Re: ACTION A-227-01 (Variable shadowing)

"Toman, Vojtech" <vojtech.toman@emc.com> writes:
> I would say that an (p:)option cannot shadow another
> (p:)option/(p:)variable, but that (p:)variable can shadow both
> (p:)option and (p:)variable.

Why the distinction?

> Also note a small problem with the current wording ("its scope
> consists of the sibling elements that follow its declaration and the
> descendants of those siblings") and p:option. Consider the following
> pipeline:
>
> <p:pipeline>
>   <p:option name="opt"/>
>   <p:pipeline type="...">
>     <p:option name="opt"/>
>     ...
>   </p:pipeline>
>   ...
> </p:pipeline>

We have special rules for p:pipeline:

  Irrespective of the context in which the p:declare-step occurs,
  there are initially no option or variable names in-scope inside a
  p:declare-step. That is, p:option and p:variable elements can refer
  to values declared by their preceding siblings, but not by any of
  their ancestors.

I don't think option shadowing is really a thing because there are no
compound steps with options. This is the canonical example, I think:

<p:pipeline>
  <p:option name="opt"/>
  <p:group>
    <p:variable name="opt"/>
    ...
  </p:group>
  ...
</p:pipeline>

> The nested p:pipeline (sibling of the p:option) has a descendant
> p:option with the same option name. Obviously, this should work just
> fine as there is no shadowing in this case, but one might get the
> impression that this is not allowed.

I thought this erratum was clear:

http://www.w3.org/XML/XProc/docs/xproc-proposed-errata.html#e-13

But I could be wrong.

                                        Be seeing you,
                                          norm

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