Re: Lua and backwards compatibility - was Re: [ANN] Lua 5.3.4 (rc2) now available,

[Marc Balmer <marc@...>]

Am 12.01.17 um 01:02 schrieb Dibyendu Majumdar:
> On 11 January 2017 at 21:06, Hisham <h@hisham.hm> wrote:
>> On 11 January 2017 at 17:08, Roberto Ierusalimschy
>> <roberto@inf.puc-rio.br> wrote:
>>>> Please, do not make such a severely breaking change in a 5.3.x release.
>>>
>>> We did not realize that. It will be corrected.
>>
>> Thank you! :)
>>
> 
> Hi,
> 
> I was wondering if it is possible to consider making strong backwards
> compatibility guarantees for Lua from 5.3 upwards. I think this will
> mean some constraints to Lua's development obviously, but it would
> strengthen Lua 's ecosystem.

If the wheel was not constantly being reinvented, we would still be
driving on bumpy rocks...

If you want to be compatible with ancient Lua, why don't you just use
ancient Lua?

> The strongest argument I could make is that Lua is built on C, and
> imagine how difficult it would have been if C had kept changing in
> incompatible ways every few years, and all new C compilers stopped
> supporting older versions of C.

C has changed a lot in incompatible ways.  Todays C is not the C I used
decades ago.

> The other argument for a compatibility promise is to try and bring
> everyone up to 5.3 at least. If the language again changes in an
> incompatible way that then you will end up with users in 5.1, 5.2, 5.3
> and future versions. I think this fragmentation is not beneficial to
> Lua.

How is that Lua's fault it lazy people are not going to update their stuff?

> I was thinking initially of requesting that "Lua be frozen" as a
> language ... but that is maybe too radical a thought.

Yes.

> I think we can see from experience that languages that have done this
> - i.e. maintained strong backwards compatibility - such as C, C++,
> Java, C#, Go, have all benefited from it. We see also the struggle
> being faced by Python moving everyone to 3.x, and similarly the
> fragmented ecosystem of Lua.

Oh and then there is more fragmentation going on, I remember one guy
wrote a thing called Ravi we added, well, to the fragmentation...