/**
  Modular function type
*/
{ config, ... }:
{
  options = {
    input-type = mkOption {
      type = deferredModule;
    };
    output-type = mkOption {
      type = deferredModule;
    };
    function-type = mkOption {
      type = optionType;
      readOnly = true;
      default = functionTo (
        submodule (function: {
          options = {
            input = mkOption {
              type = submodule config.input-type;
            };
            output = mkOption {
              type = submodule config.output-type;
            };
          };
        })
      );
    };
  };
}