Re: ancient convert rules

[Jean Abou Samra]

Hi Jonas,

Le 30/08/2020 à 15:38, Jonas Hahnfeld a écrit :
> For https://gitlab.com/lilypond/lilypond/-/issues/6024, I've been
> looking at python/convertrules.py and wonder if we really need all
> ancient rules starting from version 0.1.9. Right now, a majority of
> these won't even apply because Python 3 is much pickier about bad
> escape codes in the regular expressions. Example:
>      re.sub('\\musicalpitch', '\\pitch', s)
> is wrong because \\ only escapes for the string and neither \m nor \p
> are correct escapes in a regular expression. For this case, it's easy
> to fix with raw strings and I think I was able to resolve most errors
> so that all rules are able to run, but I've no way to guarantee that my
> edits are correct.

Ah, we were doing overlapping work, thanks for letting us know! I'll let
you go ahead.

> On 30/08/2020 14:38, Jonas Hahnfeld wrote:
> > To make the story short: Can we maybe instead drop any rules older than
> > 2.12.0? Its last minor release 2.12.3 is more than 10 years ago.
>
> I don't know.
>
> While it is more than 10 years ago, I seem to recall a lot of stuff on 
> Mutopia where there are LP files to use are from much older than 2010.

A quick searchin Mutopia's repository reveals that the oldest \version 
statement
there is 2.4.0. That release dates back to 2004. I think it would be 
fine to drop
rules prior to that version, or maybe 2.0.

> I think at the very least we should perhaps 'flag' anything (either as 
> a warning or as an error) for users that might have needed to convert 
> something that we have removed because of backward compatibility if 
> they tried to use such a convert-ly file. Rather than look like it has 
> worked until they try to compile it with the later code and then get 
> an error and open a bug report (if you see what I mean).

It should be made to error out when conversion from a version older that 
2.4.0 or
whatever is attempted, I guess. Does that address your concern?

Best,
Jean