klaeufer

import scala.util.Random
import java.util.concurrent.locks.ReentrantLock

def dinner(number: Int, delayInMs: Int = 10) =
  
  val forks = Array.fill(number)(new ReentrantLock)

  // warning: running each philosopher in their own explicit Java thread
  def phil(i: Int) = new Thread:
    override def run(): Unit =

klaeufer

var shared = 0
val lock = new java.lang.Object

def unsafe =
  val local = shared
  Thread.sleep(0)
  shared = local + 1

def safe =
  lock.synchronized:

klaeufer

def p(s: String) = 
  for i <- 1 to 10 do
    Thread.sleep(500)
    println(s"$i : $s")

// running two or more tasks sequentially
// about 20 seconds by design

val t0 = System.currentTimeMillis
p("a")

klaeufer

// a CPU-intensive task
def isPrime(i: Long): Boolean =
  if i == 2 then return true
  if i < 2 || i % 2 == 0 then return false
  var k = 3L
  val half = i / 2
  while k <= half do
    if i % k == 0 then return false
    k += 2
  true

klaeufer

object KLSigPipeFun:
  def main(args: Array[String]) =
    val lines = scala.io.Source.stdin.getLines()
    val lineNumbers = Iterator.from(1)
    val numberedLines = lineNumbers.zip(lines)
    val okLines = numberedLines takeWhile: _ => 
      !scala.sys.process.stdout.checkError()
    val outLines = okLines map:
      case (number, line) => println(s"$number: line")
    println(s"${outLines.length} lines counted")

klaeufer

#!/bin/bash

# Copyright 2024 Konstantin Läufer <laufer AT cs.luc.edu>
#
# 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
#

klaeufer

import Mathlib.Data.List.Basic

section
-- BEGIN

-- https://lean-lang.org/blog/2024-1-11-recursive-definitions-in-lean/


-- TODO make tail-recursive?

klaeufer

import Mathlib.Data.Nat.Factorization.Basic
import Mathlib.Data.Nat.Prime.Basic
open Nat
open Prime

section
-- BEGIN


def claim := ∀ p : Prop, ∀ q : Prop, p → (q → p)

klaeufer

// see also https://www.implicitdef.com/2015/11/19/comparing-scala-http-client-libraries.html

// task: use the prime checker webservice
// https://github.com/LoyolaChicagoCode/primenumbers-spray-scala
// to count the number of primes within a given range

/* instructions: create a build.sbt file in your project root folder containing the following lines:

scalaVersion := "3.3.3"

klaeufer

[
  {
    "breed": "Abyssinian",
    "country": "Ethiopia",
    "origin": "Natural\/Standard",
    "coat": "Short",
    "pattern": "Ticked"
  },
  {
    "breed": "Aegean",