Intro
Table of Contents
About the Author
About the Technical Reviewer
Introduction
Chapter 1: ReScript Basics
Expressions, Values, and Side Effects
Compile Time and Runtime
Types, Typechecking, and Type Inference
Primitive Types and Operators
Integer and Float
Boolean
String
Unit
Printing and Debugging
Bindings
Mutation and Refs
Blocks
Block Scoping
Conditionals
Switches
Loops
Putting It All Together
Final Thoughts
Chapter 2: Functions
Defining and Using Functions
Type Annotations

Using Standard Library Functions and Opening Modules
Higher-Order Functions
Piping
Labeled and Optional Parameters
Currying and Partial Application
Polymorphic Functions
Pure Functions
Ignoring Return Values
Recursion
Syntax
How to Use Recursion
Final Thoughts
Chapter 3: Composite Data Types
Tuples
Creating Tuples
Accessing Tuples
Pattern Matching with Tuples
Variants
Declaring and Constructing Variants
Pattern Matching with Variants
Exhaustiveness
Complex Patterns
Variants with Data
Recursive Data Types
Options

Pattern Matching Options
Exceptions and Error Handling
Raising Exceptions
Catching Exceptions
Custom Exceptions
Another Way to Handle Errors: Result
Result in Action
Defining Errors for Results
Composing Results
Final Thoughts
Chapter 4: Records and Objects
Records
Declaring and Creating Records
Nominal Typing
Accessing Record Fields
Updating Records
Mutable Fields
Optional Fields
Destructuring Records
Pattern Matching with Records
Records and Variants
Printing Records
Records and JSON
Serialization
Deserialization
Objects

Declaring and Creating Objects
Accessing Object Fields
Structural Typing
Mutating Objects
Printing Objects
Objects and JSON
Serializing Objects
Deserializing Objects
Objects vs. Records
Chapter 5: Lists and Arrays
Arrays
Array Standard Library
Note on Accessing Arrays
Higher-Order Functions for Arrays
Map
Filter
Reduce
Composing Higher-Order Functions
Higher-Order Functions in Action
Generalizing Higher-Order Functions
Lists
Building a List
Immutability and Lists
Pattern Matching with List
Higher-Order Functions with Lists

Drawbacks of Lists
Use Cases for Immutable Collections
Lists vs. Arrays
Final Thoughts
Chapter 6: Collections
Immutable Collections
Immutable Sets
Creating a Set
Updating a Set
Common Set Operations
Immutable Maps
Creating a Map
Updating a Map
Accessing a Map
Using Collections: Luggage Example Revisited
Advanced Topic: Generic Collections
Mutable Collections
Mutable Stack
Mutable Queue
Mutable Set and Mutable Map
Mutable Map Example
Hash Set and Hash Map
Creating a Hash Set/Hash Map
Accessing Hash Maps
Hash Map Example