The discussion of grouped lifetimes reminds me of the principles of Flow-based programming (without the visual part), where one main idea is that only one proce

The discussion of grouped lifetimes reminds me of the principles of Flow-based programming (without the visual part), where one main idea is that only one process owns a data packet (IP) at a time. My own experience coding in this style [1] has been extremely reassuring. You can generally really safely consider only the context of each process at a time, since there aren't even any function calls between processes, only data sharing. This meant for example that I could port a PHP application that I had been coding on for years, fighting bugs all over, into a flow-based Go application in two weeks, with a perfectly development time perfectly linear to the number of processes. I just coded each processes in the pipeline one by one, tested them and continued with the next. There were never any surprises as the application grew, as the interactions between the processes are just simple data sharing which can't really cause that much trouble. This is of course a radically different way of thinking and designing programs, but it really holds some enormous benefits. https://github.com/rdfio/rdf2smw/blob/master/main.go#L58-L150 https://github.com/rdfio/rdf2smw/blob/master/main.go#L58-L15...