whole_func_string: function or(other) {
      return function* (source) {
          let hasYieldedItem = false;
          for (const item of source) {
              yield item;
              hasYieldedItem = true;
          }
          if (!hasYieldedItem) {
              yield* other;
          }
      };
  }
func_code_string: function or(other) {
      return function* (source) {
          let hasYieldedItem = false;
          for (const item of source) {
              yield item;
              hasYieldedItem = true;
          }
          if (!hasYieldedItem) {
              yield* other;
          }
      };
  }
func_documentation_string: Return the specified iterable if the source iterable is empty