A rationale for pure nothrow ---> @pure @nothrow (and nothing else changes)

[Don]

Michel Fortin wrote:
> On 2010-02-25 14:11:02 -0500, Don <nospam at nospam.com> said:
> 
>> Michel Fortin wrote:
>>> To me, an attribute should be seen like this:
>>>
>>> """
>>> If something is an attribute, then it's accessory to the language. 
>>> Something is accessory when you can remove it completely from a 
>>> program and expect the program to compile and behave the same. 
>>> Attributes are not changing anything beside adding some restrictions 
>>> to improve safety, optimization, etc.
>>> """
>>
>> Please. *I* invented that rule.
> 
> I did not claim I invented it, just that this is what I think should be 
> an attribute. It's very possible I was influenced by your previous posts 
> into thinking this, but I'm not always tracking perfectly where each of 
> my opinions come from. Sorry if I overexplained everything to you.

The point is that it's been previously discussed, and it doesn't work.

> I quite agree that having pure as @pure and nothrow as @nothrow would be 
> better than nothing.
> 
> If you want a rationale that works for everything beside pure and 
> nothrow, I think it'd work better to just say that new keywords added in 
> version 2 of D that behave as attributes(*) use the @attribute syntax. 

You could say that. It's pretty much the same as the list from 'C-family 
languages'. we don't care about backwards compatibility with keywords 
from D1.

> If pure and nothrow stay like this, just add a cutoff date to the above.

That isn't any better than an arbitrary list.

> (*): http://www.digitalmars.com/d/2.0/attribute.html
> 
> I know you're trying to avoid this kind of "historical incident" kind of 
> rule, but making a rule that depends instead on the history of C-derived 
> languages doesn't really improve things in my opinion.

No, I'm trying to avoid a "prehistorical accident" type of rule.

For these purposes, the history of D begins when TDPL is published. 
We're still in prehistory for a few more weeks.

Compatibility with C and C++ has always been critical for D; D contains 
many historical accidents from C. But D has not yet set any historical 
precedents.

If we simultaneously release a language with @attributes, together with 
attributes that don't use them, it looks silly.