Nouveau - Oct 2025 - [PATCH 5/7] gpu: nova-core: add extra conversion functions and traits

On 10/26/25 9:44 AM, Miguel Ojeda wrote:
> On Sun, Oct 26, 2025 at 3:40?PM Alexandre Courbot <acourbot at
nvidia.com> wrote:
...
> Regarding the `.into_as()` name, it makes sense, but it can be a bit
> surprising when reading out of context... The standalone functions are
> super clear, in comparison. But I am not sure what could be better.
> `into_in_this_arch()` or similar could emphasize that this will only
> work in certain architectures, i.e. it is "an `into()` for this
arch"
> rather than the general one.
> That would go well with the idea that you didn't implement it for
> other obvious types, which I guess was to avoid developers using this
> instead of `into()` by mistake, right?
> 
Exactly: the into-as, from-as naming suffers from *appearing* to be
familiar and readable, but actually, the naming gives no hint as to 
what it is really doing--nor how it is subtly different from the
basic from/as/into standard conversions.

Instead, we need to add something (almost anything) to the name, to
make it clearly different from the from/as/into.

into_for_arch() goes in that direction, for example.

thanks,
-- 
John Hubbard

On 10/27/2025 2:46 PM, John Hubbard wrote:
> On 10/26/25 9:44 AM, Miguel Ojeda wrote:
>> On Sun, Oct 26, 2025 at 3:40?PM Alexandre Courbot <acourbot at
nvidia.com> wrote:
> ...
> 
>> Regarding the `.into_as()` name, it makes sense, but it can be a bit
>> surprising when reading out of context... The standalone functions are
>> super clear, in comparison. But I am not sure what could be better.
>> `into_in_this_arch()` or similar could emphasize that this will only
>> work in certain architectures, i.e. it is "an `into()` for this
arch"
>> rather than the general one.
>> That would go well with the idea that you didn't implement it for
>> other obvious types, which I guess was to avoid developers using this
>> instead of `into()` by mistake, right?
>>
> 
> Exactly: the into-as, from-as naming suffers from *appearing* to be
> familiar and readable, but actually, the naming gives no hint as to 
> what it is really doing--nor how it is subtly different from the
> basic from/as/into standard conversions.
> 
> Instead, we need to add something (almost anything) to the name, to
> make it clearly different from the from/as/into.
> 
> into_for_arch() goes in that direction, for example.
100% agree with John. Thanks,

 - Joel

On Tue Oct 28, 2025 at 3:46 AM JST, John Hubbard wrote:
> On 10/26/25 9:44 AM, Miguel Ojeda wrote:
>> On Sun, Oct 26, 2025 at 3:40?PM Alexandre Courbot <acourbot at
nvidia.com> wrote:
> ...
>
>> Regarding the `.into_as()` name, it makes sense, but it can be a bit
>> surprising when reading out of context... The standalone functions are
>> super clear, in comparison. But I am not sure what could be better.
>> `into_in_this_arch()` or similar could emphasize that this will only
>> work in certain architectures, i.e. it is "an `into()` for this
arch"
>> rather than the general one.
>> That would go well with the idea that you didn't implement it for
>> other obvious types, which I guess was to avoid developers using this
>> instead of `into()` by mistake, right?
>> 
>
> Exactly: the into-as, from-as naming suffers from *appearing* to be
> familiar and readable, but actually, the naming gives no hint as to 
> what it is really doing--nor how it is subtly different from the
> basic from/as/into standard conversions.
>
> Instead, we need to add something (almost anything) to the name, to
> make it clearly different from the from/as/into.
>
> into_for_arch() goes in that direction, for example.
I'd like to get more input on that, for I am not sure how we can stay
succint in the naming, while carrying the relevant information.
`into_arch` does not sound much more explanatory than `into_as` - the
intent with the latter was to say "I would normally have done an `as`,
but instead here is a method that attests that this operations is indeed
lossless and safe".

The best naming scheme I could think of is to have the methods carry the
source or destination types: e.g. `from_usize` or `into_usize` (like the
standalone functions), but that would require defining as many traits,
and increase the number of imports - if we go that way, we might just as
well drop the traits completely and use the standalone functions.

`into_native` also comes to mind, but like `arch`, it can mean many
things depending on the context.

... I think I still believe that `into_as` is the clearest name, once
one has read the documentation for the trait - which one should be
expected to do anyway. :)