public speeches

Actually, more like hall of shame because I cannot watch/listen to myself without cringe, but in this time and age everyone has to be a salesman. Well, not really, but it kind of help with self-development and getting confidence, so whatever. Remember kids! You don't have to be competent to be a public speaker! (Or write a book. Or blog. Or OSS. Or get a job.)

Optimizing Heavy Web Service presentation

• X Tricity Scala User Group
• Gdańsk, at Olivia Business Center, 2016.01.28
• Video at https://www.youtube.com/watch?v=ijhn6qWCUGQ
• Code at https://github.com/MateuszKubuszok/OptimizingHeavyWebServicePresentation

MateuszKubuszok

import scala.language.reflectiveCalls

type Nullary[A] = Unit
type Unary[A]   = A
type Binary[A]  = (A, A)

trait Algebra {
  type Set
  
  type Operation[F[_]]  = F[Set] => Set

MateuszKubuszok

trait TypedSlide[F[_], I <: Int] {
  type Out[A]
  
  def sliding[A](fa: F[A]): F[Out[A]]
}
object TypedSlide {
  type Arbitrary
  class Helper[F[_], I <: Int] {
    def apply[OOut[_]](f: F[Arbitrary] => F[OOut[Arbitrary]]) = new TypedSlide[F, I] {
      type Out[A] = OOut[A]

MateuszKubuszok

#!/bin/bash

brew bundle dump --file Brewfile
/bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/uninstall.sh)"
/bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"
brew bundle install

MateuszKubuszok

type ~>[F[_], G[_]] = [A] => F[A] => G[A]

final case class <~>[F[_], G[_]](to: F ~> G, from: G ~> F):
  val mapAsTo: [A, B] => (G[A] => G[B]) => (F[A] => F[B]) =
    [A, B] => (f: (G[A] => G[B])) => to[A].andThen(f).andThen(from[B])
  val mapAsFrom: [A, B] => (F[A] => F[B]) => (G[A] => G[B]) =
    [A, B] => (f: (F[A] => F[B])) => from[A].andThen(f).andThen(to[B])

extension [F[_], A](fa: F[A])
  transparent inline def mapAs[G[_]]: [B] => (G[A] => G[B]) => F[B] =

MateuszKubuszok

Separate automatic derivation from semiautomatic

Directly solves:

• #166 Ability to not use auto-derivation

General idea of the solution

Currently Chimney attempts to derive as much as possible with a single expression. It inline results on Scala 2 it uses an approach where when implicit is summoned it is expected that only user-provided implicit would be used. This is done because:

MateuszKubuszok

#!/bin/bash

defaultURL='https://github.com/ledgersmb/LedgerSMB'
defaultFILE=''

HELP() {
    cat <<-EOF
        usage: github-badge-cache-buster.sh [ -h | --help | [ repoURL | "auto"   [ badgeFile ] ] ]

               repoURL   defaults to '$defaultURL'