anchor.diff:  
       environment.etc."zinputrc".source = ./zinputrc;
   
  -    environment.systemPackages = [ pkgs.zsh ];
  +    environment.systemPackages = [ pkgs.zsh ]
  +      ++ optional cfg.enableCompletion pkgs.nix-zsh-completions;
   
       #users.defaultUserShell = mkDefault "/run/current-system/sw/bin/zsh";
   
  
positive.code:         type = types.lines;
        };
  
      };
  
    };
  
negative.code:         export HISTFILE=$HOME/.zsh_history
  
          setopt HIST_IGNORE_DUPS SHARE_HISTORY HIST_FCNTL_LOCK
  
          # Tell zsh how to find installed completions
          for p in ''${(z)NIX_PROFILES}; do
            fpath+=($p/share/zsh/site-functions $p/share/zsh/$ZSH_VERSION/functions)
          done
  
          ${if cfg.enableCompletion then "autoload -U compinit && compinit" else ""}
        '';
  
      };
  