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

On Tue, Jun 21, 2011 at 9:27 PM, Drummond Reed <drummond.reed@xdi.org> wrote:

Mike, yes, we are talking about switching the symbols $, *, and ! just where these symbols are used as "shorthand" for XDI predicates. The use of those symbols elsewhere in XDI is not affected. For example, the use of ! as the trailing delimiter for an XDI literal predicate (e.g., =drummond/+age!) still applies. And the use of ($) for variables still applies.

=Drummond

On Tue, Jun 21, 2011 at 12:07 PM, Michael Schwartz <mike@gluu.org> wrote:

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

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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

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