Usage:
java javelin.Core [OPTION] [ARGS...]
java -cp javelin.jar javelin.Core [OPTION] [ARGS...]
java -jar javelin.jar [OPTION] [ARGS...]

Options:
    FILE  run a script.
    -h    print this screen.
    -r    run a REPL.
    -v    print version.
Operation:
    Binds *command-line-args* to a list of strings containing command line args that appear after FILE.

Special forms:
 . and catch def defmacro do doseq finally fn if import let loop new or quasiquote quote recur reify set! try
Defined symbols:
 * *command-line-args* + - / < <= = == > >= apply eval filter fold gensym instance? list load-file load-string macroexpand map mod nil? not not= nth pr print println prn quot range read read-line read-string slurp spit str symbol type
Macros:
 defn dotimes when while

(println "Hello, World!")

(javax.swing.JOptionPane/showMessageDialog nil "Hello, World!") ; GUI Hello, World!

; end-of-line comment

' quote
` quasiquote
~ unquote
~@ unquote-splicing

> (map type '(3 3L 3.0 3e3 true false nil "string" #"regex" \a :a))
(java.lang.Integer java.lang.Long java.lang.Double java.lang.Double java.lang.Boolean java.lang.Boolean nil java.lang.String java.util.regex.Pattern java.lang.Character javelin.Keyword)

> (let (a 1, b 2) (+ a b)) ; , is whitespace. () and [] are interchangeable in special forms.
3
> (doseq (x '(1 2 3)) (print x))
123nil
; (try EXPR ... (catch CLASS VAR EXPR ...) ... (finally EXPR ...))
> (try (quot 1 0) (catch ArithmeticException e (println e) 3) (finally (println 4)))
java.lang.ArithmeticException: / by zero
4
3

> (. * call)
1

> (def t1 (new Thread (fn () (loop (i 1) (when (<= i 10) (print "" i) (recur (+ i 1)))))))
  (def t2 (new Thread (fn () (loop (i 11) (when (<= i 20) (print "" i) (recur (+ i 1)))))))
  (. t1 start) (. t2 start) (. t1 join) (. t2 join)
  111 12 2 13 3 14 4 15 5 16 6 17 7 18 8 19 9 20 10nil

> (def a (list 3 2 1))
(3 2 1)
> (. java.util.Collections sort a -)
nil
> a
(1 2 3)

> ((fn (x y) (+ x y)) 1 2)
3
> ((fn (x) (* x 2)) 3)
6
> (defn foo (x & more) (list x more)) ; variadic function
(fn (x & more) (list x more))
> (foo 1 2 3 4 5)
(1 (2 3 4 5))
> (defn sum (x y) (+ x y))
(fn (x y) (+ x y))
> (sum 1 2)
3
> (fold + '(1 2 3))
6
> (defn even? (x) (== 0 (mod x 2)))
(fn (x) (== 0 (mod x 2)))
> (even? 3)
false
> (even? 4)
true
> (apply + (list 1 2 3))
6
> (map (fn (x) (. Math sqrt x)) (list 1 2 3 4))
(1.0 1.4142135623730951 1.7320508075688772 2.0)
> (filter even? (list 1 2 3 4 5))
(2 4)
> (= "abc" "abc") ; Object.equals()
true
> (def x 1)
  ((fn (x) (println x) (set! x 3) (println x)) 4) ; lexical scoping
  x
4
3
1
> (defn adder (amount) (fn (x) (+ x amount))) ; lexical scoping
  (def add3 (adder 3))
  (add3 4)
7
> (symbol "a")
a

> (apply + (filter (fn (x) (or (== 0 (mod x 3)) (== 0 (mod x 5)))) (range 1 1000)))
233168

> (defn sum1 (n s) (if (< n 1) s (recur (- n 1) (+ s n))))
> (defn sum (n) (sum1 n 0))
> (defn sum-nonrecur (n) (if (< n 1) 0 (+ n (sum-nonrecur (- n 1)))))
> (sum 100)
5050
> (sum-nonrecur 100)
5050
> (sum 1000)
500500
> (sum-nonrecur 1000) ; stack overflow
Exception in thread "main" java.lang.StackOverflowError
> (loop (i 0) (when (< i 5) (print i) (recur (+ i 1))))
01234nil

> (. (list 2 4 6) get 1)
4
> ((list 2 4 6) 1) ; implicit indexing
4
> (. (list 1 2 3) size)
3

> (. java.lang.reflect.Array get (. "a b" split " ") 1)
"b"
> ((. "a b" split " ") 1) ; implicit indexing
"b"

> (defmacro infix (a op & more) `(~op ~a ~@more))
nil
> (infix 3 + 4)
7
> (infix 3 + 4 5)
12
> (macroexpand '(infix 3 + 4 5))
(+  3 4 5)
> (macroexpand '(while true (println 1)))
(loop () (if true (do (println 1) (recur))))

> (import java.util) ; java.lang is imported by default.
nil
> (import java.util.Date) ; Clojure syntax
java.util.Date
> (new Date) (Date.)
Tue Sep 22 14:33:28 KST 2015
Tue Sep 22 14:33:28 KST 2015
> (. Math random) (Math/random) ; class's static method.
0.4780254852371699
0.21577491460068765
> (. Math floor 1.5)
1.0
> (. "abc" length) (.length "abc") ; object's method
3
3
> (. true toString)
true
> (def i 3)
3
> (. i doubleValue)
3.0
> (. Math -PI) Math/PI ; get field
3.141592653589793
3.141592653589793
> (. javelin.Core -testField)
nil
> (set! (. javelin.Core -testField) 1) ; set field
  (. javelin.Core -testField)
1
> (set! javelin.Core/testField "abc")
  javelin.Core/testField
abc
> (. (new java.math.BigInteger "2") pow 100) ; 2 ^ 100
1267650600228229401496703205376

(import javax.swing java.awt java.awt.event)

(def frame (new JFrame))
(def button (new Button "Hello"))
(. button addActionListener
	(reify java.awt.event.ActionListener
	  (actionPerformed (this e)
		(. javax.swing.JOptionPane showMessageDialog nil (str "Hello, World!\nthis=" this "\ne=" e)))))
(. frame setDefaultCloseOperation (. JFrame -EXIT_ON_CLOSE))
(. frame add button (. BorderLayout -NORTH))
(. frame pack)
(. frame setVisible true)

(import (java.util Date))

(defn get-quote []
  (try
    (let [text (slurp "http://kosdb.koscom.co.kr/main/jisuticker.html" :encoding "euc-kr")
          m (. #"KOSPI200.*>(.+)</font>" matcher text)]
      (if (. m find) (. (. m group 1) replaceAll "&nbsp;" "") ""))
    (catch Exception e (println e))))

(loop []
  (println (new Date) ":" (get-quote))
  (. Thread sleep 2000)
  (recur))

public class Player {
    private int life;
    public int getLife() {
        return life;
    }
    public void setLife(int life) {
        this.life = life;
    }
}

public class InteropTest {
    public static Object testField;
    public static void main(String[] args) {
        Player pl = new Player();

        // Method 1: using class's field
        testField = pl;
        javelin.Core.load_string("(def pl (. InteropTest -testField))");
        javelin.Core.load_string("(. pl setLife 100)");
        System.out.println(javelin.Core.load_string("(. pl getLife)"));

        // Method 2: not using class's field, set variable to Java's local variable
        javelin.Core.set("p12", pl); // set
        Player pl2 = javelin.Core.get("pl2"); // get
        javelin.Core.load_string("(. pl2 setLife 200)");
        System.out.println(javelin.Core.load_string("(. pl2 getLife)"));
    }
}