The type for objects satisfying the IteratorResult interface.

result_done r is true iff r has a done property and its value is true.

result_value r is the value property of r (if any). This may only be None if result_done r is true.

get_result_value r is the value property of r. This should always be well defined as long as result_done r is false.

The type for objects satisfying the iterator protocol.

iterable v is v's iterator object (if any) looked up according to the iterable protocol.

iterator jv is Option.get (iterable jv).

next it is the next result of iterator it.

fold of_jv f it folds f over the results provided by it and converted with of_jv until one is done. The return value of the iterator is ignored.

fold_bindings is like fold except it assumes the iterator values are two-element arrays whose values are directly given to f in order. The return value of the iterator is ignored.