Am 26.09.2015 um 16:49 schrieb Gianfranco Costamagna:
Thanks for this hint, and Gianfranco, also thanks for your answer, especially the link. I should have stated more precisely that setop shall be a command line tool. Python sets and combine are interesting but not as much universal as I plan my program to be.well, I fail to understand a system where python is not available, but well if you want bash I can't complain Just I don't think the final usage of the tool will be the example you provided, so I guess python might be the best way to script some easy programming.
I don’t want python to be not available. The examples you and others provided just look like “scripting in a special language”. Python and LISP are nice and probably mighty, but not universal for processing streams.
Here are other examples: <http://webusers.imj-prg.fr/~jean.michel/gap3/htm/chap028.htm> <https://www.gnu.org/software/octave/doc/interpreter/Set-Operations.html>I had to use these when I needed set operations. There must be a better solution.
but if you want to write it, nobody can stop you, and if it is good enough you will even find a sponsor eventually :)
I am going to do so and hoping for support when it’s ready.