| use super::plumbing::*; |
| use super::*; |
| |
| use std::fmt::{self, Debug}; |
| use std::iter; |
| |
| /// `Map` is an iterator that transforms the elements of an underlying iterator. |
| /// |
| /// This struct is created by the [`map()`] method on [`ParallelIterator`] |
| /// |
| /// [`map()`]: trait.ParallelIterator.html#method.map |
| /// [`ParallelIterator`]: trait.ParallelIterator.html |
| #[must_use = "iterator adaptors are lazy and do nothing unless consumed"] |
| #[derive(Clone)] |
| pub struct Map<I: ParallelIterator, F> { |
| base: I, |
| map_op: F, |
| } |
| |
| impl<I: ParallelIterator + Debug, F> Debug for Map<I, F> { |
| fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { |
| f.debug_struct("Map").field("base", &self.base).finish() |
| } |
| } |
| |
| /// Create a new `Map` iterator. |
| /// |
| /// NB: a free fn because it is NOT part of the end-user API. |
| pub fn new<I, F>(base: I, map_op: F) -> Map<I, F> |
| where |
| I: ParallelIterator, |
| { |
| Map { |
| base: base, |
| map_op: map_op, |
| } |
| } |
| |
| impl<I, F, R> ParallelIterator for Map<I, F> |
| where |
| I: ParallelIterator, |
| F: Fn(I::Item) -> R + Sync + Send, |
| R: Send, |
| { |
| type Item = F::Output; |
| |
| fn drive_unindexed<C>(self, consumer: C) -> C::Result |
| where |
| C: UnindexedConsumer<Self::Item>, |
| { |
| let consumer1 = MapConsumer::new(consumer, &self.map_op); |
| self.base.drive_unindexed(consumer1) |
| } |
| |
| fn opt_len(&self) -> Option<usize> { |
| self.base.opt_len() |
| } |
| } |
| |
| impl<I, F, R> IndexedParallelIterator for Map<I, F> |
| where |
| I: IndexedParallelIterator, |
| F: Fn(I::Item) -> R + Sync + Send, |
| R: Send, |
| { |
| fn drive<C>(self, consumer: C) -> C::Result |
| where |
| C: Consumer<Self::Item>, |
| { |
| let consumer1 = MapConsumer::new(consumer, &self.map_op); |
| self.base.drive(consumer1) |
| } |
| |
| fn len(&self) -> usize { |
| self.base.len() |
| } |
| |
| fn with_producer<CB>(self, callback: CB) -> CB::Output |
| where |
| CB: ProducerCallback<Self::Item>, |
| { |
| return self.base.with_producer(Callback { |
| callback: callback, |
| map_op: self.map_op, |
| }); |
| |
| struct Callback<CB, F> { |
| callback: CB, |
| map_op: F, |
| } |
| |
| impl<T, F, R, CB> ProducerCallback<T> for Callback<CB, F> |
| where |
| CB: ProducerCallback<R>, |
| F: Fn(T) -> R + Sync, |
| R: Send, |
| { |
| type Output = CB::Output; |
| |
| fn callback<P>(self, base: P) -> CB::Output |
| where |
| P: Producer<Item = T>, |
| { |
| let producer = MapProducer { |
| base: base, |
| map_op: &self.map_op, |
| }; |
| self.callback.callback(producer) |
| } |
| } |
| } |
| } |
| |
| /// //////////////////////////////////////////////////////////////////////// |
| |
| struct MapProducer<'f, P, F: 'f> { |
| base: P, |
| map_op: &'f F, |
| } |
| |
| impl<'f, P, F, R> Producer for MapProducer<'f, P, F> |
| where |
| P: Producer, |
| F: Fn(P::Item) -> R + Sync, |
| R: Send, |
| { |
| type Item = F::Output; |
| type IntoIter = iter::Map<P::IntoIter, &'f F>; |
| |
| fn into_iter(self) -> Self::IntoIter { |
| self.base.into_iter().map(self.map_op) |
| } |
| |
| fn min_len(&self) -> usize { |
| self.base.min_len() |
| } |
| fn max_len(&self) -> usize { |
| self.base.max_len() |
| } |
| |
| fn split_at(self, index: usize) -> (Self, Self) { |
| let (left, right) = self.base.split_at(index); |
| ( |
| MapProducer { |
| base: left, |
| map_op: self.map_op, |
| }, |
| MapProducer { |
| base: right, |
| map_op: self.map_op, |
| }, |
| ) |
| } |
| |
| fn fold_with<G>(self, folder: G) -> G |
| where |
| G: Folder<Self::Item>, |
| { |
| let folder1 = MapFolder { |
| base: folder, |
| map_op: self.map_op, |
| }; |
| self.base.fold_with(folder1).base |
| } |
| } |
| |
| /// //////////////////////////////////////////////////////////////////////// |
| /// Consumer implementation |
| |
| struct MapConsumer<'f, C, F: 'f> { |
| base: C, |
| map_op: &'f F, |
| } |
| |
| impl<'f, C, F> MapConsumer<'f, C, F> { |
| fn new(base: C, map_op: &'f F) -> Self { |
| MapConsumer { |
| base: base, |
| map_op: map_op, |
| } |
| } |
| } |
| |
| impl<'f, T, R, C, F> Consumer<T> for MapConsumer<'f, C, F> |
| where |
| C: Consumer<F::Output>, |
| F: Fn(T) -> R + Sync, |
| R: Send, |
| { |
| type Folder = MapFolder<'f, C::Folder, F>; |
| type Reducer = C::Reducer; |
| type Result = C::Result; |
| |
| fn split_at(self, index: usize) -> (Self, Self, Self::Reducer) { |
| let (left, right, reducer) = self.base.split_at(index); |
| ( |
| MapConsumer::new(left, self.map_op), |
| MapConsumer::new(right, self.map_op), |
| reducer, |
| ) |
| } |
| |
| fn into_folder(self) -> Self::Folder { |
| MapFolder { |
| base: self.base.into_folder(), |
| map_op: self.map_op, |
| } |
| } |
| |
| fn full(&self) -> bool { |
| self.base.full() |
| } |
| } |
| |
| impl<'f, T, R, C, F> UnindexedConsumer<T> for MapConsumer<'f, C, F> |
| where |
| C: UnindexedConsumer<F::Output>, |
| F: Fn(T) -> R + Sync, |
| R: Send, |
| { |
| fn split_off_left(&self) -> Self { |
| MapConsumer::new(self.base.split_off_left(), &self.map_op) |
| } |
| |
| fn to_reducer(&self) -> Self::Reducer { |
| self.base.to_reducer() |
| } |
| } |
| |
| struct MapFolder<'f, C, F: 'f> { |
| base: C, |
| map_op: &'f F, |
| } |
| |
| impl<'f, T, R, C, F> Folder<T> for MapFolder<'f, C, F> |
| where |
| C: Folder<F::Output>, |
| F: Fn(T) -> R, |
| { |
| type Result = C::Result; |
| |
| fn consume(self, item: T) -> Self { |
| let mapped_item = (self.map_op)(item); |
| MapFolder { |
| base: self.base.consume(mapped_item), |
| map_op: self.map_op, |
| } |
| } |
| |
| fn complete(self) -> C::Result { |
| self.base.complete() |
| } |
| |
| fn full(&self) -> bool { |
| self.base.full() |
| } |
| } |