How to use ReoScript to run JavaScript

Run JavaScript in .Net program

Download ReoScript binary library or build source code. The following two DLLs must be added into target project.

• Antlr3.Runtime.dll
• Unvell.ReoScript.dll

And import this namespace:

using Unvell.ReoScript;

There is a main class named ScriptRunningMachine available in ReoScript, you need use it to load/run script.

ScriptRunningMachine srm = new ScriptRunningMachine();

Now there is a script run-time machine and default context was be created. (Learn more about ScriptRunningMachine)

srm.Run("alert('hello world!');");

A message box with text 'hello world' will be display.

Difference between JavaScript and ReoScript

There is a brief of what the different between ReoScript and JavaScript:

1. ReoScript requests more stricter syntax check. Except block (non-anonymous function, if, for, switch and etc.), all Sentences in ReoScript should be end with semicolons.

    function count() { return 10 }         // error
    function count() { return 10; }        // ok
   
    var a = function() { return 10; }      // error
    var a = function() { return 10; };     // ok
   

   See about Language Specification.

2. GlobalObject named window in JavaScript but named script in ReoScript.

    window.hello = function() { };         // JavaScript
    script.hello = function() { };         // ReoScript
   

   See about GlobalObject.

3. Iteration for...in works on Array will return element self.

    var arr = [1, 5, 'ok', false];
    for(e in arr) console.log(e);
   

   The difference is JavaScript returns index but ReoScript returns element self as below:

    JavaScript      ReoScript
    0               1
    1               5
    2               ok
    3               false
   

   See about Enumerator.

4. setTimeout and setInterval in ReoScript supports to pass arguments.

   If you use setTimeout to call a function, you may pass arguments to the function as below:

    function run(obj) {
        console.log('Object is ' + obj.name);
    }
   
    setTimeout(run, 1000, {name: 'obj1'});
   

   See about Enhanced Async-Calling.

5. Regular Expressions currently not supported. However, you can make an extension such as extended native function to support .Net Regular Expressions for script. (See How to extend function for script)

Merge script files

In HTML and JavaScript we could use <script> tag to import another script file into current page. Once a script file was be imported, all variables and functions defined in that file will be available for current page. It is also possible to implement same effect in ReoScript by using import keyword.

Script File: common.rs

var MAX_PATH = 256;                           // global variable for all script files

function get_extension(filepath) {
   var index = filepath.lastIndexOf('.');
   return filePath.substr(index + 1);
}

Script File: main.rs

import "common.rs";

var ext = get_extension('sample.txt');
console.log('extension is ' + ext);

The result is:

extension is txt

Run ReoScript in Windows Console

You may also run a file that contains whole ReoScript in Windows Console by ReoScript Runner. It was available since ReoScript 1.2. (See ReoScript Runner)