anchor.diff:        ${optionalString cfg.enableCompletion "autoload -U compinit && compinit"}
         ${optionalString cfg.enableBashCompletion "autoload -U bashcompinit && bashcompinit"}
   
  +      ${optionalString cfg.enableSyntaxHighlighting
  +        "source ${pkgs.zsh-syntax-highlighting}/share/zsh-syntax-highlighting/zsh-syntax-highlighting.zsh"
  +      }
  +
  +
         # Read system-wide modifications.
         if test -f /etc/zshrc.local; then
           . /etc/zshrc.local
  
positive.code:       description = "Enable fzf keybinding for Ctrl-r history search.";
      };
  
    };
  
    config = mkIf cfg.enable {
  
negative.code:     environment.systemPackages =
        [ # Include zsh package
          pkgs.zsh
        ] ++ optional cfg.enableCompletion pkgs.nix-zsh-completions
          ++ optional cfg.enableSyntaxHighlighting pkgs.zsh-syntax-highlighting;
  
      environment.loginShell = mkDefault "${shell}/bin/zsh -l";
      environment.variables.SHELL = mkDefault "${shell}/bin/zsh";
  