Constant Inputs during Iteration

For both the 'viewport' and 'foreach' step containers, I think
we need a simple statement in the document that says that inputs
consumed by steps that aren't the subject of the iteration are
consider "constant" during the iteration.  Contained steps
should receive the same document for each iteration.

Further, I think we should say that non-iteration constructs
(e.g. pipeline, group, choose) are actually considered just a single
iteration of the container.  That way the same statement applies
and inputs are considered constant during execution.  Obviously,
we'll have to avoid calling them 'non-iteration' so that we
don't have a contradiction in terms.

This all means that static resources (e.g. those pointed to with
an 'href') can't change during pipeline execution and be
considered as part of the computation.

All this is to avoid unpredictable results because a
result or resource changed during execution and to state
clearly what happens to inputs from outside for the
step container 'for-each' and 'viewport'.

--Alex Milowski

Received on Monday, 2 October 2006 16:08:03 UTC