Why is D unpopular?

[Walter Bright]

On 5/15/2022 11:51 PM, Siarhei Siamashka wrote:
> On Sunday, 15 May 2022 at 17:21:18 UTC, Walter Bright wrote:
>> In my experience, it is not an option to rewrite working C code into D.
>>
>> Note that I have successfully converted small and medium C code projects to D.
> 
> Don't these two sentences contradict each other? Unless I'm misinterpreting the 
> meaning of words "converted" and "successfully".

It means I have credibility when it comes to this topic.


>> 2. converting a program all at once does not work. It must be done 
>> incrementally, one function at a time
> Can you elaborate on this?

Doing it one function at a time means if your new build doesn't work, you only 
have one function to look at to find the error. This means orders of magnitude 
less time spent debugging.


> But once the job is done, long term maintenance is relatively 
> painless.

No, it isn't. I speak from experience. C's limitations makes for code that is 
brittle (very hard to refactor).


> D is good for rapid development of new code, but isn't great for long term 
> maintenance because of the language evolution and compatibility breakages. My 
> understanding is that many D projects and libraries died off because they could 
> not afford to keep up and can't be even compiled anymore.

I've brought forward code myself. The D1 => D2 transition was hard, but since 
then, it isn't that hard. But people don't want to bother with this.


> Well, everyone is doing this and bindings for popular C libraries are available 
> for most programming languages.

This vastly underestimates the scope of the problem.


> Do I understand it right that ImportC is intended for implementing major new 
> features in the existing old C projects using D language?

?

> One of the old C projects is the Linux kernel. I know that some people are 
> working on making it possible to develop some parts of the Linux kernel using 
> Rust language. Would ImportC make it possible to use D for developing some parts 
> of the Linux kernel and how is it different from what Rust people are doing?

I am unfamiliar with kernel development and its needs. It apparently is also 
written in a dialect of C with special compiler switches.