Copyright © 2016-2018 Fantasyland Institute of Learning. All rights reserved.
A function is a mapping from one set, called a domain, to another set, called the codomain. A function associates every element in the domain with exactly one element in the codomain. In Scala, both domain and codomain are types.
val square : Int => Int = x => x * x
| sealed trait Interact[A] | |
| case class Ask(prompt: String) | |
| extends Interact[String] | |
| case class Tell(msg: String) | |
| extends Interact[Unit] | |
| trait Monad[M[_]] { | |
| def pure[A](a: A): M[A] |
| package com.nicta | |
| package rng | |
| import scalaz._, Scalaz._, effect._ | |
| // A data type representing a person. | |
| // We are going to produce random instances. | |
| // Note that this data type is recursive. | |
| // The `children` field holds 0 or many Person instances. | |
| case class Person(name: String, age: Int, surname: Option[String], children: List[Person]) |
| Latency Comparison Numbers (~2012) | |
| ---------------------------------- | |
| L1 cache reference 0.5 ns | |
| Branch mispredict 5 ns | |
| L2 cache reference 7 ns 14x L1 cache | |
| Mutex lock/unlock 25 ns | |
| Main memory reference 100 ns 20x L2 cache, 200x L1 cache | |
| Compress 1K bytes with Zippy 3,000 ns 3 us | |
| Send 1K bytes over 1 Gbps network 10,000 ns 10 us | |
| Read 4K randomly from SSD* 150,000 ns 150 us ~1GB/sec SSD |