[cap-talk] Potting the web-calculus in a paragraph

[Ian G]

Tyler Close wrote:
> On 12/4/05, Ian G <iang at systemics.com> wrote:
> 
>>Marc Stiegler wrote:
>>
>>>"Secure bookmarks" is the term I am trying to popularize for the form of
>>>YURLs that are created and used by the Waterken web server today (I have
>>>found that the term "secure bookmark" leads many people to a quick
>>>intuition of the idea, while "web calculus, though it is a more accurate
>>>definition, is daunting and does not lead to the intuitions as quickly).
>>
>>Yes.  I've never had any clue what it referred
>>to, and I have done a lot of calculus in the dim
>>dark past...  I suppose it means something to
>>some of the people here, but I doubt anyone
>>outside the deep caps circle will appreciate it.
> 
> 
> Let's see if this helps:

Thanks for this!

> The web-calculus is an interface model describing how web sites can
> securely interact. Interfaces are composed from two structural
> elements: web pages and cap URLs. A cap URL is a URL that contains an
> unguessable secret and is only ever used over SSL. There are only two
> operations for manipulating this interface: GET and POST. A GET
> operation fetches the web page currently referred to by a cap URL. A
> POST operation consumes a list of arguments, each of which is either a
> web page or a cap URL, and returns a single output argument, which
> again is either a web page or a cap URL.

OK.  It sounds a little like REST.

My most immediate question then is - what has
that got to do with calculus?

> That's the basic model. I am hopeful that any web programmer will
> readily understand it. To date, I've had good success explaining the
> model on lists devoted to web programming.

Well, as written there is no reason to believe
that it will be hard to understand the actions.
There are objects you call web pages, and there
are identifiers for objects you call cap URLs.
There is an action to get an object, given its
identifier;  and an action to "do something"
with objects and/or identifiers, by sending
them to an identifier, and having that action
return either an object or an identifier.

But so far I don't see much difference between
that and a dozen prior interfaces, and in
particular I don't see why it has such a fancy
name, unless we are engaged in an exercise of
branding (no bad thing ... a priori) ?

iang