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RE: Qualities of URLs and resources

From: Larry Masinter <LM@att.com>
Date: Wed, 9 Feb 2000 20:46:30 -0800
To: "Jim Whitehead" <ejw@ics.uci.edu>
Cc: <fielding@ebuilt.com>, <w3c-dist-auth@w3.org>
Message-ID: <NDBBKEBDLFENBJCGFOIJGEAFCDAA.LM@att.com>
Roy:

> Actually, it is more like ({U,t} -R-> {V1, V2, ...}), where t is the
> current time, R is the resource, -R-> is a mapping function that has
> been implemented according to the semantics of resource R), and the range
> is a set of values representing that resource at time t.

Jim:

> So, using your notation, I would re-write the full mapping as:
> {URI1, URI2, ... URIn} -UMap-> resource -RMap-> {V1, V2, ... Vm}

> Where UMap is the URI to resource mapping function, and RMap is the
resource
> to value mapping function.  I omit time since it's really tangential to
our
> discussion, assuming that the entire set of mappings occurs at a given
time
> t.

Neither of these notations captures content negotiation, and it isn't
OK to remove 't'. The whole *point* is to understand what are
the things that are stable over time and which things can change, and how.

If you just look 'at an instant' then there's no meaningful way
of distinguishing URLs from resources, and collapsing -UMap->. I'm guessing
you want to make UMap vary more slowly and only with explicit operations
(BIND and UNBIND) while RMap encompases all of the content negotiation &
time
varying behavior of resources without having any explicit operation modify
the mapping.
Received on Wednesday, 9 February 2000 23:47:23 GMT

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