pub trait Consumer<Item>: Send + Sized {
type Folder: Folder<Item, Result = Self::Result>;
type Reducer: Reducer<Self::Result>;
type Result: Send;
fn split_at(self, index: usize) -> (Self, Self, Self::Reducer);
fn into_folder(self) -> Self::Folder;
fn full(&self) -> bool;
}
Expand description
A consumer is effectively a generalized “fold” operation,
and in fact each consumer will eventually be converted into a
Folder
. What makes a consumer special is that, like a
Producer
, it can be split into multiple consumers using
the split_at
method. When a consumer is split, it produces two
consumers, as well as a reducer. The two consumers can be fed
items independently, and when they are done the reducer is used to
combine their two results into one. See the plumbing
README for further details.
Required Associated Types
sourcetype Folder: Folder<Item, Result = Self::Result>
type Folder: Folder<Item, Result = Self::Result>
The type of folder that this consumer can be converted into.
Required Methods
sourcefn split_at(self, index: usize) -> (Self, Self, Self::Reducer)
fn split_at(self, index: usize) -> (Self, Self, Self::Reducer)
Divide the consumer into two consumers, one processing items
0..index
and one processing items from index..
. Also
produces a reducer that can be used to reduce the results at
the end.
sourcefn into_folder(self) -> Self::Folder
fn into_folder(self) -> Self::Folder
Convert the consumer into a folder that can consume items sequentially, eventually producing a final result.