Hands-On Software Engineering with Golang

Stageless pipelines – is that even possible?

Should a pipeline definition include a minimum number of stages for it to be considered as valid? More specifically, should we be allowed to define a pipeline with zero stages? In my view, stages should be considered as an optional part of a pipeline definition. Remember that for a pipeline to function, it requires, at minimum, an input source and an output sink.

If we were to directly connect the input to the output and execute the pipeline, we would get the same result as if we had executed a pipeline with just a single stage whose Processor is an identity function—that is, a function that always outputs the value passed to it as input. We could easily define such a function using the ProcessorFunc ...