Re: [Qemu-devel] [PATCH v4 2/3] qapi: Add a primitive to include other files from a QAPI schema file

[Benoît Canet]

The Thursday 13 Mar 2014 à 19:05:12 (+0100), Lluís Vilanova wrote :
> Eric Blake writes:
> 
> > On 03/13/2014 09:33 AM, Benoît Canet wrote:
> >>> We certainly can't do without comments.
> >>> 
> >>> JSON is designed for easy data exchange, but we use it as programming
> >>> language syntax.  Its restrictions make sense for easy data exchange,
> >>> but hurt our use.  We're not the first ones experiencing that pain:
> >>> http://json5.org/
> >>> 
> >>> No idea how much momentum this JSON5 thingy has...
> 
> > If we 's,#,//,', our comments magically fall in line with JSON5 syntax;
> > everything else in our files is already compliant with JSON5.
> 
> >>> 
> >>> Switch to JSON5 and call it qapi-schema.json5?
> 
> > This actually seems like a rather nice idea - but due to our choice of
> > comments, it means rewriting the bulk of the file and tweaking our parser.
> 
> >>> 
> >> 
> >> Hmm don't we want something that python and other language know how to 
> >> parse out
> >> of the box ? Or will we write yet another delicate work of art to parse it 
> >> ?
> 
> > Our existing parser would only need to learn a new comment syntax to
> > parse the subset of JSON5 that we currently actually use.  Parsing FULL
> > JSON5 would mean also learning about trailing commas, unquoted names in
> > name:value pairs, multiline strings, and alternative numeric
> > representations.  But a point made on the JSON5 page is that ES5
> > JavaScript already parses JSON5, just as it already parses original JSON.
> 
> Another option is to bump QEMU requirements to python 2.6 or later. Then we 
> can
> use the json parser that comes with python. A simple pre-processing could
> eliminate the comments before passing them to the json package for loading 
> into
> python structures. The commands/enums/etc should also be elements of a list 
> for
> it to work (that must be either changed on the qapi files, or hackishly
> "injected" before parsing).
> 
> 
> Lluis

I have an use case for this series.

Lluis: Do you plan to respin this series ? Or should I do it ?

Best regards

Benoît

> 
> -- 
>  "And it's much the same thing with knowledge, for whenever you learn
>  something new, the whole world becomes that much richer."
>  -- The Princess of Pure Reason, as told by Norton Juster in The Phantom
>  Tollbooth
>