Thank you for this video! You helped me realize that one reason why I like datalog is because it walks the line of being expressive enough to be useful but not so much that it becomes unwieldy, and that this line closely tracks complexity theory further with certain extensions.
What a timing for a video! I've just started experimenting with my own implementation of GGP (Gerneral Game Playing) as a fun side-project and game descriptions come in Datalog inspired language GDL (the painful part is that they use ! operator for lists, so it is not possible to interpret it directly in Prolog, because you can't redefine that operator, but I digress). A lot of good theoretical information. Can you make more videos about theory of Prolog? The problem I face is that there is a lot known about Prolog but, white papers are hard to find and sometimes are very difficult for a not mathematician. For example I still don't fully understand what a fixed-point *is*.
If you have a program with unwanted ! operators in it, you can read in the program using Prolog, replace ! by something else programmatically and then evaluate it or store it as a new program.
Happy to see more videos in this series! I don't know that the argument "either syntax matters or it doesn't" holds water, though. Syntax can serve more than one objective, only one of which is prolog compatibility, and other objectives can be more important. People who argue that the syntax change doesn't make it not datalog are not arguing that syntax doesn't matter, because they changed the syntax. They are arguing that there is something more important than compatibility with prolog. "Datalog inspired" seems reasonable. But datalog implementors are under no obligation to agree that having a path to prolog is worth more than whatever else they are trying to accomplish.
AWS uses the optimized datalog solver soufflé to statically analysis network connectivity. One use is to prove security invariants like the DMZ network cannot access the management interfaces of any device.
It would be amazing if a prolog engine could dynamically evaluate the current query and automatically select the strongest execution strategy possible given the used built-ins.
About the syntax question, though I agree completely, the example of Erlang vs. Elixir shows that unfortunately Ruby-like syntax made the language much more popular ( 😭) than Prolog-like…
Yes good point! I just had a great breakfast in a very nice Viennese "Kaffeehaus", www.cafe-eiles.at/ ! I also noticed that a fastfood restaurant nearby was a lot more popular. The analogy can maybe be extended.
@@ThePowerOfProlog Well, I don't know Erlang enough… Did Elixir hurt Erlang or did it help it? I have no idea… Are they fighting against each other or do they collaborate in some sense? For Prolog/Datalog, I think that even with a bad syntax, something that would help build a larger community of users might, in some cases, be beneficial. (at least, if as you say, there is a "path" to Prolog…)
I know how to install prolog because swi is one of the defacto opensource implementations and has a homebrew package, but how do I install datalog? Where do I go? Who is/are the primary opensource developer(s)?
