marc0der

Functional error handling in Kotlin

Agenda:

• About the (simple) exercise
• Higher Order Functions
• Throwing exceptions: here be dragons!!
• Sentinel values: better but not great
• The Option: error as an ADT
• Functional combinators: add some sugar

marc0der

class ForST private constructor() {
    companion object
}

typealias STOf<S, A> = arrow.Kind2<ForST, S, A>

typealias STPartialOf<S> = arrow.Kind<ForST, S>

@Suppress("UNCHECKED_CAST", "NOTHING_TO_INLINE")
inline fun <S, A> STOf<S, A>.fix(): ST<S, A> = this as ST<S, A>

marc0der

================================================================================
Available Java Versions
================================================================================
Vendor         | Current | Version       | Status           | Identifier
--------------------------------------------------------------------------------
AdoptOpenJDK   |         | 12.0.1.j9     | available        | 12.0.1.j9-adpt
               |   >>>   | 12.0.1.hs     | available        | 12.0.1.hs-adpt
               |         | 11.0.3.j9     | installed        | 11.0.3.j9-adpt
               |         | 11.0.3.hs     | available        | 11.0.3.hs-adpt
               |         | 8.0.212       | available        | 8.0.212-adpt

marc0der

object Main extends App {
  RatpackServer.start { spec =>
    spec.serverConfig(c => c.env())
      .registry(Guice.registry(g => g.bind(classOf[VersionHandler])))
      .handlers(chain => chain.get("version", classOf[VersionHandler]))
  }
}

case class VersionConfig(@BeanProperty appName: String, @BeanProperty appVersion: String)

marc0der

buildscript {
  repositories {
    maven { url "https://plugins.gradle.org/m2/" }
  }
  dependencies {
    classpath "com.gradle.publish:plugin-publish-plugin:0.9.6"
    classpath "com.netflix.nebula:nebula-kotlin-plugin:1.0.3"
  }
}

marc0der

#!/bin/bash

#Tweak this if need be for you system!
TARGET_VOLUME="/Volumes/Macintosh HD"

DMG_NAME="jdk-8u101-macosx-x64.dmg"
MOUNT_VOLUME="/Volumes/JDK 8 Update 101"
SHA_256="680de8ddead3867fc34e7ff380f437c7ddb8dc75eb606186a3e8ae7e3b8c7fbc"

echo "Getting the DMG..."

marc0der

#bin/bash

SESSION="gradle"
tmux -2 new-session -d -s $SESSION
tmux new-window -t $SESSION:1 -n 'benchmark'
tmux split-window -v
tmux select-pane -t 0
tmux send-keys "clear" C-m
tmux send-keys "docker run -it marc0der/gradle:1 zsh" C-m
tmux send-keys "sdk use gradle 2.12" C-m

marc0der

#!/usr/bin/env groovy

@Grab("org.codehaus.geb:geb-core:0.7.2")
@Grab("org.seleniumhq.selenium:selenium-chrome-driver:2.48.2")

import geb.*
import java.security.MessageDigest

import static java.net.URLDecoder.decode

marc0der

### Keybase proof

I hereby claim:

  * I am marc0der on github.
  * I am marcovermeulen (https://keybase.io/marcovermeulen) on keybase.
  * I have a public key whose fingerprint is 4EF1 482E D60C 7CBF C1EB  40AC 33E7 5AD0 46EF 18C4

To claim this, I am signing this object:

marc0der

$ gvm flush candidates
$ gvm install jbossforge
$ forge