keyval: Document issues with 'any' and alternate types

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1490014548-15083-5-git-send-email-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
This commit is contained in:
Markus Armbruster 2017-03-20 13:55:47 +01:00
parent 599c156bac
commit 0ee9ae7c8c

View File

@ -61,6 +61,16 @@
* "key absent" already means "optional object/array absent", which
* isn't the same as "empty object/array present".
*
* Design flaw: scalar values can only be strings; there is no way to
* denote numbers, true, false or null. The special QObject input
* visitor returned by qobject_input_visitor_new_keyval() mostly hides
* this by automatically converting strings to the type the visitor
* expects. Breaks down for alternate types and type 'any', where the
* visitor's expectation isn't clear. Code visiting such types needs
* to do the conversion itself, but only when using this keyval
* visitor. Awkward. Alternate types without a string member don't
* work at all.
*
* Additional syntax for use with an implied key:
*
* key-vals-ik = val-no-key [ ',' key-vals ]