scope escaping

[Dicebot]

On Thursday, 6 February 2014 at 15:47:44 UTC, Adam D. Ruppe wrote:
> ...

Had only quick look at it but here are some things to remember 
that I have realised when drafting my own scope proposal:

1) passing scope arguments:

/* what to put here as qualifier? */ int[] foo(scope int[] input)
{
     return input; // this should work
     int[5] internal; // implictly scope
     return internal[]; // but this shouldn't
}

I think it makes sense to prohibit `scope` as explicitly named 
return attribute but make it inferrable via `inout`.

2) Transitivity & aggregation:

struct A
{
     scope int[] slice1;
     int[] slice2;
     int value;
}

void foo(int[] input) { }
void boo(ref int input) { }

void main()
{
     int[5] stack;
     A a; // is it different from "scope A a;"?
     a.slice = stack[]; // guess should be ok
     a.slice2 = new int[]; // should this?
     foo(a.slice1); // obviously fail
     foo(a.slice2); // but does this?
     boo(a.value); // I'd expect this to fail
}

Main problem with strict scope definition is that most seem to 
inuitively get what it is expected to do but defining exact set 
of rules is rather tricky.