Mascara JavaScript compiler Blog

Finally, Mascara beta 1 has been released. Download here.

What does beta mean? It means that the program is fully functional and useful, but may still contain bugs. You are invited to download and try it out, and report any bugs you find.

It is not a complete, conformant implementation of ECMAScript 4/Harmony. The official ECMAScript standard is still under development and may still change.

However Mascara supports a number of major ECMAScript 4 features, which makes it a powerful tool for developing serious JavaScript.

New slogan: The JavaScript of tomorrow, today.

A Project like Mascara is pretty useless without through documentation. Therefore I've published the beginnings of what is going to be through documentation of Mascara ECMAScript 4.

Among other things, there are pages about some of the new features in the latest releases, which I haven't gotten around to describe here on the blog:

• Triple quoting
  
• Readable regular expressions
• Array type literals
• Function types
• Array comprehensions
  

Version 0.5.5 has been realeased. We are getting very close to an official beta release. For convenience I provide both a zip and a tar.gz file for download.

[x*2 for each (x in [1,2,3])]

[a, b] = [1,2];

Version 0.4 is released now. Download.

Version 0.3.6 is now released. Numerous improvements:

static initializer blocks and static methods are now supported correctly. They work basically like in Java.

Array type literals are supported. They have an interesting syntax:

var a : [...int] = [1,2,3]; // a variable size array of integers
var b : [int, int, int] = [1,2,3]; //a fixed size array of three integers.

So the three dots mean "any number of". Fixed sized arrays can be heterogenous:

var c : [int, String, boolean] = [7, "hello", false];

And believe it or not, an array can even be a combination of heterogeneous types and variable size:

var d : [boolean, String, ...int] = [true, "hello", 1, 2, 3];

The first two items are boolean and String, end every item after is int.

Destructuring variable definitions is also supported now. This allows you to write:

var [a, b] = [1,2];

This is especially useful when returning arrays from a function, e.g.:

function f() { return [1, 2]; }
var [a,b] = f();