book

Get Programming with Scala

Name: Get Programming with Scala
Author: Daniela Sfregola
ISBN: 9781617295270

by Daniela Sfregola

September 2021

Beginner

560 pages

10h 49m

English

Manning Publications

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inside front cover
Get Programming with Scala
Copyright
dedication
Contents
front matter
PrefaceAcknowledgmentsAbout this bookWho should read this bookHow this book is organized: A roadmapAbout the codeliveBook discussion forumAbout the author
Unit 0. Hello Scala!
1 Why Scala?
1.1 Why Scala?1.2 Scala and the JVM1.3 Scala’s key featuresSummary
2 The Scala environment
2.1 The REPL installation2.2 The REPL commands2.3 The REPL code evaluation2.4 Other development tools2.4.1 Git installation2.4.2 Docker installationSummary
3 Scala Build Tool (sbt)
3.1 Why sbt?3.2 sbt installation3.3 sbt commands3.4 Your first sbt project3.5 sbt project structureSummary

Unit 1. The Basics
4 Values and variables
4.1 Values4.2 VariablesSummaryAnswers to quick checks
5 Conditional constructs and loops
5.1 If-else construct5.2 While loop5.3 For loopSummaryAnswers to quick checks
6 Function as the most fundamental block of code
6.1 FunctionsSummaryAnswers to quick checks
7 Classes and subclasses to represent the world
7.1 Class7.2 Subclass7.3 Abstract classSummaryAnswers to quick checks
8 The vending machine
8.1 Setting up the vending machine8.1.1 The VendingMachine class and its APIs8.1.2 The vending machine and its operations8.1.3 Let’s try it out8.2 Possible improvements to our solutionSummary
Unit 2. Object-oriented fundamentals
9 Import and create packages
9.1 Import an existing package9.2 Create a packageSummaryAnswers to quick checks
10 Scope your code with access modifiers
10.1 Public, the default access modifier10.2 Private10.3 Protected10.4 Which access level to use?SummaryAnswers to quick checks
11 Singleton objects
11.1 Object11.2 Executable object11.3 Companion object11.4 The apply methodSummaryAnswers to quick checks
12 Traits as interfaces
12.1 Defining traits12.2 Extending traits12.3 Sealed traits12.4 Enumeration in Scala 3SummaryAnswers to quick checks
13 What time is it?
13.1 What time is it?13.1.1 sbt project setup13.1.2 The business logic layer13.1.3 The TimeApp executable object13.1.4 Let’s try it out!13.2 Possible improvements to our solutionSummary
Unit 3. HTTP server
14 Pattern matching
14.1 If-else construct vs. pattern matching14.2 Sealed pattern matchingSummaryAnswers to quick checks
15 Anonymous functions
15.1 Function vs. anonymous function15.2 Concise notation for anonymous functionsSummaryAnswers to quick checks
16 Partial functions
16.1 Partial functions16.1.1 Implementing a partial function16.1.2 Function composition16.2 Use case: Exception handlingSummaryAnswers to quick checks
17 HTTP API with http4s
17.1 An overview of http4s17.2 A ping server using http4s17.2.1 Initial setup17.2.2 Implementing the API17.2.3 Building a server17.2.4 Let’s try it out!SummaryAnswers to quick checks
18 The time HTTP server
18.1 What time is it?18.1.1 Setting your sbt project up18.1.2 The TimePrinter class18.1.3 The API routes18.1.4 The HTTP server18.1.5 Let’s try it out!18.2 Possible improvements to our solutionSummary
Unit 4. Immutable data and structures
19 Case classes to structure your data
19.1 Case class19.2 Pattern matching and case classes19.3 Case objectSummaryAnswers to quick checks
20 Higher order functions
20.1 Functions as parameters20.2 Functions as return valuesSummaryAnswers to quick checks
21 What is purity?
21.1 A definition of purity21.2 Differentiating between pure and impure functionsSummaryAnswers to quick checks
22 Option
22.1 Why Option?22.2 Creating an Option22.3 Pattern matching on OptionSummaryAnswers to quick checks
23 Working with Option: map and flatMap
23.1 Transforming an Option23.1.1 The map function23.1.2 The flatten function23.1.3 The flatMap functionSummaryAnswers to quick checks
24 Working with Option: For-comprehension
24.1 For-comprehension on Option24.1.1 For-comprehension as syntactic sugar for nested map and flatMap calls24.1.2 Filtering values within for-comprehension24.2 Other operations on OptionSummaryAnswers to quick checks
25 Tuple and unapply
25.1 Tuples25.2 Implementing the unapply methodSummaryAnswers to quick checks
26 Rock, Paper, Scissors, Lizard, Spock!
26.1 Implementing Rock, Paper, Scissors, Lizard, Spock!26.1.1 sbt project setup and packages26.1.2 Defining a symbol26.1.3 Representing a player26.1.4 Defining a game26.1.5 The API routes26.1.6 The HTTP server26.1.7 Let’s try it out!26.2 Possible improvements to our solutionSummary
Unit 5. List
27 List
27.1 Creating a list27.2 Adding elements to a list27.3 Pattern matching on a listSummaryAnswers to quick checks
28 Working with List: map and flatMap
28.1 The map, flatten, and flatMap operations28.1.1 The map function28.1.2 The flatten function28.1.3 The flatMap function28.2 For-comprehensionSummaryAnswers to quick checks
29 Working with List: Properties
29.1 Size of a list29.2 Properties of the elements in a listSummaryAnswers to quick checks
30 Working with List: Element selection
30.1 Selecting an element by its position30.2 Finding an element with given features30.3 Picking the minimum or maximum itemSummaryAnswers to quick checks
