jdegoes

package fpmax

import scala.util.Try
import scala.io.StdIn.readLine

object App0 {
  def main: Unit = {
    println("What is your name?")

    val name = readLine()

djspiewak

Thread Pools

Thread pools on the JVM should usually be divided into the following three categories:

1. CPU-bound
2. Blocking IO
3. Non-blocking IO polling

Each of these categories has a different optimal configuration and usage pattern.

d1egoaz

If you want to learn Scala, I’d suggest:

• Install IntelliJ + Scala Plugin
• Don’t do the Coursera courses yet.
• Don’t do the “red book” Functional Programming in Scala yet.
• Do: http://underscore.io/books/
  • Essential Scala
  • Essential Play
  • Essential Slick
• Do Scala for the Impatient: https://www.amazon.com/Scala-Impatient-Cay-S-Horstmann/dp/0321774094
• The Neophyte’s Guide to Scala http://danielwestheide.com/scala/neophytes.html

cb372

Welcome to the Ammonite Repl 0.8.0
(Scala 2.11.8 Java 1.8.0_91)

@ import scala.util.Try
import scala.util.Try

@ val listOfTries: List[Try[String]] = List(Try("a"), Try("b"), Try("c"))
listOfTries: List[Try[String]] = List(Success("a"), Success("b"), Success("c"))

// I have a List[Try[String]] but I actually want a Try[List[String]].

jdegoes

Applied Functional Programming with Scala - Notes

Copyright © 2016-2018 Fantasyland Institute of Learning. All rights reserved.

1. Mastering Functions

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

heathermiller

This cheat sheet originated from the forum, credits to Laurent Poulain. We copied it and changed or added a few things.

Evaluation Rules

• Call by value: evaluates the function arguments before calling the function
• Call by name: evaluates the function first, and then evaluates the arguments if need be

    def example = 2      // evaluated when called
    val example = 2      // evaluated immediately

allomov

Variables

Code	Meaning
var x = 5	variable
✅ val x = 5 ❌ x=6	constant
var x: Double = 5	explicit type

Functions

aponxi

SQL to MongoDB Mapping Chart

SQL to MongoDB Mapping Chart¶

In addition to the charts that follow, you might want to consider the Frequently Asked Questions section for a selection of common questions about MongoDB.

Executables¶

The following table presents the MySQL/Oracle executables and the corresponding MongoDB executables.