- From: Norman Walsh <ndw@nwalsh.com>
- Date: Fri, 25 Jan 2008 10:31:46 -0500
- To: public-xml-processing-model-comments@w3.org
- Message-ID: <m2ir1hncpp.fsf@nwalsh.com>
Overtaken by events, I believe.
/ Richard Tobin <richard@inf.ed.ac.uk> was heard to say:
| The defaulted output port of a subpipeline is given the name "result".
| And the defaulted input and output ports of a pipeline (if we keep them)
| are given the names "source" and "result".
|
| Since the purpose of these is to simplify the very basic case of
| straight-line pipelines, wouldn't it be better for them to have
| unusable names such as "!result"? As it is, you can have explicit
| references to a port which is not declared. This is not only bad
| for readability, but makes it more complicated to analyse. Consider:
|
| <p:group name="g0">
|
| <p:group name="g1">
| <p:identity>
| <p:input><p:pipe step="g2" port="result"/></p:input>
| </p:identity>
| ...
| </p:group>
|
| <p:group name="g2">
| ...
| </p:group>
|
| <p:group>
|
| To determine that g0 doesn't get a defaulted output, you have to
| discover that g2's defaulted output is read in g1. But when you
| process g1, you may not have determined that g2 has a defaulted output
| yet. This is not impossible to solve, but it's another unexpected
| constraint on the order you have to analyse the program in.
|
| -- Richard
Be seeing you,
norm
--
Norman Walsh <ndw@nwalsh.com> | We have fewer friends than we imagine,
http://nwalsh.com/ | but more than we know.--Hugo Von
| Hofmannsthal
Received on Friday, 25 January 2008 15:32:20 UTC