awelm

// A case class in Scala is just a typed tuple
case class Person(name: String, title: String)

val person = Person("Joe Smith", "Mr")
val professors = Set("Joe Smith")

val greeting = person match {
	case Person(name, "Dr") =>
		// This block executes if person has the title "Dr"
		s"Welcome Doctor $name"

awelm

// Note all variables declared with `val` are immutable
val opt = Some(5) // type: Option[Int], value: Some(5)

/* 
 * map lets you run a transformation function on the value possibly stored
 * inside the Option. If map is called on an empty Option, then map will skip
 * the transformation function and return None. The first map call below prints
 * the stored value and then adds 2 to it. The second map call wraps the stored
 * value inside another Option, which is why the return value has an extra
 * Option layer. The third call always replaces the stored value with None.

awelm

viewerId = None
subscription = user.getSubscription()

if subscription:
	premiumTier = subscription.getPremiumTier()
	if premiumTier:
		premiumId = premiumTier.getPremiumId()
		if premiumId:
			viewerId = premiumId
		else:

awelm

val viewerId = user.getSubscriptionOpt      // type: Option[Subscription]
	.flatMap(_.getPremiumTierOpt)           // type: Option[Tier]
	.flatMap(_.getPremiumIdOpt)             // type: Option[ID]
	.getOrElse(user.getId())                // type: ID

awelm

// type: Future[String]
val stringFut = Future {
	Thread.sleep(1000)
	"Returned string"
}

/*
 * You can call map() to register a synchronous operation
 * to run once this Future completes successfully
 */

awelm

async def storeWords():
    computedString = await computeString() 
    words = computedString.split(" ")
    await persistWords(words)

asyncio.run(storeWords())

awelm

computeString.map(_.split(" ")).flatMap(persistWords)

awelm

// type: Try[Int], value: Success(6)
val toIntTry = Try {
	"6".toInt
}

// type: Try[Int], value: Success(7)
val incrementedIntTry = toIntTry.map(_+1)

// type: Try[Double], value: Success(7.0)
val toDoubleTry = incrementedIntTry.flatMap { integer =>

awelm

try:
  file = open("a.txt", 'rb')
except Exception:
	try:
	  file = open("b.txt", 'rb')
	except Exception:
		pass

awelm

def openFileTry(name: String): Try[Source] = Try(Source.fromFile(name))

val fileTry = openFileTry("a.txt").getOrElse(openFileTry("b.txt"))