Re: [xdi] Metagraph symbols ==> Metagraph $words

[Michael Schwartz <mike@gluu.org>]

I agree! I think this is important for security. Lack of clarity can lead 
to mistakes.

Also, I think it needs to be pointed out that we are talking about 
switching $, *, and ! where these symbos are are used as shorthand for 
predicates. Correct?

thx,

Mike


--------------------------------------------------------------------------------------

Michael Schwartz
Gluu
Founder, CEO
https://www.gluu.org



On Tue, 21 Jun 2011, Drummond Reed wrote:

> I have done the first part of the action item I had from the last telecon to
> analyze moving back from metagraph symbols to semantically-meaningful
> English $words.
>
> As I expected, for three of the four, the translation is very easy
>
> Metagraph symbol  ==> $word
> $  ==>  $is  (inverse is the same)
> *  ==>  $has  (inverse is $is$has)
> !  ==>  $a  (inverse is $is$a)
>
> These all would be used just as we have used them for the past several
> years.
>
> The only metagraph symbol that does not have a good English equivalent is ()
> -- the metagraph symbol for subcontext. After thinking about this over the
> weekend, I realized there is a reason there is no good English word for
> expressing a pure subcontext relationship the way we use () in XDI
> statements, e.g.:
>
> +snow/()/+ski
> +water/()/+ski
> @Rossignol/()/+ski
>
> The reason is that when you translate these XDI statements into English, the
> semantics of the () context symbol are expressed by...WHITESPACE!
>
> snow ski
> water ski
> Rossignol ski
>
> It is literally the left-to-right order of the English words, delimited by a
> space, that expresses the supercontext/subcontext relationship.
>
> No wonder we could never find the right word for it! And also a good case
> for why (), the metagraph symbol for subcontext, should remain a symbol.
> Expressing the inverse, supercontext, will be $is(), following the same rule
> as all of the other metagraph $words above.
>
> So, the proposal is to move back to the $words $is, $has, and $a instead of
> the metagraph symbols for $, *, and ! when they are used as predicates in
> XDI statements. If everyone is in agreement about this, I will draft a new
> wiki page called MetagraphWords to replace
>
>  http://wiki.oasis-open.org/xdi/MetagraphSymbols
>
> Please post if you don't agree.
>
> =Drummond
>