Professional Scala电子书

Table of Contents

Professional Scala

Why Subscribe?

PacktPub.com

Contributors

About the Authors

Preface

Who This Book Is For

What This Book Covers

What You Need for This Book

Conventions

Note

Tip

Installation and Setup

Installing IntelliJ IDE

Installing Scala plugin (make heading)

Reader Feedback

Customer Support

Downloading the Example Code

Errata

Piracy

Questions

Chapter 1. Setting up the Development Environment

Note

Simple Program

Definitions: Packages, Imports, and Objects

Object Definition

The main Method

Inside main

Structure of a Scala Project

Note

Note

Basic sbt Commands

Activity: Performing Basic Operations with sbt: Build, Run, Package

IDE

Activity: Loading and Running a Sample Project in the IDE

REPL

Obtaining the Time Request from Our Chatbot Program

Base Syntax

Note

Base Syntax for Definitions

Base Syntax for Expressions

Note

Unit Testing

Adding a Test to Our Project

Inside Tests

Running Tests for Chatbot

Note

Summary

Chapter 2. Basic Language Features

Objects, Classes, and Traits

Object

Note

Classes

Equality and Case Classes

Note

Note

Pattern Matching

Traits

Self-Types

Note

Note

Note

Special Classes

OO in Our Chatbot

Decoupling Logic and Environment

Note

Sealed Traits and Algebraic Datatypes

Note

Note

Function Calls

Syntax Goodies

Named Parameters

Default Parameters

Currying Forms (Multiple Argument Lists)

Special Magic Methods

Implementing + in CartesianPoint

Parameter-Passing Mode

By Value

By Name

By Need

Creating a Runnable Construction

Printing the log Argument to the Console and File

Summary

Chapter 3. Functions

Functions

Function Values

Function from an OO Point of View

Conversions

Defining and Measuring the Time of a Unit Function

Syntax Sugar in a Function Definition

Partial Functions

Exploring Pattern Matching

Binding a Sequence of Variables in the Pattern Matcher

Partial Functions in Practice

Note

Representing ChatbotMode as a Partial Function

Implementing RemindStore as a Set of Partial Functions

Note

Using Lifting for Conversations between Total and Partial Functions

Summary

Chapter 4. Scala Collections

Working with Lists

Constructing Lists

Note

Operations on Lists

Note

Pattern Matching on Lists

First-Order Methods on List

Appending and Concatenation

Taking the Length of a List

Reversing a List

Prefixes and Suffixes

Element Selection

Display

Note

Activity: Creating a New Mode for Chatbot Using Lists

Abstracting on Sequences

The Traversable Trait

Note

Note

Iterators

Streams

Activity: Implementing Fibonacci Series Using Streams and Iterators

Other Collections

Sets

Tuples

Maps

Note

Mutable and Immutable Collections

Activity: Implementing the Tower of Hanoi Problem

Summary

Chapter 5. Scala Type System

Type Basics and Polymorphism

A Unified Type System

Parametric Polymorphism

Type Inference

Parameterized Types

Bounds

Existential Types

Activity: Generalizing the Implementation of the Binary Tree

Note

Variance

Covariance

Contravariance

Invariance

Activity: Implementing Covariance and the Database for Tools

Advanced Types

Abstract Type Members

Structural Types

Option

Higher Kind Types

Type Erasure

Activity: Finding an Element Based on a Given Predicate

Summary

Chapter 6. Implicits

Implicit Parameters and Implicit Conversions

Implicit Parameters

Implicit Conversions

Note

Implicit Resolution

Note

Activity: Creation of Extension Methods

Ad Hoc Polymorphism and Type Classes

Types of Polymorphism

Type Classes

Context Bounds and Implicitly

Type Classes in the Standard Library

Note

Activity: Implementing Type Classes to Support Conversion

Summary

Chapter 7. Functional Idioms

Introduction to Functional Programming Concepts

Pure Functions

Immutability

Implementing the standard library

Higher-Order Functions

Functional Design Patterns

Note

Note

Monoids

Note

Using Monoids to Write Polymorphic Functions

Functor

Note

Note

Monads

Note

Note

Popular Libraries

Validating Data Using Cats

Note

Prerequisites for Using Cats

Introduction to Cats

Validating Data

Validating Using Validated

Communicating with Databases Using Doobie

Prerequisites for Doobie

Doobie

ConnectionIO

Transactor

Selecting Rows

Querying Using Parameters

Note

Deleting, Inserting, and Updating Rows

A Complete Example

Activity: Adding Priority to the Todo List

Summary

Chapter 8. Domain Specific Languages

DSLs and Types of DSLs

External DSLs

Note

Internal DSLs

ScalaTest – A Popular DSL

Note

Adding ScalaTest to Your Project

Note

Overview of ScalaTest Styles

Activity: Implementing ScalaTest Styles

Language Features for Writing DSLs

Flexible Syntax for Method Invocation

By-Name Parameters

Note

Extension Methods and Value Classes

Writing a Small DSL

Modeling Test Cases

DSL for TestCase

Activity: Creating a DSL to Specify Assertions

Note

Beyond This Book

Various Scala Libraries

Akka

Note

Note

Note

Apache Spark

Note

Shapeless

Uncovered Language Features

Macros

Note

Def Macros

Implicit Macros

Quasiquotes

Reflection

Note

Resources to Keep You Updated

Scala Improvement Process

Note

Scala Times

Note

Summary

Index

A

B

C

D

E

F

H

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L

M

N

O

P

Q

R

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T

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