Comment by daxfohl

Going a little further, what I'd really like to see is the core concepts implemented in a way that allows a standard implementation to follow straightforwardly from the type system, but also allow for doing nonstandard things. Like, "here's a logic language built in" is kind of boring. What's more enticing is "Here are the components. Here's a nominal implementation based on these components. Here's a weird thing you can do that we hadn't actually designed for, but could fit certain use cases."

I remember Jon Skeet did a whole series of blog posts on reimplementing C# async, which was possible because C#'s async syntax isn't bolted to the implementation, and added features like coroutines that weren't part of C# at all. https://codeblog.jonskeet.uk/2011/06/22/eduasync-part-13-fir.... Similarly Daniel Earwicker had a series where he implemented async/await using iterator syntax instead https://smellegantcode.wordpress.com/2010/12/14/unification-....

And sure, now I know it's all kind of fancy but fairly trivial stuff you can do with monads (and I guess free monads in the Linq-to-SQL case), but it was fascinating to me at the time.

So yeah, for "selling" purposes, I think rather than selling datalog built into the language as a front-page feature, a series of "how to build a datalog" posts would go further in showing off the power of the components of the language that it's built from.

(And FWIW I do like the way C# has built-in support for "important" monads like iterators (foreach), generators (yield), async (await), optional (null propagation operators), etc., even though a language purist would argue against it. I think it provides an easier on-ramp for newer developers, and helps make common things more concise and readable. So it'd be interesting to see where that line would best get drawn for logic programming, what gets special-but-extensible syntax support, and what is purely implementation and functions).