Feedback Thread: DIP 1034--Add a Bottom Type (reboot)--Community Review Round 1

[Dennis]

On Monday, 11 May 2020 at 08:48:47 UTC, Piotr Mitana wrote:
> noreturn look more like a keyword also due to its similarity to 
> return keyword.

I don't see a problem with that. Many syntax highlighters 
highlight `string` like a keyword. The fact that it's technically 
an alias is unimportant.

> noreturn suggests clearly that the function will not return, 
> but it is natural only for this use of the bottom type, and as 
> the DIP states, there are more uses.

Just about the only time you actually need to spell out the 
bottom type is when marking a function to not return, so the name 
is tailored to that use case.

```
// Why write a non-template function like this?
noreturn[] getEmptyArray() {return [];}
void takesNullPointer(noreturn* ptr) {}

// This is what you actually write
noreturn panic(string msg) {assert(0, msg);}
```

> Although returning nothing is a little bit less clear that 
> noreturn, everyone knows void, so it has to be something 
> different.

So `nothing` is synonymous with `void`, but people are familiar 
with `void` so they'll figure `nothing` must refer to something 
different than `void`, such as `noreturn`. I have my doubts about 
that. I think it will be confusing, while `noreturn` is clear as 
day.

> And nothing[] looks much more in place then noreturn[].

If I really needed to spell it out in non-generic code, I would 
just write `typeof([])`, and for `noreturn*` use `typeof(null)` 
(which is the name the compiler uses currently).