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

[Lluís Vilanova]

Benoît Canet writes:

> 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 ?

I was waiting for some other series to get merged, since they conflict. But I
still did not change the "include" syntax.

I will probably not be able to get to this until May 1st.


Lluis


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