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RE: Do pipelines have ports?

From: <Toman_Vojtech@emc.com>
Date: Fri, 19 Sep 2008 08:53:14 -0400
Message-ID: <6E216CCE0679B5489A61125D0EFEC7870CAA80E0@CORPUSMX10A.corp.emc.com>
To: <xproc-dev@w3.org>
What about this (see Section 4.1, p:pipeline):
"The p:pipeline element is just a simplified form of step declaration. A
document that reads:
<p:pipeline some-attributes>
can be interpreted as if it read:
<p:declare-step some-attributes>
  <p:input port='source' primary='true'/>
  <p:input port='parameters' kind='parameters' primary='true'/>
  <p:output port='result' primary='true'>
See p:declare-step for more details."


	From: xproc-dev-request@w3.org [mailto:xproc-dev-request@w3.org]
On Behalf Of James Garriss
	Sent: Friday, September 19, 2008 2:42 PM
	To: XProc Dev
	Subject: Re: Do pipelines have ports?
	In 2:1:  Steps have "ports" into which inputs and outputs are
	In 2:2:  The input ports declared on a step are its declared
	In 2:3:  Each step may have one input port designated as the
primary input port and one output port designated as the primary output
	In 2:4:  Steps are connected together by their input ports and
output ports.
	In 5:1:  A p:input identifies an input port for a step.
	It's pretty clear that steps have ports.  It's not so clear (at
least to me) that pipelines have ports (hence my question below).  Now
it's certainly clear that pipelines have inputs/outputs, but once the WD
starts talking about ports (in the middle of 2:1), it only refers to
steps having ports.  Maybe it should be more clear that pipelines also
have ports?
	The closest thing I have found is this, an indirect reference in
section 2:  A pipeline is a set of connected steps, with outputs of one
step flowing into inputs of another.] A pipeline is itself a step. 
	Thanks for your help, Jeni!
	James Garriss

	From: Jeni Tennison <jeni@jenitennison.com>
	Date: Thu, 18 Sep 2008 22:02:12 +0100
	To: James Garriss <james@garriss.org>
	Cc: XProc Dev <xproc-dev@w3.org>
	Subject: Re: Do pipelines have ports?
	> Is it correct to say that pipelines have ports as well, given
	> example such as this?
	> <p:declare-step xmlns:p="http://www.w3.org/ns/xproc">
	>     <p:input port="source">
	>         <p:document href="BookStore.xml"/>
	>     </p:input>
	>     <p:output port="result"/>
	>     <p:identity/>
	> </p:declare-step>
	> If not, what do you call them?
	Absolutely. And if you ever give that step a type, then you can
	it as a step in another pipeline in exactly the same way you can
	built-in steps.
	Jeni Tennison
Received on Friday, 19 September 2008 12:54:57 UTC

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