Generic and fundamental language design issue

[Paulo Pinto]

Am 04.11.2012 18:41, schrieb Andrei Alexandrescu:
> On 11/4/12 12:35 PM, Tommi wrote:
>> I have a fundamental language design talking point for you. It's not
>> specific to D. I claim that, most of the time, a programmer cannot, and
>> shouldn't have to, make the decision of whether to allocate on stack or
>> heap.
>
> I don't think that claim is valid. As a simple example, polymorphism
> requires indirection (due to variations in size of the dynamic type
> compared to the static type) and indirection is strongly correlated with
> dynamic allocation. Also, the value vs. reference semantics of type are
> strongly correlated with where objects should go. So on the contrary,
> quite often heap vs. stack allocation is forced by the nature of what's
> allocated.
>
> Andrei
>

Java and Go work around this issue using escape analysis, in opposite 
directions though.

In Java most JITs can allocate objects in the stack if they see the 
object does not escape the local scope.

Go goes the other way, by allocating in the heap local objects that are 
usually allocated on the stack but are returned the caller.

--
Paulo