List of Listings

Chapter 1. Introduction to Clojure

Listing 1.1. A small program written in our fictitious XML-based language

Listing 1.2. A slightly less verbose version of the same program

Listing 1.3. Typical duplication in Java code

Listing 1.4. The same code in Clojure, written as is

Listing 1.5. Removing duplication via a domain-specific macro

Listing 1.6. Typical usage of higher-order functions

Listing 1.7. Clojure’s STM in action

Chapter 3. Building blocks of Clojure

Listing 3.1. Mutually recursive functions that can blow the stack

Listing 3.2. Mutually recursive functions that can be called with trampoline

Listing 3.3. Function composition using higher-order functions

Listing 3.4. Listing 3.4 Dynamic scope in action

Listing 3.5. A higher-order function for aspect-oriented logging

Listing 3.6. Using external libraries by calling use

Listing 3.7. Using external libraries by calling require

Chapter 4. Polymorphism with multimethods

Listing 4.1. Implementing the Redis protocol using multimethods

Chapter 5. Clojure and Java interop

Listing 5.1. An abstract Java class that will be used to illustrate gen-class

Listing 5.2. gen-class generates a Java class to reference AbstractJavaClass

Chapter 8. Test-driven development and more

Listing 8.1. Example code that fetches and filters expenses from a data store

Listing 8.2. Simple stubbing and mocking functionality for Clojure tests

Chapter 9. Data storage with Clojure

Listing 9.1. The init-model macro from clj-record.core

Listing 9.2. Contents of a sample hbase-site.xml for a standalone HBase system

Listing 9.3. Transforming Clojure maps into ones suitable for insertion into HBase rows

Listing 9.4. Inserting a Clojure map into an HBase row

Listing 9.5. Reading the flattened map back out from HBase

Listing 9.6. Namespace containing functions exposed to users of this library

Listing 9.7. Namespace containing functions to persist and read back maps from Redis

Chapter 10. Clojure and the web

Listing 10.1. A simple way to expose Clojure functions as web services

Listing 10.2. Extending our basic web service framework to support JSONP callbacks

Listing 10.3. Changes needed to support simple cookie handling

Chapter 11. Scaling through messaging

Listing 11.1. A simple messaging-based distributed-computing framework for Clojure

Listing 11.2. Distributed worker processes to handle worker requests

Listing 11.3. The new multicast-capable messaging code

Listing 11.4. A new implementation of the framework for fire and forget and multicasting

Chapter 12. Data processing with Clojure

Listing 12.1. Computing the frequency of words in given text

Listing 12.2. General map/reduce extracted out of the word-count example

Listing 12.3. Using map/reduce to calculate average number of words in each line

Listing 12.4. The request-seq abstraction for Ruby on Rails log files

Listing 12.5. Analyzing Rails log to compute frequencies of controller calls

Listing 12.6. session-seq built on top of request-seq

Listing 12.7. Computing the average length of sessions from a Rails log file

Listing 12.8. The core namespace for our master/slave batch-processing framework

Listing 12.9. The status namespace for our master/slave batch-processing framework

Chapter 13. More on functional programming

Listing 13.1. A simple object system for Clojure

Chapter 14. Protocols, records, and types

Listing 14.1. Skeleton Java class implementing the concept of the expense item

Listing 14.2. Implementing modus operandi on top of multimethods

Listing 14.3. The expense namespace using the modus operandi multimethod syntax

Listing 14.4. Testing the implementation of modus operandi calculating expense totals

Listing 14.5. The expense namespace using a Clojure protocol

Listing 14.6. The expense namespace using a Clojure protocol and defrecord

Listing 14.7. The expense namespace with defrecord and inline protocol

Chapter 15. More macros and DSLs

Listing 15.1. A general rotation cipher system to implement things like ROT13

Listing 15.2. Basic functions to handle session persistence in Redis

Listing 15.3. The dsl-store namespace for storing the rules as anonymous functions

Listing 15.4. The segmentation DSL defined using a simple macro

Listing 15.5. The simple DSL execution engine to classify users into segments