use crate::{
Consumer, Executor, Folder, ParallelIterator, Producer, ProducerCallback, Reducer, Setup,
WithProducer, WithSetup,
};
pub struct FilterMap<X, O> {
base: X,
operation: O,
}
impl<X, O> FilterMap<X, O> {
pub fn new(base: X, operation: O) -> Self {
Self { base, operation }
}
}
impl<'a, X, O, S> ParallelIterator<'a> for FilterMap<X, O>
where
X: ParallelIterator<'a>,
O: Fn(X::Item) -> Option<S> + Clone + Send + 'a,
S: Send + 'a,
{
type Item = S;
fn drive<E, C, D, R>(self, executor: E, consumer: C) -> E::Result
where
E: Executor<'a, D>,
C: Consumer<Self::Item, Result = D, Reducer = R> + 'a,
D: Send + 'a,
R: Reducer<D> + Send + 'a,
{
self.base.drive(
executor,
FilterMapConsumer {
base: consumer,
operation: self.operation,
},
)
}
}
impl<'a, X, O, S> WithProducer<'a> for FilterMap<X, O>
where
X: WithProducer<'a>,
O: Fn(X::Item) -> Option<S> + Clone + Send + 'a,
S: Send + 'a,
{
type Item = S;
fn with_producer<CB>(self, callback: CB) -> CB::Output
where
CB: ProducerCallback<'a, Self::Item>,
{
self.base.with_producer(FilterMapCallback {
base: callback,
operation: self.operation,
})
}
}
struct FilterMapConsumer<C, O> {
base: C,
operation: O,
}
impl<C, O> WithSetup for FilterMapConsumer<C, O>
where
C: WithSetup,
{
fn setup(&self) -> Setup {
self.base.setup()
}
}
impl<'a, C, O, T, S> Consumer<T> for FilterMapConsumer<C, O>
where
C: Consumer<S>,
O: Fn(T) -> Option<S> + Clone + Send,
{
type Folder = FilterMapFolder<C::Folder, O>;
type Reducer = C::Reducer;
type Result = C::Result;
fn split(self) -> (Self, Self, Self::Reducer) {
let (left, right, reducer) = self.base.split();
let left = FilterMapConsumer {
base: left,
operation: self.operation.clone(),
};
let right = FilterMapConsumer {
base: right,
operation: self.operation,
};
(left, right, reducer)
}
fn split_at(self, index: usize) -> (Self, Self, Self::Reducer) {
let (left, right, reducer) = self.base.split_at(index);
let left = FilterMapConsumer {
base: left,
operation: self.operation.clone(),
};
let right = FilterMapConsumer {
base: right,
operation: self.operation,
};
(left, right, reducer)
}
fn into_folder(self) -> Self::Folder {
FilterMapFolder {
base: self.base.into_folder(),
operation: self.operation,
}
}
fn is_full(&self) -> bool {
self.base.is_full()
}
}
struct FilterMapFolder<F, O> {
base: F,
operation: O,
}
impl<F, O, T, S> Folder<T> for FilterMapFolder<F, O>
where
F: Folder<S>,
O: Fn(T) -> Option<S> + Clone,
{
type Result = F::Result;
fn consume(mut self, item: T) -> Self {
if let Some(item) = (self.operation)(item) {
self.base = self.base.consume(item)
}
self
}
fn consume_iter<X>(mut self, iter: X) -> Self
where
X: IntoIterator<Item = T>,
{
self.base = self
.base
.consume_iter(iter.into_iter().filter_map(self.operation.clone()));
self
}
fn complete(self) -> Self::Result {
self.base.complete()
}
fn is_full(&self) -> bool {
self.base.is_full()
}
}
struct FilterMapCallback<CB, O> {
base: CB,
operation: O,
}
impl<'a, CB, O, T, S> ProducerCallback<'a, T> for FilterMapCallback<CB, O>
where
CB: ProducerCallback<'a, S>,
O: Fn(T) -> Option<S> + Clone + Send + 'a,
T: Send,
S: Send,
{
type Output = CB::Output;
fn callback<P>(self, producer: P) -> Self::Output
where
P: Producer<Item = T> + 'a,
{
self.base.callback(FilterMapProducer {
base: producer,
operation: self.operation,
})
}
}
struct FilterMapProducer<P, O> {
base: P,
operation: O,
}
impl<P, O> WithSetup for FilterMapProducer<P, O>
where
P: WithSetup,
{
fn setup(&self) -> Setup {
self.base.setup()
}
}
impl<'a, P, O, T, S> Producer for FilterMapProducer<P, O>
where
P: Producer<Item = T>,
O: Fn(T) -> Option<S> + Clone + Send,
S: Send,
{
type Item = S;
type IntoIter = std::iter::FilterMap<P::IntoIter, O>;
fn into_iter(self) -> Self::IntoIter {
self.base.into_iter().filter_map(self.operation)
}
fn split(self) -> (Self, Option<Self>) {
let operation = self.operation;
let (left, right) = self.base.split();
let left = FilterMapProducer {
base: left,
operation: operation.clone(),
};
let right = right.map(move |right| FilterMapProducer {
base: right,
operation,
});
(left, right)
}
fn fold_with<F>(self, folder: F) -> F
where
F: Folder<Self::Item>,
{
self.base
.fold_with(FilterMapFolder {
base: folder,
operation: self.operation,
})
.base
}
}