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// A demonstration of how to make composition a first (or 1.5th) class
// citizen in Scala OO code, as it is better to favor composition
// over inheritance.
//
// The basic idea is to create a sister trait named "MyTraitComposition" to your
// base trait. The composition trait specifies an abstract member "delegate"
// and delegates the full MyTrait interface to that delegate. Later on,
// concrete implementations can implement MyTrait with MyTraitComposition
// to easily extend the behavior of another existing concrete implementation
// via composition.

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//
// A demonstration of using multiple traits to mix in multiple "Before" hooks,
// with an intended usage in test code.
//
// The demonstration shows that multiple traits inheriting BeforeEach (or more
// germanely scalatest's BeforeAndAfterEach) can be sufficiently composable to use
// in our testing toolchain without sewing our own strait jacket.
//

object Main {

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//
// Demonstration on how to use Scala's Either[A, B] type to include error cases in function return values
// and eventually transform those domain errors into more useful end types, like Redirects.
//
// This demonstration uses the example of ordering a product, where ordering can fail for a variety
// of reasons including failure in our payment provider (Stripe) or failure due to insufficient
// product inventory.
//

object Main {

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# make_git_test_tree.sh
#
# This script sets up a git repository with a particular branch layout. Playing around with rebasing and merging
# the branches should help your understanding of git.
#
# Make sure you're in a goddamned empty directory when you execute this script. The script
# shouldn't be in the same directory.
#
# Here's an example, assuming this file is in the current working directory:
#

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/*
 * Let's authenticate an attempted email and password against our database in two different ways
 * using scala. Authentication can fail due to: 
 *   (1) No account matching the e-mail (findByEmail(someEmail) can be either None or Some(Account))
 *   (2) No password being associated with the account (account.password can be either None 
 *       or Some(Password))
 *   (3) The password for the account was incorrect (password.is(attempt) returns true or false)
 *
 * We'll take two different approaches: one using a series of pattern matches and another using
 * for comprehensions. Which is more readable? Which is more idiomatic? <gruff military voice> I'm 

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// This example produces a compiler error in Scala 2.9.1 and 2.9.2. It works fine in Scala 2.10M7.
// The error text is:  "java.lang.Error: symbol value blobKey does not exist in Crasher$$anonfun$1.apply"

object Crasher {
  def main(args: Array[String]) {
    println("This will never be printed because the compiler will crash")
  }
}

class Crasher { // this can be a trait, class, object, whatever

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trait MyService {
  def metricProvider: OtherService1

  // My work goes below
  def getMetrics: Seq[Metric] {
    // code that actually uses dep1 and dep2 to get metrics
  }
}

object MyService extends MyService {

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// This is not a particularly impressive example of using futures.
def getMetrics: List[EgraphsMetric[Int]] = {

  import akka.pattern.{ ask, pipe }

  val futureMetrics: List[Future[EgraphsMetric[Int]]] = for (actor <- actors: List[ActorRef]) yield {
    implicit val timeout = Timeout(5 seconds)

    for {
      metric <- ask(actor, GetMetric).mapTo[EgraphsMetric[Int]]

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package assetproviders {
  import play.api.mvc.Action
  import play.api.mvc.Controller
  import play.api.mvc.AnyContent
  import play.api.mvc.Call

  /**
   * This simple interface is meant to mimic the existing interface in Play 2.0
   * for the Assets controller it provides.  By implementing this it is possible
   * to mix and combine various AssetProviders to create a custom Asset controller

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package controllers

import play.api._
import play.api.mvc._
import play.api.mvc.Results._

/** Imagine that the stuff inside this package is the toybox plugin code */
package toybox {

  /**