transducer

Composable algorithmic transformations. Transducers let you combine reduction operations like `map`, `filter`, `take_while`, `take`, and so on into a single reducing function. As with Stream, but in contrast to Enum, all operations are performed for each item before the next item in the enumerable is processed. One difference with the Stream module is that the transducers' reducing functions don't have to produce an enumerable, while Stream module transformations always do.