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Mateusz Kubuszok MateuszKubuszok

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View bijectionK.scala
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 /
Last active Jan 7, 2022
Migrate brew from Intel to M1 after transfer
brew bundle dump --file Brewfile
/bin/bash -c "$(curl -fsSL"
/bin/bash -c "$(curl -fsSL"
brew bundle install
View TypedSliding.scala
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 / algebras.scala
Last active Mar 2, 2021
Algebras implementation which isn't based on nested type hierarchy
View algebras.scala
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 /
Last active Nov 17, 2022
My public speeches, presentations and and stuff

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

View FList.scala
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)

Keybase proof

I hereby claim:

  • I am mateuszkubuszok on github.
  • I am mateuszkubuszok ( on keybase.
  • I have a public key ASDad2uAPXJRFF-i7B7nKeQixgIFu5bVsXJLqD7jJGRg0Ao

To claim this, I am signing this object:

MateuszKubuszok / flame-graph-cpu-reverse.svg
Created Aug 31, 2020
Flame graphs for FizzBuzzBenchmark - Things that you need to know about JVM (that matter in Scala)
View flame-graph-cpu-reverse.svg
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MateuszKubuszok / .dotsync.yml
Last active Aug 13, 2020
Utility for copying dotfiles from HOME to some backup directory e.g. git/Dropbox/etc
View .dotsync.yml
backup: .dotsync_bck
- .bashrc
- .zshrc
exclude: []
- .snxrc
View Test2$.java
Compiled from "Test2.scala"
public final class Test2$ {
public static final Test2$ MODULE$;
public static {};
0: new #2 // class Test2$
3: dup
4: invokespecial #20 // Method "<init>":()V
7: putstatic #22 // Field MODULE$:LTest2$;