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Loïc Descotte loicdescotte

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loicdescotte / zioSplitLines.scala
Last active May 2, 2020 03:50
ZIO change stream framing. Example : delimit by lines
import zio._
import zio.stream._
import zio.console._
val streamIn = Stream.fromIterable(Set("first line\nsecond line\nthird ", "line"))
// or ZSink.splitDelimiter("\n")
val streamOut = streamIn.transduce(ZSink.splitLines).flatMap(chunk => Stream.fromChunk(chunk))
val runtime = new DefaultRuntime {}
runtime.unsafeRun(streamOut.map(_.replaceAll("\n","")).foreach(i => putStrLn(i)))
@loicdescotte
loicdescotte / PlayDynamicSource.scala
Last active November 6, 2021 00:41
Play Framework Dynamic Akka Streams Source
def streamWithQueue = Action {
implicit val myExecutionContext: ExecutionContext = actorSystem.dispatchers.lookup("queue-context")
val (queue: SourceQueueWithComplete[String], source: Source[String, NotUsed]) = {
Source.queue[String](100, OverflowStrategy.backpressure).preMaterialize
}
// simulate a background process feeding the queue
Future.traverse((1 to 1000).toList) { i =>
@loicdescotte
loicdescotte / App.scala
Last active September 3, 2019 15:34
Slinky React Hooks example
package hello.world
import slinky.web.html._
import slinky.core.facade.Hooks._
import slinky.core.FunctionalComponent
import scala.scalajs.js
import scala.scalajs.js.annotation.JSImport
@JSImport("resources/App.css", JSImport.Default)
@js.native
@loicdescotte
loicdescotte / accumulateErrors.scala
Last active September 30, 2019 13:23
Accumulate errors with Either and Cats (based on Cats documentation but with Error ADT and NonEmptyChain)
import cats.implicits._
import cats.data._
import NonEmptyChain._
case class Name(value: String)
case class Age(value: Int)
case class Person(name: Name, age: Age)
trait Error
case object ParsingError extends Error
@loicdescotte
loicdescotte / fpmax.scala
Created March 3, 2019 09:41 — forked from jdegoes/fpmax.scala
FP to the Max — Code Examples
package fpmax
import scala.util.Try
import scala.io.StdIn.readLine
object App0 {
def main: Unit = {
println("What is your name?")
val name = readLine()
@loicdescotte
loicdescotte / dropElementInList.re
Created January 31, 2019 15:46
ReasonML : drop element in list
let dropListElement = (n, list) => {
let rec aux = (i, list) =>
switch list {
| [] => []
| [x, ...xs] => i == n ? xs : [x, ...aux(i + 1, xs)]
};
aux(0, list);
};
@loicdescotte
loicdescotte / compose.kt
Last active January 15, 2019 09:55
Compose errors (or nullables) and async functions in Scala, Kotlin, Typescript
import arrow.core.Either
import arrow.core.Either.Companion.left
import arrow.core.Either.Companion.right
import arrow.core.Option
import arrow.core.Some
import arrow.core.flatMap
import arrow.instances.either.monad.binding
import kotlinx.coroutines.async
import kotlinx.coroutines.delay
import kotlinx.coroutines.runBlocking
@loicdescotte
loicdescotte / EitherOps.scala
Last active December 17, 2018 13:13
Either ops to accumumate errors (and symmetric right method)
import scala.util._
implicit class EitherLeftOps[L](eithers: Seq[Either[L,_]]){
def collectLefts: Seq[L] = eithers.collect {
case Left(l) => l
}
}
implicit class EitherRightOps[R](eithers: Seq[Either[_,R]]){
def collectRights: Seq[R] = eithers.collect {
@loicdescotte
loicdescotte / catsSequenceFunctions.scala
Last active September 12, 2018 13:38
Cats sequence functions
import cats.implicits._
val f = (x: Int) => x+1
val g = (x: Int) => x+2
val h = (x: Int) => x+3
// Cats has an Applicative instance for Function1 so you can traverse/sequence it
val l = List(f, g, h).sequence //l : Function1[Int, List[Int]]
l(1) //List(2, 3, 4)
@loicdescotte
loicdescotte / pipe.scala
Created July 13, 2018 14:43
Scala pipe function operator
implicit class AnyEx[T](val v: T) extends AnyVal {
def |>[U](f: T ⇒ U): U = f(v)
}
//example
def f(l: List[Int]) = l.filter(x => x >1)
def g(l: List[Int]) = l.filter(x => x <3)
List(1,2,3) |> f |> g //List(2)