Re: A new "input-filter" branch

James Fuller <jim@webcomposite.com> writes:
> I like the spirit of why to include a p:filter but having trouble
> understanding it  as a child of p:input, as all the other elements at
> this level denote documents (not operations).
>
> at first I wondered if select="" can't be made to do equiv thing and
> if thats the case maybe we start there ?
>
> there maybe other considerations as well, will have a deeper think.

Romain also commented here: https://github.com/xproc/specification/issues/154

Yes, this proposal definitely mixes things in p:input. And p:filter is
probably a poor choice of names given that we already have a p:filter
step. So, imagine we'll call it something else eventually.

I was being lazy about the content model; for the sake of Romain's
question about ordering, let's force all the filters to be at the end
of the content model.

The filter element is a child of p:input because there's no where else
to put it, really. The idea is that it applies (they apply) to the
sequence of documents appearing on that input port.

Now that we have non-XML documents in the pipeline, I can imagine that
there will be more streams of "mixed" documents (contents of ZIP
files, contents of directories globbed, etc.). Some steps will want to
process only the images, some only the XML, etc. Rather than having to
filter the streams in separate steps, my thinking is that this
simplifies a common case.

It was inspired by ant and gradle features that allow you to grab a
bunch of files, because that simplifies the selection, and then
explicitly exclude some. I suppose exclude is all you really need, but
I liked the parallelism of include/exclude.

Using the select attribute on p:input only solves the very simple
case. But maybe that's enough.

(The case it doesn't handle is when you want to use @select to process
some interior portion of the documents because then you can't (easily)
make @select do both.)

                                        Be seeing you,
                                          norm

-- 
Norman Walsh
Lead Engineer
MarkLogic Corporation
Phone: +1 512 761 6676
www.marklogic.com