Slice semantics was: Re: Herb Sutter briefly discusses D during interview

[Ali Çehreli]

On 06/08/2011 10:38 AM, Ali Çehreli wrote:

 > If we need to think about what
 > the compiler does or how a specific language feature is implemented,
 > that language is a failed abstraction. D is not. There shouldn't be any
 > need to get into implementation details to describe a language feature.
 >
 > This used to happen with D slices: some people would point to pictures
 > of slices where .ptr pointed to the beginning of some elements in
 > memory. That way of describing slices would not work on beginners who
 > have no idea on what a pointer is, especially in a language where
 > pointers can be avoided for a long time.

Allow me to contradict myself: I've tried to pinpoint the semantics of 
D's slices in the past, but have failed. I remember focusing on 
"discretionary sharing semantics."

The apparent non-deterministic behavior related to non-stomping makes it 
hard ("impossible" for me) to describe the semantics of slices. Steve 
had to get into implementation details in his "D Slices" article to 
describe that non-determinism. I think that strengthens my view that 
slices cannot be fully described without getting into implementation 
details.

Ali