On Friday, 9 June 2023 at 16:22:15 UTC, H. S. Teoh wrote:
> I wasn't around during the D1/D2 split, but AFAIK there were D1 projects that eventually had no way to transition to D2 because of fundamental language discrepancies that had no migration path.

Indeed.

So worth noting that the D1/D2 split happened almost simultaneously: D2 came out about six months after D1. What happened previously is there was just the D language that changed randomly as it wanted. People asked for some long term support.

D1 was arbitrarily branched off. It became the "stable" version and the existing all-development version got rebranded D2.

This actually was a decent success for a while! Some big users stayed on stable successfully. But the stable thing eventually got dropped with no migration plan, and then there was never another stable release to replace it.

Would want to avoid repeating those latter mistakes.

On Fri, Jun 09, 2023 at 04:41:28PM +0000, Adam D Ruppe via Digitalmars-d wrote:
> On Friday, 9 June 2023 at 16:22:15 UTC, H. S. Teoh wrote:
> > I wasn't around during the D1/D2 split, but AFAIK there were D1 projects that eventually had no way to transition to D2 because of fundamental language discrepancies that had no migration path.
> 
> Indeed.
> 
> So worth noting that the D1/D2 split happened almost simultaneously: D2 came out about six months after D1. What happened previously is there was just the D language that changed randomly as it wanted. People asked for some long term support.
> 
> D1 was arbitrarily branched off. It became the "stable" version and the existing all-development version got rebranded D2.
> 
> This actually was a decent success for a while! Some big users stayed on stable successfully. But the stable thing eventually got dropped with no migration plan, and then there was never another stable release to replace it.
> 
> Would want to avoid repeating those latter mistakes.

See, to me this proves that:

(1) LTS is viable for D;

(2) A migration path must be provided to move between LTS releases.

Point (1) is simple, at least in theory. (Well, simpl*er*, anyway.)

Point (2) is something we need to work on.  There should be a clear migration path for every breaking change introduced to the language, and this should be well-documented in a well-known place.  Probably it's too onerous to do this for every release (though ideally that should be the case), but at the very least there should be a solid migration plan from one LTS release to the next.

That way, users who want/need stability will have a way to migrate to newer releases, and won't be left behind with a 10yo obsolete compiler because there's no migration path. Users who don't mind breakages every now and then can just stay with the current releases.


T

-- 
Caffeine underflow. Brain dumped.

My general feeling is the LTS should be based upon what is required to bootstrap the compiler.

But yeah, this kinda needs rights to happen with branches & coordination. Not something that can be made to happen on the N.G. needs an industry meeting with someone wanting to do it I think.

On 09/06/2023 11:42 PM, Guillaume Piolat wrote:
> I don't believe a D LTS would solve things

It does have some strong benefit, wrt. bootstrapping of the compiler.

So it solves more long term things, rather than short or medium term issues I think.

On Friday, 9 June 2023 at 08:05:18 UTC, Walter Bright wrote:
> On 6/8/2023 7:56 AM, GrimMaple wrote:
>> The truth is, I've been nagging about LTS branches, and I've been nagging directly to Mike about it, and it went nowhere.
>
> It's not about not caring about it. It's just that I can't see how it would be effective. Making LTS versions balkanizes the language into multiple languages, which will play hell with 3rd party library maintenance.
>
> Clearly, the deprecation scheme is not serving our users well. We'll have to find a better way.

2 versions is hardly balkanizing

Given even 1 wave of depreciations I would have dropped dlanggui; if grim says he needs an lts to continue supporting that ancient project I think theres a simple question:

Would you rather make an lts or let dlanggui die entirely?

On 09/06/2023 8:05 PM, Walter Bright wrote:
> It's not about not caring about it. It's just that I can't see how it would be effective.

Not making the compiler versions required to bootstrap the compiler LTS dooms our very ability to have a working compiler.

Without having C++ dumps of the compiler, before we did the whole self hosting thing was kinda short sighted.

Having LTS versions which work towards bootstrapping would certainly be beneficial to us long term and would allow us to solve the problem for the wider community who need stabilization.