Evolving the D Language

[IchorDev]

On Friday, 7 July 2023 at 13:19:51 UTC, Nick Treleaven wrote:
> Changing the syntax just for an obsolete feature would send the 
> wrong message.
> [...]
> cent and ucent are already an error as of 2.100. Were they even 
> implemented?

Clearly you're not looking at this the same way as me, [or 
Walter](https://github.com/dlang/dmd/pull/15393).
Fixing old code isn't the only upside to resurrecting old 
features.

First thing, I think all languages should support binary, octal, 
decimal and hexadecimal literals as a baseline. Octal is probably 
the least important of them, but can still be plenty useful in 
its own right. You technically don't need *any* numerical 
literals at all in D, you could make all of them with 
string-to-number templates. You could take such an approach to 
just about everything in D, actually! On the other hand, people 
working on low-level Linux code might be pretty appalled to find 
out that they can't simply use octal literals to represent file 
permissions in D.

Second, I think re-examining and sometimes resurrecting features 
that were removed from D, no matter how long ago, is important.
Think about it this way, the only reason D doesn't have octal 
literals right now is because when it did have octal literals the 
syntax was ambiguous. The solution at the time was removing them 
from the language, but had their syntax been modified at the time 
then they wouldn't have been ambiguous. Who says it's too late?

There are a few D features that were poorly implemented (or not 
implemented at all), and then simply removed instead of being 
fully reconsidered. You might say that for many, they were indeed 
reconsidered, and then added to Phobos instead. Now some of these 
features pre-date BetterC, of course, but I am a regular BetterC 
user. A feature being moved to Phobos translates to "you don't 
get to use this in most of your code anymore" for me. I'm not a 
user of complex or imaginary types, but I don't see why they 
needed to be removed from D, were they a huge burden to maintain 
compared to being in Phobos?

TL;DR I think we should be more lenient about leaving features in 
the language if they aren't in the way, and consider ways of 
modifying them rather than removing them from the language if 
they get in the way.