[swift-evolution] Swift-based Metal Shading Language

[Goffredo Marocchi]

Sent from my iPhone

On 10 Jul 2016, at 08:50, Georgios Moschovitis <george.moschovitis at icloud.com> wrote:

>> working on C++ compatibility/interaction is  still quite key because of the mountains of legacy and new code still written everyday in it.
> 
> Totally agree, but C++ interoperability is orthogonal to my original request. Would love to have both!
> 
>> Also, I think that the right language for the right domain and being able to glue them together is quite key in the modern computing world and using a single language in every computing domain is a chimera that can bring more pain than good.
> 
> I disagree. IMO, the ‘babel’ of programming languages is one of the most annoying problems in our industry. Besides, I don’t see how C++ is any more suitable than Swift for GPU/heterogenous stuff (without peculiar extensions like CUDA). Swift is starting from a clean-slate, and could definitely become a ‘right’ language for this domain.

DSL's sometimes emerge to esse programming challenges, but often arise out of need to dominate the complexity of a domain by catering exclusively to it instead of a jack of all trades - master of none approach. In some cases, the ability to easily approach problems in a deterministic low level way, as well as the wealth of existing code dealing with those problems, is how C and C++ are still very very relevant. The rest is increasingly dominated by JavaScript and Node where performance at a very low power is not critical.

C++ gives you rope to hang yourself with, but in capable hands it gives you all the knobs and levers you need to extract high performance with a very high degree of determinism. 
Garbage collection, automatic reference counting, pass by copy value types with or without copy on write semantics, etc... there are several areas where other languages keep you abstracted from the hardware in a way that does not make performance predictable.
Memory fragmentation, control of allocations of stack and heap memory (preferably away from hot game loops), no extra performance hit when passing memory reference around or iterate on collections (yes people can destroy performance in not very obvious ways too).