Imba – A new programming language for the web

It's confusing they made a whole nice language that doesn't speak about react VDOM diffing which .. was the whole point right ?

This isn't a competitor to react; its a competitor to ES6/typescript/coffeescript.

React is a template library, not a language.

JSX is a way to write templates, but that's not react, and its not what react does. It's just a shortcut to writing XML.

You could say this is a competitor to JSX, perhaps; but anything more is hyperbole.

People aren't using react and angular because they have a nice syntax, that's just nice, they use them because you can build applications with them.

How do you build ui components using imba? Use react? :P

I suppose the idea is that 'compile' implies a low-level target whereas 'transpile' suggests translating to another high-level language. I can see some sense in making this distinction.

There's two parts of the "very efficient rendering":

1. It store the previous rendered tag and does a diff. (Just like React).

2. Every tag is compiled to JavaScript that's easy for the optimiser.

    tag event 
           "Hello world!"

Compiles to:

    // Setting up the tag-object. Then:
     tag.prototype.render = function() {
       return this
         .setChildren(Imba.static([
           (this.$a = this.$a || t$('h1').setBar("123")).setBaz(bar)
         ], 1))
         .setText("Hello world!")
         .synced()
    }

While React passes an object of props around, Imba will instead call setters. These setters are very easily inlined by modern browsers. Also note that it caches directly on the tag object itself which gives another additional boost. Since it caches the objects themselves it can also compare everything with `===` and/or `indexOf`.

The `Imba.static`-call marks an array as static which is a guarantee that the structure of the array won't change. In this case Imba will not do the full diff-algorithm, but instead compare each item element-by-element.

And yes, once you've achieved the minimal amount of DOM changes needed (like React), the next step for performance is all of these little tweaks. Does it matter? It all depends. Imba is capable of rendering bigger applications than React when you use the "render everything over again in the animation loop".

TLDR: The tags are more integrated into the language. The language is also designed around features that's easy for the optimiser.

Looks like Twilight (which started life with Textmate, but has taken off all over since), or a variation thereupon.