with import <nixpkgs> { }; 
rec {
  made_it = "it is done";
}

#Further reading

#Nix by example - Part 1 : https://medium.com/@MrJamesFisher/nix-by-example-a0063a1a4c55
#Parse trees, evaluation order, composite data-types, laziness, conditionals, Let expressions, and much more...

#Luca Bruno's nix pill(s) : http://lethalman.blogspot.de/2014/07/nix-pill-1-why-you-should-give-it-try.html
#The Nix Pills are a wonderful introduction into Nix programming and you will have much joy reading them!

#NixPkgs manual : https://nixos.org/nixpkgs/manual
#Covers topics as: buildPhases, override(s) and support for specific programming languages

#NixOS Wiki : https://nixos.org/wiki/Main_Page
#The Wiki contains a lot of practical articles, like the Cheatsheet