I’m confused by why `completion-table-with-cache’ needs to test:
(string-prefix-p last-arg arg ignore-case)
This was designef for completion-tables in general (rather than only those used in a particular kind of situation). Furthermore, even a single M-TAB completion may easily query the completion table several times with different prefix strings (because of `completion-styles`).
Thanks, I get it. Since iPython’s suggestions will never change for the same line of input, perhaps caching them “once and forever” in a given collection function will be OK. This presumes of course that none of the possible cases for long term use of a collection function will operate on distinct lines of input. I need to work out some issues on iPython’s completer backend; will revisit once that’s working well.