Table of Contents

Copyright

Brief Table of Contents

Table of Contents

Praise for the First Edition

Preface to the Second Edition

Preface to the First Edition

Acknowledgments

About this Book

Chapter 1. Introducing Clojure

1.1. Clojure: What and why?

1.1.1. Clojure: A modern Lisp

1.1.2. Clojure: Pragmatic functional programming

1.1.3. Clojure on the JVM

1.2. Language basics

1.2.1. Lisp syntax

1.2.2. Parentheses

1.3. Host interoperation: A JVM crash course

1.3.1. Java types, classes, and objects

1.3.2. The dot and new operators

1.3.3. Threads and concurrency

1.4. Summary

Chapter 2. Clojure elements: Data structures and functions

2.1. Coding at the REPL

2.1.1. Clojure REPL

2.1.2. “Hello, world!”

2.1.3. Looking up documentation using doc, find-doc, and apropos

2.1.4. A few more points on Clojure syntax

2.2. Clojure data structures

2.2.1. nil, truth, and falsehood

2.2.2. Characters and strings

2.2.3. Clojure numbers

2.2.4. Symbols and keywords

2.2.5. Lists

2.2.6. Vectors

2.2.7. Maps

2.2.8. Sequences

2.3. Program structure

2.3.1. Functions

2.3.2. The let form

2.3.3. Side effects with do

2.3.4. Reader macros

2.4. Program flow

2.4.1. Conditionals

2.4.2. Logical functions

2.4.3. Functional iteration

2.4.4. Threading macros

2.5. Summary

Chapter 3. Building blocks of Clojure

3.1. Metadata

3.1.1. Java type hints

3.1.2. Java primitive and array types

3.2. Java exceptions: try and throw

3.3. Functions

3.3.1. Defining functions

3.3.2. Calling functions

3.3.3. Higher-order functions

3.3.4. Writing higher-order functions

3.3.5. Anonymous functions

3.3.6. Keywords and symbols

3.4. Scope

3.4.1. Vars and binding

3.4.2. The let form revisited

3.4.3. Lexical closures

3.5. Namespaces

3.5.1. ns macro

3.5.2. Working with namespaces

3.6. Destructuring

3.6.1. Vector bindings

3.6.2. Map bindings

3.7. Reader literals

3.8. Summary

Chapter 4. Multimethod polymorphism

4.1. Polymorphism and its types

4.1.1. Parametric polymorphism

4.1.2. Ad hoc polymorphism

4.1.3. Subtype polymorphism

4.2. Polymorphism using multimethods

4.2.1. Life without multimethods

4.2.2. Ad hoc polymorphism using multimethods

4.2.3. Multiple dispatch

4.2.4. Subtype polymorphism using multimethods

4.3. Summary

Chapter 5. Exploring Clojure and Java interop

5.1. Calling Java from Clojure

5.1.1. Importing Java classes into Clojure

5.1.2. Creating instances

5.1.3. Accessing methods and fields

5.1.4. Macros and the dot special form

5.1.5. Helpful Clojure macros for working with Java

5.1.6. Implementing interfaces and extending classes

5.2. Compiling Clojure code to Java bytecode

5.2.1. Example: A tale of two calculators

5.2.2. Creating Java classes and interfaces using gen-class and gen-interface

5.3. Calling Clojure from Java

5.4. Summary

Chapter 6. State and the concurrent world

6.1. The problem with state

6.1.1. Common problems with shared state

6.1.2. Traditional solution

6.2. Separating identities and values

6.2.1. Immutable values

6.2.2. Objects and time

6.2.3. Immutability and concurrency

6.3. Clojure’s way

6.3.1. Immutability and performance

6.3.2. Managed references

6.4. Refs

6.4.1. Creating refs

6.4.2. Mutating refs

6.4.3. Software transactional memory

6.5. Agents

6.5.1. Creating agents

6.5.2. Mutating agents

6.5.3. Working with agents

6.5.4. Side effects in STM transactions

6.6. Atoms

6.6.1. Creating atoms

6.6.2. Mutating atoms

6.7. Vars

6.7.1. Creating vars and root bindings

6.7.2. Var bindings

6.8. State and its unified access model

6.8.1. Creating

6.8.2. Reading

6.8.3. Mutation

6.8.4. Transactions

6.8.5. Watching for mutation

6.9. Deciding which reference type to use

6.10. Futures and promises

6.10.1. Futures

6.10.2. Promises

6.11. Summary

Chapter 7. Evolving Clojure through macros

7.1. Macro basics

7.1.1. Textual substitution

7.1.2. The unless example

7.1.3. Macro templates

7.1.4. Recap: Why macros?

7.2. Macros from within Clojure

7.2.1. comment

7.2.2. declare

7.2.3. defonce

7.2.4. and

7.2.5. time

7.3. Writing your own macros

7.3.1. infix

7.3.2. randomly

7.3.3. defwebmethod

7.3.4. defnn

7.3.5. assert-true

7.4. Summary

Chapter 8. More on functional programming

8.1. Using higher-order functions

8.1.1. Collecting results of functions

8.1.2. Reducing lists of things

8.1.3. Filtering lists of things

8.2. Partial application

8.2.1. Adapting functions

8.2.2. Defining functions

8.3. Closures

8.3.1. Free variables and closures

8.3.2. Delayed computation and closures

8.3.3. Closures and objects

8.3.4. An object system for Clojure

8.4. Summary

Chapter 9. Protocols, records, and types

9.1. The expression problem

9.1.1. Setting up the example scenario

9.1.2. A closer look at the expression problem and some potential solutions

9.1.3. Clojure’s multimethods solution

9.2. Examining the operations side of the expression problem

9.2.1. def-modus-operandi

9.2.2. detail-modus-operandi

9.2.3. Tracking your modus operandi

9.2.4. Error handling and trouble spots in this solution

9.3. Examining the data types side of the expression problem with protocols

9.3.1. defprotocol and extend-protocol

9.3.2. Defining data types with deftype, defrecord, and reify

9.4. Summary

Chapter 10. Test-driven development and more

10.1. Getting started with TDD: Manipulating dates in strings

10.1.1. First assertion

10.1.2. month-from and year-from

10.1.3. as-string

10.1.4. Incrementing and decrementing

10.1.5. Refactor mercilessly

10.2. Improving tests through mocking and stubbing

10.2.1. Example: Expense finders

10.2.2. Stubbing

10.2.3. Mocking

10.2.4. Mocks versus stubs

10.2.5. Managing stubbing and mocking state

10.3. Organizing tests

10.3.1. The testing macro

10.3.2. The are macro

10.4. Summary

Chapter 11. More macros and DSLs

11.1. A quick review of macros

11.2. Anaphoric macros

11.2.1. The anaphoric if

11.2.2. The thread-it macro

11.3. Shifting computation to compile time

11.3.1. Example: Rotation ciphers without macros

11.3.2. Making the compiler work harder

11.4. Macro-generating macros

11.4.1. Example template

11.4.2. Implementing make-synonym

11.4.3. Why macro-generating macros

11.5. Domain-specific languages

11.5.1. DSL-driven design

11.5.2. User classification

11.6. Summary

 Conclusion

Installing Clojure

A.1. Try Clojure

A.2. Clojure.jar

A.3. Leiningen

A.3.1. lein tasks

A.3.2. lein repl

A.3.3. Adding dependencies to a Leiningen project

Index

List of Figures

List of Tables

List of Listings