p:pipeline

In this and the following few messages, I'm going to try to summarize
where I think we are. I'm trying (perhaps foolishly) to do this with
a slightly more abstract and compact syntax.

A pipeline looks like this:

  pipeline := ($name?, input*, output*, {body}+)

That is, it has an optional name, zero or more inputs, zero or more
outputs, and a body. The body is basically "step" but will actually be
(step|for-each|choose|...)

An input looks like this:

  input := ($name, $label, $href?, {any content})

The name/label pair form the external/internal binding for the stream.
If the API doesn't define the input, then it can be read from a URI or
taken directly from content.

An output looks like this:

  output := ($name, $from)

The name/from pair form the external/internal binding for the stream.
The from must point to the label of some in-scope (a concept not yet
clearly defined) output (e.g., the with-output on a step).

                                        Be seeing you,
                                          norm

-- 
Norman Walsh
XML Standards Architect
Sun Microsystems, Inc.