Re: [Jmap] Adding the Message::isForwarded property

[Neil Jenkins <[e-mail]>]

The initial JMAP design was only interested in the system flags, so
having the separate properties made sense. But given we want to add full
support for custom IMAP flags (and reuse the IANA registry), I think
having the system ones in a different format is going to end up causing
pain down the line. We could make properties for the keywords currently
in the IANA registry, but this would clearly cause headaches as more are
standardised down the line. So I agree we should change to just a single
"keywords" property, and reuse the keyword names from IMAP.
This means we would remove the "isUnread", "isFlagged", "isAnswered" and
"isDraft" properties from the Message object and introduce a single
"keywords" property (with respectively "\Seen" (flipped meaning),
"\Flagged", "\Answered" and "\Draft" keywords, as per IMAP).
The main downside is I think  is this is slightly less accessible for
newcomers who haven't been exposed to IMAP, but this is probably
outweighed by the benefits already discussed.
Do we have consensus on this? The last few messages all seem to be in
favour of making this change. If so, I'm happy to update the spec and
call this issue closed.
In terms of representation, do we agree on an Object type, with the
keywords as the keys (and a boolean `true` as the value (as discussed in
a previous email in this thread)?
Neil.