Dart bindings for D?

[Suliman via Digitalmars-d-learn]

> It is possible, but you need to design the language within the 
> constraints of javascript:
>
> 1. single threaded (or worker threads)
>
> 2. 53 bits integers, 26 bits for multiplies.
>
> 4. "weird" fixed size heaps (ArrayView)
>
> 5. if garbage collection then it has to be javascript style
>
> 6. no tricks: forget coroutines

I can't understand why this restructions?  Could you explain them?