anchor.diff:  
       # Haskell
       cabal-install
  -    ghc
       stack
   
       # FIXME: Io
  
positive.code:     pointfree
      pointful
      # FIXME: purescript
      titlecase
    ]) ++ (with pkgs.nodePackages; [
      # aglio
      diff-so-fancy
  
negative.code:   ]) ++ (with pkgs.haskellPackages; [
      Agda
      cabal2nix
      ghc
      hpack
      idris
      # intero
  