Starting with Clojure

setup a clojure project
-------------------------
* Use `mvn archetype:generate` to create a project. (archetype id 845 for sample clojure project)

* add the nrepl dependency 
  <dependency>
    <groupId>org.clojure</groupId>
    <artifactId>tools.nrepl</artifactId>
    <version>0.2.0-beta9</version>
  </dependency>
 [https://github.com/talios/clojure-maven-plugin]
(to upgrade the version add the following in to the pom.xml
   <repository>
     <id>clojars.org</id>
     <url>http://clojars.org/repo</url>
   </repository>
)

* make sure  the clojure maven plug-in version is above 1.3.14

* adding support for auto complete
  <dependency>
     <groupId>clojure-complete</groupId>
     <artifactId>clojure-complete</artifactId>
     <version>0.2.3</version>
     <scope>test</scope>
        <exclusions>
             <exclusion>
                 <artifactId>clojure</artifactId>
                  <groupId>org.clojure</groupId>
              </exclusion>
         </exclusions>
  </dependency> 


setup nrepl in emacs 
----------------------
* Install emacs.

* add the following to ~/.emacs.d/init.el
     (require 'package)
     (add-to-list 'package-archives
                  '("marmalade" . "http://marmalade-repo.org/packages/"))
     (package-initialize)

* load it with `M-x eval-buffer` (M-x: meta+x i.e alt+x)
* install nrepl with, `M-x package-install [RET] nrepl [RET]` 
                            (RET-enter) [https://github.com/clojure-emacs/nrepl.el]

* toenable auto complete and paredit, add the following entry to the ~/.emacs.d/init.el
========================================================================================
(defvar my-packages '(starter-kit
                      starter-kit-lisp
                      starter-kit-bindings
                      starter-kit-eshell
                      clojure-mode
                      clojure-test-mode
                      auto-complete
                      nrepl
                      ac-nrepl))

(dolist (p my-packages)
  (when (not (package-installed-p p))
    (package-install p)))

(add-to-list 'load-path "~/emacs.d/paredit/paredit.el")

(add-hook 'nrepl-repl-mode-hook 'paredit-mode)

(require 'ac-nrepl)
(add-hook 'nrepl-mode-hook 'ac-nrepl-setup)
(add-hook 'nrepl-interaction-mode-hook 'ac-nrepl-setup)
(eval-after-load "auto-complete"
  '(add-to-list 'ac-modes 'nrepl-mode))


(defun set-auto-complete-as-completion-at-point-function ()
(setq completion-at-point-functions '(auto-complete)))
(add-hook 'auto-complete-mode-hook 'set-auto-complete-as-completion-at-point-function)

(add-hook 'nrepl-mode-hook 'set-auto-complete-as-completion-at-point-function)
(add-hook 'nrepl-interaction-mode-hook 'set-auto-complete-as-completion-at-point-function)

(define-key nrepl-interaction-mode-map (kbd "C-c C-d") 'ac-nrepl-popup-doc)

(setq initial-scratch-message "")
======================================================================================== 
* create the ~/emacs.d/paredit/paredit.el file with following content mention in the url
  http://mumble.net/~campbell/emacs/paredit.el


Connect to nrepl 
-----------------
*execute the following command in the project root
   `mvn clojure:nrepl`

*connect to nrepl in emacs by
   `M-x nrepl`
    host- 127.0.0.1, port-4005

* enable `paredit-mode` and `auto-complete-mode` 
  (M-x paredit-mode [RET]) (M-x auto-complete-mode [RET])


samples
------------------------
> (import 'java.util.Random)
[in clojure code use `:import java.util.Random`]

> (.nextInt (new Random)) or (.nextInt (Random.)) where the `.` in the Random. is a reader macro