processing steps every time

in section 2 Pipeline Concepts it states;

'The result of evaluating a pipeline (or subpipeline) is the result of
evaluating the steps that it contains, in an order consistent with the
connections between them. A pipeline must behave as if it evaluated
each step each time it occurs. Unless otherwise indicated,
implementations must not assume that steps are functional (that is,
that their outputs depend only on their inputs, options, and
parameters) or side-effect free.'

wondering if this is too limiting a paragraph with respect to possible
future optimizations ... for example, does the above term 'evaluated'
include simplifying a multi-container step to a container step, when
static analysis reveals that a certain logic branch (e.g. xpath
condition) is never satisfied.

cheers, Jim Fuller

Received on Friday, 2 May 2008 09:18:01 UTC