DMD as cross-compiler

[Jacob Carlborg]

On Friday, 13 November 2020 at 03:33:05 UTC, Walter Bright wrote:
> On 11/12/2020 11:15 AM, Jacob Carlborg wrote:
>> Implementing druntime and Phobos without the C standard 
>> library will give a big opportunity to do things better.
>
> How so? (Not that you're wrong, I'm just genuinely curious.)

It might not necessary mean a better or different API for Phobos. 
But the lower level APIs could be better.

Classic examples are:

* Use arrays instead of pointers (or pointer length pair). 
`memcpy` would be:

void[] memcpy(void[] source, void[] destination); // I think it's 
more natural to pass the source first

* Better error handling. I think returning error codes or using 
`errno` is pretty bad error handling strategy. Even though 
exceptions might not be the right choice (unless something like 
this is used [1]), something like returning: `Result!(Value, 
Error)` might be better.

* No global symbols, i.e. not having to worry about conflicting 
names across multiple files

In short, all the reasons for which you created D in the first 
place ;)

Unfortunately there will still be some limitations due to how the 
kernel APIs use pointers and error codes/errno.

[1] 
http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0709r0.pdf

--
/Jacob Carlborg