Faster Array#/MutableArray# copies

[Roman Leshchinskiy]

Simon Marlow wrote:
>
> For small arrays like this maybe we should have a new array type that
> leaves out all the card-marking stuff too (or just use tuples, as Roman
> suggested).

Would it, in theory, be possible to have an "unpacked" array type? That
is, could we have constructors for which the length of the closure is
determined dynamically at runtime?

Roman