Re: compound steps and primary inputs

On Fri, Sep 26, 2008 at 2:39 PM, Norman Walsh <ndw@nwalsh.com> wrote:
> James Garriss <james@garriss.org> writes:
>
>> I understand what a primary input port is.  What I don't know is how I know
>> that p:for-each has only one input.
>
> The single (and hence primary) input to p:for-each is spelled
> p:iteration-source (instead of p:input). Similarly, it's spelled
> p:viewport-source on viewport and p:xpath-context on p:choose/p:when.
>
> Why, you may ask, did we change the spelling in all those places? Why
> not just use p:input there? Well, the answer is, because p:input has
> all sorts of attributes (port, sequence, primary, kind) that don't
> apply in those contexts. For a long time, we tried to make p:input
> work in those places but it was hopelessly confusing.
>
> Our decision to use a different name obviously introduces some
> confusion too, but I'm pretty confident it's less confusion than if I
> had to explain why some attributes were allowed in some places and not
> others and why some attributes could only have fixed values in some
> places and not others.

this is a nice description ... I would propose paraphrasing this
somewhere in the spec ;)

J

Received on Friday, 26 September 2008 12:52:41 UTC