Appeared in | 2007 |
Designed by | Rich Hickey |
Typing discipline | dynamic, strong |
Influenced by | Lisp, ML, Haskell, Erlang |
License | Eclipse Public License |
Website | http://clojure.org |
Let's start with quoting Rich Hickey's words from Clojure's website.
Clojure is a dynamic programming language that targets the Java Virtual Machine. It is designed to be a general-purpose language, combining the approachability and interactive development of a scripting language with an efficient and robust infrastructure for multithreaded programming. Clojure is a compiled language - it compiles directly to JVM bytecode, yet remains completely dynamic. Every feature supported by Clojure is supported at runtime. Clojure provides easy access to the Java frameworks, with optional type hints and type inference, to ensure that calls to Java can avoid reflection.
Clojure is a dialect of Lisp, and shares with Lisp the code-as-data philosophy and a powerful macro system. Clojure is predominantly a functional programming language, and features a rich set of immutable, persistent data structures. When mutable state is needed, Clojure offers a software transactional memory system and reactive Agent system that ensure clean, correct, multithreaded designs.
With our words,
- Among its alternatives, Clojure has one of the most complete concurrency frameworks (Refs, Agents, Atoms, and STM a.k.a. Software Transactional Memory) built into the programming language itself. Moreover, its immutable data structures and functional design plays an important role to back this design up.
- Seamless integration with Java world (where every Clojure function is Callable/Runable from Java side of view, and you can access Java variables/functions/classes/packages from Clojure with great ease) brings you the access to all available Java libraries in the wild.
- Builtin support for lazy evaluation shines with its ease of use and seamless integration into the language.
Reference Resources
- Official Clojure Reference (Recommended!)
- Clojure - Functional Programming for the JVM by R. Mark Volkmann (Recommended!)
- Clojure Programming at WikiBooks
- Learning Clojure at WikiBooks
Books
- Clojure Bookshelf: Books that influenced Clojure.
- Programming Clojure by Stuart Halloway.
- A Definitive Guide to Clojure by Luke VanderHart.
Other Resources
- Rich Hickey's On State and Identity article and related presentation at InfoQ entitled Persistent Data Structures and Managed References. (Recommended!)
- Rich Hickey's Clojure presentation at InfoQ.
- InfoQ interview with Rich Hickey about Clojure's Features and Implementation.
- Software Transactional Memory by R. Mark Volkmann (Recommended!)
- For packaging your Clojure applications see sample list of commands to build an executable JAR file for you Clojure application by Stephen C. Gilardi and clojure-maven-plugin project.
- Rich Hickey comments on Distributed Programming in Clojure.
Communities
- List of Clojure communities on Clojure website.
- Official Clojure Mailing List
- #clojure IRC channel at irc.freenode.net
- Planet Clojure
Libraries
- List of Clojure libraries on Clojure website.
- Extensions and enhancements to the Clojure libraries: clojure-contrib.
- Clojars is a dead easy community repository for open source Clojure libraries.
Editors
- For emacs, see swank-clojure (requires SLIME: The Superior Lisp Interaction Mode for Emacs) and clojure-mode projects. (See below editor tweaks for installation instructions.)
- For vim, see Meikel Brandmeyer's vimclojure project.
- NetBeans Clojure Plug-In: Enclojure.
- Eclipse Clojure Plug-In: Counterclockwise.
- IntelliJ Clojure Plug-In: clojure-intellij-plugin.
Editor Tweaks: Emacs
While you can reuse emacs lisp-mode (not SLIME!) tweaks mentioned in Common Lisp, for Clojure, we recommend you to install SLIME, clojure-mode and swank-clojure using ELPA package manager1 for emacs. (See ELPA website for installation instructions of packages.) After installating SLIME, clojure-mode, and swank-clojure via ELPA, just call clojure-install function from emacs.