This Rust code defines an asynchronous iterator trait (AsyncIterator) and its associated types and implementations. It provides a framework for transforming and processing asynchronous data streams in a composable and efficient manner.
The AsyncIterator
trait defines the core functionality for asynchronous iterators. It specifies two methods:
-
fold_folder
: Applies a fold operation to the iterator's elements using a provided Folder instance. -
async_fold
: A higher-order version offold_folder
that takes an initial value and a fold function as parameters.
The AsyncIterator
trait provides three methods for transforming and filtering the iterator's elements:
-
map
: Applies a provided function to each element and returns a new iterator containing the transformed elements. -
filter
: Filters the iterator's elements based on a provided predicate function, returning only those elements that satisfy the predicate. -
collect_vec
: Collects all the elements of the iterator into a Vec.
The Folder
trait defines the fold operation for asynchronous iterators. It takes an initial value and a fold function as input and returns an updated value. The BasicFolder
struct implements the Folder
trait and provides a default fold operation.
The MapFolder
and FilterFolder
structs specialize the Folder
trait for Map
and Filter
iterators, respectively. They apply the respective transformation or filtering logic to each element before calling the base Folder's fold operation.
The Iter
, Map
, and Filter
structs implement the AsyncIterator
trait for various types of asynchronous iterators. They handle the specific logic for iterating over and processing their respective data sources.