Re: cleanups with long-term benefits (was Re: [PATCH] schemas: Add vim modeline)

[Paolo Bonzini]

On 03/08/20 18:03, Markus Armbruster wrote:
>> In general it seems like a good idea to use a standard file format and
>> not "a standard file format except for two characters". :)  We also
>> wouldn't be having discussions on editors.
> 
> No argument.  But towards which standard file format should the schema
> evolve?
> 
> * Standard JSON: no comments, no go
> 
> * JSON with # comments: need to change strings from ' to "
> 
> * JavaScript: need to change comments from # to //
> 
> * Python: may want to switch bool literals from true, false to True,
>   False

Second or third, I'd say.  I dislike using .py because a stream of
Python objects doesn't really have a meaning in Python: that's the
difference between .js and .json.

Third requires someone to do the work in the parser.  Unlikely.

>> That said, after a bit more research I'm skeptical about the possibility
>> of using an off-the-shelf parser because most of them either don't
>> support comments, or are based on YAJL which simply discards comments.
>>
>> Since '//' comments are harder to parse than "#" comments, this would
>> actually _add_ code instead of removing it.  Also since our doc comment
>> syntax uses "##" as a delimiter, we'd have to bikeshed what the doc
>> comments would look like ("//!", "///", etc.).
> 
> Doc comments don't have to be comments in the schema language.  They
> could be doc strings.  Requires decent support for long strings, which
> JSON does not provide.

Exactly.  This was the appeal of YAML (or StrictYAML so that Norwegians
don't turn into Falsians) as far as I understood.  But if we were to go
YAML, I'd rather have make doc strings part of the YAML document too.
That is what Nir suggested, it makes sense but someone has to write the
conversion code.

> If all we want is decent editor support out of the box, then rename to
> .py, and drop the modelines.  No merge conflicts, no git-blame
> pollution.

Another possibility is to rename to .qapi and keep Python modelines as a
hack that does work.

Paolo