ngscript

Introduction

A Javascript-like scripting language for JVM, with coroutine.

Quick Start

Clone project

git clone https://github.com/wssccc/ngscript.git

Run Rose-Render test

./gradlew run -Dexec.mainClass=org.ngscript.examples.RoseRender

Language References

Variable

Use var to explicitly define a variable

Examples

Define a variable

  var b;

Define a variable and initialize with a value

  var a = 1;

Inline definition

  for (var i = 0; i < 9; ++i) ...

Function

Named Function

Examples

   function func1 (param1, param2) {
       println(param1 + "," + param2);
   }

Named functions were registered in global scope.

Lambda

Examples

  (function (){
      println("hello");
  })();

  var f = function(){
      println("hello");
  };

  val f2 = (x, y) => { x + y; };

  val f3 = (x) => {
      return x + 1;
  };

  val f4 = (x ,y) => {
      return x + y;
  };

  println("call an arrow func");
  println(f3(1));

Java Method Reference

Examples

  //native Java ArrayList
  var array = new ArrayList();
  //add something
  array.add(1); array.add(2); array.add(3);
  //reference to method of a Java object
  var ref_get = array.get;
  //call the reference to get the element of index 1
  println(ref_get(1));

Go statement

Examples

  val f = function(arg) {
      println("in other routine " + arg);
  };

  go f(123);
  println("in main routine");

Object

ngscript object

Examples

Define a constructor function

  function One(name) {
      this.hello = function(){
          println("I'm " + name);
      };
  }

Create an object with the new operator

  var newone = new One("wssccc");
  newone.hello();

Java Object

Examples

Create an ArrayList

  var arraylist = new ArrayList();
  arraylist.add(1);
  arraylist.add(2);
  println(arraylist.toString());
  arraylist.remove(0);
  println(arraylist.toString());

Import

The same as import statement in Java

java.lang.* and java.util.* classes were imported by default.

typeof

Get string representation of the type of an object

Examples

  println(typeof println);
  var a = 1;
  println(typeof a);
  println(typeof println);

println

Print a line.

eval

  println(eval("15+20"));

Error Handling

Examples

  try {
          println("will throw excepton");
          throw "exception";
  } catch (e) {
          println(e.toString());
  }

Coroutine

Examples

  function f(a,b) {
          println("first = " + a);
          // return 1 and switch to caller
          yield(1); 
          // resume here
          println("second = " + b);
  }

  // create coroutine
  var co = new Coroutine(f, "p1", "p2"); 

  println("coroutine status=" + co.status());
  // call resume() to run
  println("resume 1 = " + co.resume());
  println("coroutine status=" + co.status());
  // call resume() to run to the end of function f
  println("resume 2 = " + co.resume());
  println("coroutine status=" + co.status());

  try {
          println("resume 3:");
          println(co.resume());
  } catch(e) {
          println("could not resume, status=" + co.status());
  }