Re: Detecting errors

On Thu, Oct 9, 2008 at 8:14 AM, Norman Walsh <ndw@nwalsh.com> wrote:

> Consider the following pipeline:
>
> <p:declare-step name="main" ...>
>  <p:input port="source"/>
>  <p:output port="source"/>
>
>  <p:declare-step type="px:unused">
>    <p:input port="source"/>
>    <p:output port="source"/>
>    <px:undeclared/>
>  </p:declarestep>
>
>  <p:identity/>
> </p:declare-step>
>
> (a) Does this pipeline contain an error?
> (b) Are implementations allowed to report it?
> (c) Are implementations required to report it?
>

I think the answer to both is no. There is no static error that can catch
this, and the only dynamic error that comes close is XD0017 ("It is a
dynamic error if the running pipeline attempts to invoke a step which the
processor does not know how to perform."). In this case, however, the
running pipeline does not attempt to invoke the declared step that contains
the undeclared step (I assume that is what you intended by naming the step
"px:unused") - so no error occurs.

There is no error to report, so it is not required nor allowed.

Cheers,
Josh Matthews