[Libguestfs] [PATCH 4/4] mltools: JSON: unify JSON_parser type with JSON.json_t.

[Richard W.M. Jones]

On Wed, Aug 22, 2018 at 03:18:31PM +0100, Richard W.M. Jones wrote:
> On Wed, Aug 22, 2018 at 01:20:55PM +0200, Pino Toscano wrote:
> > On Monday, 20 August 2018 18:02:06 CEST Richard W.M. Jones wrote:
> > > -  } else
> > > -    rv = Val_none;
> > > +  }
> > > +  else {
> > > +    /* Previously we had a special JSON_parser_null value we could
> > > +     * use here, making the returned type (sort of) an option.
> > > +     * This is a best effort which is better than crashing /
> > > +     * throwing an error.
> > > +     */
> > > +    rv = caml_alloc (1, JSON_STRING_TAG);
> > > +    v = caml_copy_string ("");
> > > +    Store_field (rv, 0, v);
> > > +  }
> > 
> > NACK, this is not correct.  null is a proper type of value in JSON, and
> > thus JSON.json_t must represent it as well.
> > 
> > This is even used in other parts, for example the check of backing
> > files of disks (see guestfs_impl_disk_has_backing_file).
> 
> Can you explain more about what a "null" JSON document looks like?

Oh I see, it's actually a special value.

I think I can add this.  I've pushed patches 1-3.

Rich.

-- 
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