I mean... Nix satisfies every single one of what you mentioned and people say its too complicated. It's literally just the JSON data structure with lambdas, which really is basic knowledge for any computer scientist, and yet people complain about it.
It's fairly straightforward to 'embed' and as a bonus it generates json anyway (you can use the Nix command line to generate JSON). Me personally, I use it as my templating system (independent of nixpkgs) and it works great. It's a real language, but also restrictive enough that you don't do anything stupid (no IO really, and the IO it does have is declarative, functional and pure -- via hashing).
3. Turing complete and based on the lambda calculus so has access to the full suite of functional control structures. Also has basic if/then/else statements for the most common cases and for intuition.
4. no threading, no concurrency, no real IO
5. definitely not object-oriented and no inheritance
6. It is functional in design and has an extremely thin set of builtins
7. FFI model is either embed libnix directly (this does not require embedding the nix store stuff, which is a completely separate modular system), or use the command line to generate json (nix-instantiate --eval --json).
Note: do not confuse nixpkgs and NixOS with the nix language. The former is a system to build linux packages and entire linux distributions that use the latter as a configuration language. The nix language is completely independent and can be used for whatever.
Tried to use Nix as a homebrew replacement and failed to get it installed correctly with it blowing up with crazy error messages that I couldn't google. I didn't even get to the point of assessing the language. It really seems like the right kind of idea, but it doesn't seem particularly stable or easy enough to get to that initial payoff. If there's a nice language under there it is crippled by the fact that the average user is going to have a hard time getting to it.
You can use nix without using nixpkgs (you seemed to be trying to use nixpkgs). The nix language is accessible via several command line tools, nix repl, nix eval, nix-instantiate, etc, and can emit json via everal flags, as well as a builtin function.
I agree with the point's in Nix's favor except for 2. dynamically typed. Defining structs as part of the language would be nice. In fact, type checking is done ad-hoc now by passing data through type checking functions.
It's fairly straightforward to 'embed' and as a bonus it generates json anyway (you can use the Nix command line to generate JSON). Me personally, I use it as my templating system (independent of nixpkgs) and it works great. It's a real language, but also restrictive enough that you don't do anything stupid (no IO really, and the IO it does have is declarative, functional and pure -- via hashing).
In Nix's favor:
1. Can be described in a one page flier. An in-depth exhaustive explanation of the language's features is a few pages (https://nixos.org/manual/nix/stable/language/)
2. dynamically typed
3. Turing complete and based on the lambda calculus so has access to the full suite of functional control structures. Also has basic if/then/else statements for the most common cases and for intuition.
4. no threading, no concurrency, no real IO
5. definitely not object-oriented and no inheritance
6. It is functional in design and has an extremely thin set of builtins
7. FFI model is either embed libnix directly (this does not require embedding the nix store stuff, which is a completely separate modular system), or use the command line to generate json (nix-instantiate --eval --json).
Note: do not confuse nixpkgs and NixOS with the nix language. The former is a system to build linux packages and entire linux distributions that use the latter as a configuration language. The nix language is completely independent and can be used for whatever.