Programming Crystal

Table of contents

1.  Preface
   1. Who This Book Is For
   2. What’s in This Book
   3. How to Read This Book
   4. Conventions Used in This Book
   5. Web Resources and Feedback
   6. Downloading Sample Code
   7. Acknowledgments
2. Part I. Getting Started
   1. 1. Diving into Crystal
      1. A Programming Language for Humans and Computers
      2. Slick As Ruby, But Way Faster
      3. Almost As Fast As C
      4. Speeding Up the Web
      5. Talking to Databases
      6. More Safety Through Types
      7. No to the Billion-Dollar Mistake
      8. Batteries Included
      9. Putting Crystal to Good Use
      10. A Company’s Story Crystallized: Red Panthers
      11. Wrapping Up
   2. 2. Crystal Foundations
      1. Using Basic Variables and Types
      2. Variable Operations
      3. Structuring Data with Container Types
      4. Controlling the Flow
      5. Using Methods
      6. Organizing Code in Classes and Modules
      7. Executing Code Concurrently Through Fibers
      8. A Company’s Story Crystallized: Dev Demand
      9. Wrapping Up
3. Part II. Building Blocks
   1. 3. Typing Variables and Controlling the Flow
      1. Converting Data Between Types
      2. Getting Input
      3. Putting It Together—Converting Currencies 1
      4. Exception Handling for Faulty Input
      5. Chaining Methods
      6. Getting Input from Command-Line Arguments
      7. Using String Methods
      8. Using Symbols as Identifiers
      9. Using Enums
      10. Using Regular Expressions
      11. Putting It Together—Converting Currencies 2
      12. Beyond Hashes and Arrays: More Composite Types
      13. Nilable Types
      14. Controlling the Flow and Types
      15. A Company’s Story Crystallized: Linkfeed
      16. Wrapping Up
   2. 4. Organizing Code in Methods and Procs
      1. Passing Arguments
      2. Returning Values
      3. Working with Yield, Procs, and Blocks
      4. Overloading and Multiple Dispatch
      5. Using a Shorter Syntax for Exception Handling
      6. Using Recursive Methods
      7. A Company’s Story Crystallized: Duo Design
      8. Wrapping Up
   3. 5. Using Classes and Structs
      1. Converting a Ruby Class to Crystal
      2. Structuring a Class
      3. Applying Inheritance
      4. Controlling Visibility
      5. Working with Structs
      6. Viewing the Type Hierarchy
      7. Some Nice Tricks
      8. A Company’s Story Crystallized: LI-COR Biosciences
      9. Wrapping Up
   4. 6. Working with Modules
      1. Combining Files with Require
      2. Using Modules as Namespaces
      3. Letting Modules Extend Themselves
      4. Mixing in Modules
      5. How the Compiler Finds Methods
      6. Applying Built-In Modules
      7. A Company’s Story Crystallized: Diploid
      8. Wrapping Up
   5. 7. Managing Projects
      1. Creating a Shard
      2. Formatting Code
      3. Documenting a Project
      4. Writing Tests with Spec
      5. Using External Libraries
      6. Benchmarking Your Code
      7. Deploying a Crystal App
      8. A Company’s Story Crystallized: Diploid—Part 2
      9. Wrapping Up
4. Part III. Advanced Crystal
   1. 8. Advanced Features
      1. DRY Your Code with Macros
      2. Low-Level Programming and C Bindings
      3. Creating Concurrent Code
      4. Accessing Databases
      5. A Company’s Story Crystallized: NeuraLegion
      6. Wrapping Up
   2. 9. Using Web Frameworks and Shards
      1. Build Web Applications with the Kemal and Amber Frameworks
      2. A Brief Tour of the Shard Ecosystem
      3. A Company’s Story Crystallized: Kemal in Production
      4. Wrapping Up and Afterword
5. Part IV. Appendices
   1. A1. Setting Up a Crystal Environment
      1. Working with Crystal Online
      2. Installing Crystal on Your Machine
      3. Compiling Code
      4. Using Editors and IDEs
      5. Working with Crystal Playground
      6. Using Crystal Documentation
      7. Wrapping Up
   2. A2. Porting Ruby Code to Crystal
      1. Ruby Extensions in Crystal
   3. A3. Your Turn Answers
      1. Chapter 2: Crystal Foundations
      2. Chapter 3: Typing Variables and Controlling the Flow
      3. Chapter 4: Organizing Code in Methods and Procs
      4. Chapter 5: Using Classes and Structs
      5. Chapter 6: Working with Modules
      6. Chapter 7: Managing Projects
      7. Chapter 8: Advanced Features
      8. Chapter 9: Web Frameworks and the Shard Ecosystem
      9. Appendix 1: Setting Up a Crystal Environment