IDL binding generator

[puffnfresh]

Should be possible to take IDL:

http://en.wikipedia.org/wiki/Interface_description_language

And convert it to Roy type aliases:

type Document = {
  getElementById: String -> Element
} with Node

(etc)

Then with externs:

https://github.com/pufuwozu/roy/issues/17

We could:

external document = Document

[paulmillr]

So, it's adding static typing to existing things?

:+1:

[piranha]

Do you want to use some existing IDL? Or just Roy types? I don't really care though, anything would be nice.

[puffnfresh]

IDL definitions come with the DOM specifications (e.g. DOM level 2). They describe the type signatures used in those standards.

So for us: input is IDL, output is Roy type aliases. Using that we'd have statically typed bindings to the DOM.

[piranha]

Ah, great then, would really cool to have type-checked DOM manipulation! :)

[DamonOehlman]

I'd be happy to have a look at this one, if you had some pointers on where to start. I found an IDL grammar for antlr but haven't really got a good idea on how to convert this to something usable in JS land...

Compilers and parsers definitely aren't my strength, but I think this has some value and is reasonably self contained so would love to help out :)

[puffnfresh]

@DamonOehlman a better way to do this has come up since I filed it. Roy now outputs a .roym file which describes the exports of a module. The problem is that I haven't documented the format.

It looks something like:

obj: {x: Number, y: Number, t: String}

Where obj is an identifier the right hand side is a type. I'm guessing the IDL grammer will output something like this:

type Element = {
}
document: {
  getElementById: Function(String, Element)
}

Not sure if that will work since I haven't tested anything that complicated.

[puffnfresh]

Was told I should look into domconv, especially the WebKit fork (whose IDL contains some useful extensions):

https://github.com/ghcjs/domconv-webkit