Reimplementing the bulk of std.meta iteratively

[Steven Schveighoffer]

On 9/29/20 2:43 PM, bachmeier wrote:
> On Tuesday, 29 September 2020 at 14:07:14 UTC, Andrei Alexandrescu wrote:
>> There is no doubt to Walter or myself that the way built-in AAs were 
>> done in D is a resounding failure.
> 
> If so, it's a pretty good resounding failure, because I like them and 
> they would most likely not be available to me now if they hadn't been 
> built into the language. Long ago when I used Common Lisp, there was the 
> incredible FSet library that provided functional collections kind of 
> like Clojure. Unfortunately few people knew about them or used them, and 
> it doesn't look like anything has been done with them in a long time: 
> https://common-lisp.net/project/fset/ Sometimes a library solution 
> works, but it's in general a risky proposition to rely on libraries for 
> such a fundamental feature.
> 
> If AAs had been introduced as a library in 2012, the repo would probably 
> have a couple hundred open issues and the last development would have 
> been in 2017.
> 
>> The way they should have been done was a templated library type 
>> AssociativeArray!(K, V) with the V[K] type syntax sugar on top. That 
>> would have allowed the implementation to improve along with the rest 
>> of the language and its library.
> 
> Does anything prevent the introduction of a new library solution? If 
> it's good enough, it can eventually be added to the language.
> 
> I'm not going to pretend to be a language designer. My experience as a 
> language user is that a big set of core functionality works better than 
> a small set plus libraries. It's possible I don't understand your proposal.

I think there's some disconnect here -- AAs as a language feature are a 
resounding success. They way they are implemented in the language is 
not. I wouldn't call it a failure, but it definitely is not as useful as 
a fully supported library type could be.

-Steve