lbialy

$ sbt new http4s/http4s.g8 --branch 1.0-scala3 
// use all the defaults, just set sbt to 1.9.9

$ cd quickstart

$ sbt assembly

$ cat Dockerfile # create this file with these contents:
FROM ghcr.io/graalvm/jdk-community:22
RUN mkdir /opt/app

lbialy

//> using scala 3.4.0

import language.experimental.captureChecking

class DbCon:
  def runUpdate(): Unit = println(s"runUpdate on ${Thread.currentThread()}")
  def close(): Unit = println("closing DbCon")

def transact[A](f: DbCon^ => A): A =
  val dbCon = DbCon()

lbialy

//> using scala 3.3.3
//> using jvm graalvm-java21:21.0.2
//> using dep com.softwaremill.ox::core:0.0.21

import ox.*
import java.util.concurrent.*

@main def main = supervised {
  val queue = ArrayBlockingQueue[Int](5)

lbialy

import scala.quoted.*

extension (using quotes: Quotes)(repr: quotes.reflect.TypeRepr)
  def flatMapResultType(f: quotes.reflect.TypeRepr => Option[quotes.reflect.TypeRepr]): Option[quotes.reflect.TypeRepr] = 
    import quotes.reflect.*
    repr match
      case MethodType(paramNames, paramTypes, resultType) =>
        resultType.flatMapResultType(f).map(tp => MethodType(paramNames)(_ => paramTypes, _ => tp))
      // case PolyType => // should not appear here
      case tp =>

lbialy

//> using dep com.github.ghostdogpr::caliban-quick:2.5.0

enum Origin {
  case EARTH, MARS, BELT
}

case class Character(
  name: String,
  nicknames: List[String],
  origin: Origin

lbialy

//> using scala "3.3.1"
//> using lib "co.fs2::fs2-io:3.9.3"

import scala.util.*
import scala.io.Source

def safePrintln(s: Any): Either[Throwable, Unit] =
  try Right(println(s))
  catch case err: Throwable => Left(err)

lbialy

// AppKt.java
package hello;

import kotlin.Metadata;
import kotlin.coroutines.Continuation;
import kotlin.coroutines.CoroutineContext;
import kotlin.jvm.functions.Function0;
import kotlin.jvm.functions.Function2;
import kotlin.jvm.internal.Intrinsics;
import kotlin.jvm.internal.SourceDebugExtension;

lbialy

<?xml version="1.0" encoding="UTF-8"?>
<project
        xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"
        xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">

    <modelVersion>4.0.0</modelVersion>

    <groupId>org.jetbrains.kotlin.examples</groupId>
    <artifactId>hello-world</artifactId>
    <version>1.0-SNAPSHOT</version>

lbialy

A structured concurrency response to https://twitter.com/alexelcu/status/1710305127729438994

I am using Ox and JDK 21 in this gist.

First run: docker run --name test-postgres -p 5432:5432 -e POSTGRES_PASSWORD=postgres -d postgres

Then: scala-cli run ox-jdbc.scala

lbialy

#!/usr/bin/env bash

username=
password=
stagedRepositoryId=

while [ "$1" != "" ]; do
    case $1 in
        -u | --username)
            shift