31 Working with List: Filtering
31.1 Dropping and taking elements31.2 Filtering Items of a list31.3 Removing duplicatesSummaryAnswers to quick checks
32 Working with List: Sorting and other operations
32.1 Sorting elements32.2 Converting a list to a string32.3 Sum elements of numerical sequences32.4 Grouping elements by featureSummaryAnswers to quick checks
33 The movies dataset
33.1 Download the base project33.2 Parsing a movie entity33.3 Printing query results33.4 Querying the movie data setSummary
Unit 6. Other collections and error handling
34 Set
34.1 Creating a set34.2 Adding and removing elements34.3 The map, flatten, and flatMap operations34.3.1 The map function34.3.2 The flatten function34.3.3 The flatMap function34.4 For-comprehensionSummaryAnswers to quick checks
35 Working with Set
35.1 The Union, Intersection, and Difference operations35.2 Other operations on SetSummaryAnswers to quick checks
36 Map
36.1 Creating Map36.2 Adding and removing elements36.3 Merge and remove multiple entries36.4 The map and flatMap operations36.4.1 The map function36.4.2 The flatMap function36.5 For-comprehensionSummaryAnswers to quick checks
37 Working with Map
37.1 Retrieving a value for a given key37.2 Getting all keys and values37.3 Other operations on MapSummaryAnswers to quick checks
38 Either
38.1 Why Either?38.2 Creating an Either38.3 Pattern matching on Either38.4 The map and flatMap operations38.4.1 The map function38.4.2 The flatMap function38.5 For-comprehensionSummaryAnswers to quick checks
39 Working with Either
39.1 Retrieving an Either value39.2 Properties of an Either valueSummaryAnswers to quick checks
40 Error handling with Try
40.1 Creating a Try40.2 Pattern matching on Try40.3 The map, flatten, and flatMap operations40.3.1 The map function40.3.2 The flatten function40.3.3 The flatMap function40.4 For-comprehension40.5 Other operations on TrySummaryAnswers to quick checks
41 The library application
41.1 Download the base project41.2 Parsing a book entity41.3 The business logic layer41.3.1 Performing a book search41.3.2 Reserving a book41.3.3 Returning a book41.4 Let’s give it a try!41.5 Possible improvements to our solutionSummary
Unit 7. Concurrency
42 Implicit and type classes
42.1 Implicit parameters and values42.2 Implicit resolution42.3 Type classesSummaryAnswers to quick checks
43 Future
43.1 Why Future?43.2 Creating an instance of Future43.3 Processing Future on completionSummaryAnswers to quick checks
44 Working with Future: map and flatMap
44.1 The map, flatten, and flatMap operations44.1.1 The map function44.1.2 The flatten function44.1.3 The flatMap functionSummaryAnswers to quick checks
45 Working with Future: For-comprehension and other operations
45.1 For-comprehension45.2 Retrieving the first Future to completeSummaryAnswers to quick checks
46 Database queries with Quill
46.1 Project setup46.1.1 Download the base project46.1.2 Starting the PostgreSQL server46.2 Connecting to the PostgreSQL server46.3 Executing queries46.4 Running generated queriesSummaryAnswers to quick checks
47 The quiz application: Part 1
47.1 Download the base project47.2 Health check queries47.3 Category queries47.4 Question and answer queries47.5 Let’s give it a try!Summary
Unit 8. JSON (de)serialization
48 JSON (de)serialization with circe
48.1 Project setup48.2 JSON serialization: From instance to JSON48.3 JSON deserialization: From JSON to instanceSummaryAnswers to quick checks
49 Lazy evaluation
49.1 By-name parameters49.2 Lazy valuesSummaryAnswers to quick checks
50 The IO type
50.1 Why IO?50.2 Project setup50.3 Synchronous side effect50.4 Asynchronous side effectSummaryAnswers to quick checks
51 Working with the IO type
51.1 The map and flatMap operations51.1.1 The map function51.1.2 The flatMap function51.2 For-comprehension51.3 Parallel executionSummaryAnswers to quick checks
52 Testing with ScalaTest
52.1 Project setup52.2 Your first test52.3 Asynchronous testingSummaryAnswers to quick checks
53 The quiz application: Part 2
53.1 Download the base project53.2 Generic endpoints53.3 Displaying the available categories53.4 Creating a quiz53.5 Answering a quiz53.6 The HTTP server53.7 Writing tests53.8 Let’s give it a try!Summary
Index
inside back cover

Content preview from Get Programming with Scala

53 The quiz application: Part 2

In this capstone, you will

Lazily evaluate side effects using the type IO
Define an HTTP API to send and receive requests using http4s
Serialize and deserialize HTTP responses in JSON format using circe
Write tests to assert that your business logic is correct

In this capstone, you’ll complete the quiz application you started in unit 7 by defining its service and API layers. In particular, you’ll implement a server that offers its users an HTTP API to perform the following operations:

Inform about the status of your application.
Display a list of categories a user can choose.
Generate a quiz by randomly choosing 10 questions for a given category.
Calculate the quiz score based on the received answers. ...

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by Daniela Sfregola

53 The quiz application: Part 2

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