- From now on a pipeline context is always a dictionary. Simple is better than complex.
- a pipeline step's def run_step(context) used to require a return type `return context`. This is a hang-over from the early days of pypyr where I was still thinking that a context could by anything - a plain old string, or a dictionary, or a stream (file-like objects in pythonese), or a whatever.
- So if the `run_step(context)` was to be an immutable type (e.g a string), then any alterations to the context inside the run_step wouldn't have made it back out of the func unless explicitly returned as a new obj `return mymanipulatedblah`. Hence the 1st design with the explicit return required.
- Given the heavy preponderance of mutable dictionary usage for the context for pretty much everything, and given that the dictionary-like context can contain any of the different types listed above (plain old string, dictionary containing dictionaries, dictionary containing lists, or file-like objs), I'm having a hard-time justifying the extra effort to deal with the vague theory that "just maybe" someone just wants to use a plain string as a context for the entire pipeline beginning to end.
- It also feels gnarly for the end-user to have to remember to have a return context at the end of his custom pipeline step code. There should be one-- and preferably only one --obvious way to do it.