Re: [Qemu-block] [Qemu-devel] Non-flat command line option argument syntax

[Paolo Bonzini]

On 04/02/2017 01:45, Markus Armbruster wrote:
>>>      -drive driver=qcow2,
>>>             file.driver=gluster,
>>>                 .volume=testvol,
>>>                 .path=/path/a.qcow2,
>>>                 .debug=9,
>>>             file.server.0.type=tcp,
>>>                          .host=1.2.3.4,
>>>                          .port=24007,
>>>             file.server.1.type=unix,
>>>                          .socket=/var/run/glusterd.socket
>>>
>>> Mind, I'm not at all sure this is a *good* idea.  I suspect it's more
>>> magic than it's worth.
>> As someone who likes dot syntax very much, I don't like it. If you
>> structure it like this, it's OK, but then you can just write the full
>> prefix (which gets the point across just as well because I can quickly
>> tell from a glance that it's the same prefix).
>>
>> OTOH, when joined into a single line it doesn't change much in terms of
>> legibility, in my opinion.
> 
> Thanks!

Actually I think it does improve legibility.

It doesn't improve writability though, as anecdotally proved by Markus's
own mistake.

I am a fan of the dot syntax too.  It seems to be the most incremental
solution, and it's still as expressive as JSON.

_However_ we could also extend -readconfig to support JSON, i.e. instead of

        [drive "abc"]
                file = "foo"

it could support

        { 'drive': { 'file: 'foo' }, 'id': 'abc' }

In other words [ would introduce key-value QemuOpts with dot syntax,
while { would introduce JSON.

Paolo