Deprecation

[Tomas Mraz]

On Fri, 2020-02-14 at 12:30 +1000, Dr Paul Dale wrote:
> There is some pushback against the deprecations going on in various
> PRs.
> 
> The plan has always been to deprecate engines in 3.0 and removing
> support for them 5+ years later.  Originally, the path was to have
> included an engine provider that could load engines and make them
> appear to be a provider.  After a fair amount of investigation, this
> was deemed to be too difficult in the 3.0 time frame.
> 
> Do we still want to deprecate engines in 3.0?
> Should we defer until 4.0 instead?
> 
> 
> The main benefits seem to boil down to continuing to support existing
> engines vs removing the legacy code paths and switching to the
> provider model.


I do not understand the pushback too much - Perhaps it could be
resolved by proper explanation that deprecation does not mean a
removal?

Also even if some stuff deprecated in 3.0 is removed in 4.0, it does
not necessarily mean that engines must be removed in the same release.
They can continue to be supported (just deprecated) until 5.0 for
example.

I think that doing the deprecation as early as possible is better - it
properly gives the signal that the engine interface is legacy and it
will disappear at some point. It provides more time for 3rd party
engines to transform into providers.

-- 
Tomáš Mráz
No matter how far down the wrong road you've gone, turn back.
                                              Turkish proverb
[You'll know whether the road is wrong if you carefully listen to your
conscience.]