That is a generally-useful property in various contexts, such as user-defined stream-processing functions running on shared systems. Long ago my main contribut

That is a generally-useful property in various contexts, such as user-defined stream-processing functions running on shared systems. Long ago my main contribution to the re-write of the "Liverpool sort program" for processing nuclear physics data tapes was ensuring that the DSL wasn't Turing complete, to ensure progress would be made.