Proposal for design of 'scope' (Was: Re: Opportunities for D)

[H. S. Teoh via Digitalmars-d]

On Mon, Jul 14, 2014 at 10:41:10AM +0200, Jacob Carlborg via Digitalmars-d wrote:
> On 13/07/14 16:37, H. S. Teoh via Digitalmars-d wrote:
> 
> >We could, but how would that help static analysis within the
> >function's body, since the caller's scope is unknown?
> 
> Won't the caller's scope always outlive the callee's?
[...]

Yes, but since the extent of this scope is unknown from inside the
function body, it doesn't easily lend itself nicely to check things like
this:

	int* ptr;
	void func(scope int* arg) {
		ptr = arg; // should this be allowed?
	}

If we only know that 'arg' has a longer lifetime than func, but we don't
know how long it is, then we don't know if it has the same lifetime as
'ptr', or less. So it doesn't really let us do useful checks.


T

-- 
"I suspect the best way to deal with procrastination is to put off the procrastination itself until later. I've been meaning to try this, but haven't gotten around to it yet. " -- swr