class Predicate
  class Renamer < Sexpr::Rewriter

    grammar Grammar

    def on_identifier(sexpr)
      return sexpr unless new_name = options[:renaming][sexpr.name]
      return new_name if Sexpr===new_name
      [:identifier, new_name]
    end

    def on_qualified_identifier(sexpr)
      return sexpr unless new_name = options[:renaming][sexpr.name]
      return new_name if Sexpr===new_name
      [:qualified_identifier, sexpr.qualifier, new_name]
    end

    def on_native(sexpr)
      raise NotSupportedError
    end

    def on_var(sexpr)
      raise NotSupportedError
    end

    alias :on_missing :copy_and_apply

  end
end