Full closures for D

[Bruce Adams]

Martin d Anjou Wrote:

> >>  It's not an optimal solution because the "does the function escape"
> >>  heuristic captures too many functions.
> >
> > You could let the programmer specify explicitly whether or not to make a 
> > function a closure or not, maybe with a key word or something.
> 
> A programming language called Vera uses the "shadow" keyword to acheive a 
> somewhat related effect.
> 
> From http://www.asic-world.com/vera/concurrency_control1.html:
> 
> program shadow_variable {
>    spawn_process() ;
>    delay(100) ;
>    spawn_process_with_shawdow();
>    delay(100) ;
> }
> 
> task print(integer i) {
>    printf("   n = %0d\n", i);
> }
> 
> task spawn_process () {
>    integer n;
>    printf("In spawn_process\n");
>    for(n=0; n<3 ; n++) {
>      fork
>        print(n) ;
>      join none
>    }
> }
> 
> task spawn_process_with_shawdow () {
>    shadow integer n;
>    printf("In spawn_process_with_shadow_variable\n");
>    for(n=0; n<3 ; n++) {
>      fork
>        print(n) ;
>      join none
>    }
> }
> 
> Executing this code gives:
>   In spawn_process
>      n = 3
>      n = 3
>      n = 3
>   In spawn_process_with_shadow_variable
>      n = 0
>      n = 1
>      n = 2
> 
> I am not a language expert, but this seemed related.
> 
> Martin

I see the analogy but this is actually about whether a variable should be shared between 2 threads / processes. I don't think there is a native D equivalent but "shared" has been proposed several times.
This would be more like "export".