edreyer

// our data model
data class Person(val name: String, val age: Int, val email: String)

// vanilla Kotlin 
fun createPerson(name: String?, age: Int?, email: String?): Person? =
    name?.let { n ->
        age?.let { a ->
            email?.let{ e ->
                Person(n, a, e);
            }

edreyer

import kotlinx.coroutines.launch
import kotlinx.coroutines.newSingleThreadContext
import kotlinx.coroutines.runBlocking

// inspired by: https://dzone.com/articles/print-even-and-odd-numbers-using-two-threads-compl

// You can run this in a Kotlin REPL

fun main() = runBlocking {
  (1..100).forEach {

edreyer

import kotlinx.coroutines.async
import kotlinx.coroutines.coroutineScope
import kotlinx.coroutines.flow.Flow
import kotlinx.coroutines.reactive.asFlow
import kotlinx.coroutines.reactor.awaitSingle
import reactor.core.publisher.Flux
import reactor.core.publisher.Mono

typealias Workflow<R> = suspend () -> Result<R>
typealias MonoWorkflow<R> = suspend () -> Mono<R>

edreyer

import io.vavr.control.Try;
import java.util.concurrent.Future;
import org.springframework.scheduling.annotation.Async;
import org.springframework.scheduling.annotation.AsyncResult;

class Foo {}

interface FooService {
  /** Returns Future<Try<T>> for better exception handling */
  @Async

edreyer

sealed trait Quantity

object Quantity {
  final case class UnitQuantity private (units: Int) extends Quantity
  final case class WeightQuantity private (kgs: Double) extends Quantity  
  
  // factory with validation
  object UnitQuantity {
    def create(units: Int): Either<ValidationError, UnitQuantity> =
      if (units <= 0) Either.left(ValidationError("units must be positive")) 

edreyer

import java.util.ArrayList;
import java.util.List;
import java.util.Objects;
import java.util.Optional;
import java.util.function.Consumer;
import java.util.function.Function;
import java.util.function.Predicate;
import java.util.function.Supplier;

/**

edreyer

package techtalk;

import com.jnape.palatable.lambda.adt.hlist.Tuple2;
import com.jnape.palatable.lambda.functions.Fn1;
import com.jnape.palatable.lambda.functions.Fn2;
import io.vavr.collection.HashMap;
import io.vavr.collection.Map;

import static com.jnape.palatable.lambda.adt.hlist.HList.tuple;
import static com.jnape.palatable.lambda.functor.builtin.State.state;