Nim is an interesting language. (http://nim-lang.org). It's syntax is brief, it is compiled to 'C' or C++ or Objective C, which is then compiled to machine code - which executes very fast.
I have been learning Nim by gradually moving my Ruby programs to Nim. A typical Ruby program that executes in minutes (7), executes in seconds (1.7) when rewritten in Nim.
There is a book (also Manning) https://manning.com/books/nim-in-action
There are tools to help with wrapping external libraries so they can be used easily with Nim.
I was thinking that Sodium and Nim would make a good match.