Struct specs::JoinParIter

#[must_use]
pub struct JoinParIter<J>(_);

JoinParIter is a ParallelIterator over a group of Storages.

Trait Implementations

impl<J> ParallelIterator for JoinParIter<J> where
    J: Join + Send,
    J::Mask: Send + Sync,
    J::Type: Send,
    J::Value: Send, 

type Item = J::Type

fn drive_unindexed<C>(self, consumer: C) -> C::Result where
    C: UnindexedConsumer<Self::Item>, 

Internal method used to define the behavior of this parallel iterator. You should not need to call this directly.

fn weight(self, _scale: f64) -> Weight<Self>

Deprecated since v0.7.0

: try with_min_len or with_max_len instead

Deprecated. If the adaptive algorithms don't split appropriately, try IndexedParallelIterator::with_min_len() or with_max_len() instead.

fn weight_max(self) -> Weight<Self>

Deprecated since v0.7.0

: try with_min_len or with_max_len instead

Deprecated. If the adaptive algorithms don't split appropriately, try IndexedParallelIterator::with_min_len() or with_max_len() instead.

fn for_each<OP>(self, op: OP) where
    OP: Fn(Self::Item) -> () + Sync, 

Executes OP on each item produced by the iterator, in parallel.

fn count(self) -> usize

Counts the number of items in this parallel iterator.

fn map<F, R>(self, map_op: F) -> Map<Self, MapFn<F>> where
    F: Fn(Self::Item) -> R + Sync,
    R: Send, 

Applies map_op to each item of this iterator, producing a new iterator with the results.

fn cloned<'a, T>(self) -> Map<Self, MapCloned> where
    Self: ParallelIterator<Item = &'a T>,
    T: 'a + Clone + Send, 

Creates an iterator which clones all of its elements. This may be useful when you have an iterator over &T, but you need T.

fn inspect<OP>(self, inspect_op: OP) -> Map<Self, MapInspect<OP>> where
    OP: Fn(&Self::Item) -> () + Sync, 

Applies inspect_op to a reference to each item of this iterator, producing a new iterator passing through the original items. This is often useful for debugging to see what's happening in iterator stages.

fn filter<P>(self, filter_op: P) -> Filter<Self, P> where
    P: Fn(&Self::Item) -> bool + Sync, 

Applies filter_op to each item of this iterator, producing a new iterator with only the items that gave true results.

fn filter_map<P, R>(self, filter_op: P) -> FilterMap<Self, P> where
    P: Fn(Self::Item) -> Option<R> + Sync,
    R: Send, 

Applies filter_op to each item of this iterator to get an Option, producing a new iterator with only the items from Some results.

fn flat_map<F, PI>(self, map_op: F) -> FlatMap<Self, F> where
    F: Fn(Self::Item) -> PI + Sync,
    PI: IntoParallelIterator, 

Applies map_op to each item of this iterator to get nested iterators, producing a new iterator that flattens these back into one.

fn reduce<OP, ID>(self, identity: ID, op: OP) -> Self::Item where
    ID: Fn() -> Self::Item + Sync,
    OP: Fn(Self::Item, Self::Item) -> Self::Item + Sync, 

Reduces the items in the iterator into one item using op. The argument identity should be a closure that can produce "identity" value which may be inserted into the sequence as needed to create opportunities for parallel execution. So, for example, if you are doing a summation, then identity() ought to produce something that represents the zero for your type (but consider just calling sum() in that case).

fn reduce_with<OP>(self, op: OP) -> Option<Self::Item> where
    OP: Fn(Self::Item, Self::Item) -> Self::Item + Sync, 

Reduces the items in the iterator into one item using op. If the iterator is empty, None is returned; otherwise, Some is returned.

fn reduce_with_identity<OP>(self, identity: Self::Item, op: OP) -> Self::Item where
    OP: Fn(Self::Item, Self::Item) -> Self::Item + Sync,
    Self::Item: Clone,
    Self::Item: Sync, 

Deprecated since v0.5.0

: call reduce instead

Deprecated. Use reduce() instead.

fn fold<T, ID, F>(self, identity: ID, fold_op: F) -> Fold<Self, ID, F> where
    F: Fn(T, Self::Item) -> T + Sync,
    ID: Fn() -> T + Sync,
    T: Send, 

Parallel fold is similar to sequential fold except that the sequence of items may be subdivided before it is folded. Consider a list of numbers like 22 3 77 89 46. If you used sequential fold to add them (fold(0, |a,b| a+b), you would wind up first adding 0 + 22, then 22 + 3, then 25 + 77, and so forth. The parallel fold works similarly except that it first breaks up your list into sublists, and hence instead of yielding up a single sum at the end, it yields up multiple sums. The number of results is nondeterministic, as is the point where the breaks occur.

fn sum<S>(self) -> S where
    S: Send + Sum<Self::Item> + Sum<S>, 

Sums up the items in the iterator.

fn product<P>(self) -> P where
    P: Send + Product<Self::Item> + Product<P>, 

Multiplies all the items in the iterator.

fn mul(self) -> Self::Item where
    Self::Item: Product<Self::Item>, 

Deprecated since v0.6.0

: name changed to product() to match sequential iterators

DEPRECATED

fn min(self) -> Option<Self::Item> where
    Self::Item: Ord, 

Computes the minimum of all the items in the iterator. If the iterator is empty, None is returned; otherwise, Some(min) is returned.

fn min_by_key<K, F>(self, f: F) -> Option<Self::Item> where
    F: Sync + Fn(&Self::Item) -> K,
    K: Ord + Send, 

Computes the item that yields the minimum value for the given function. If the iterator is empty, None is returned; otherwise, Some(item) is returned.

fn max(self) -> Option<Self::Item> where
    Self::Item: Ord, 

Computes the maximum of all the items in the iterator. If the iterator is empty, None is returned; otherwise, Some(max) is returned.

fn max_by_key<K, F>(self, f: F) -> Option<Self::Item> where
    F: Sync + Fn(&Self::Item) -> K,
    K: Ord + Send, 

Computes the item that yields the maximum value for the given function. If the iterator is empty, None is returned; otherwise, Some(item) is returned.

fn chain<C>(self, chain: C) -> Chain<Self, <C as IntoParallelIterator>::Iter> where
    C: IntoParallelIterator<Item = Self::Item>, 

Takes two iterators and creates a new iterator over both.

fn find_any<P>(self, predicate: P) -> Option<Self::Item> where
    P: Fn(&Self::Item) -> bool + Sync, 

Searches for some item in the parallel iterator that matches the given predicate and returns it. This operation is similar to [find on sequential iterators][find] but the item returned may not be the first one in the parallel sequence which matches, since we search the entire sequence in parallel.

fn find_first<P>(self, predicate: P) -> Option<Self::Item> where
    P: Fn(&Self::Item) -> bool + Sync, 

Searches for the first item in the parallel iterator that matches the given predicate and returns it.

fn find_last<P>(self, predicate: P) -> Option<Self::Item> where
    P: Fn(&Self::Item) -> bool + Sync, 

Searches for the last item in the parallel iterator that matches the given predicate and returns it.

fn any<P>(self, predicate: P) -> bool where
    P: Fn(Self::Item) -> bool + Sync, 

Searches for some item in the parallel iterator that matches the given predicate, and if so returns true. Once a match is found, we'll attempt to stop process the rest of the items. Proving that there's no match, returning false, does require visiting every item.

fn all<P>(self, predicate: P) -> bool where
    P: Fn(Self::Item) -> bool + Sync, 

Tests that every item in the parallel iterator matches the given predicate, and if so returns true. If a counter-example is found, we'll attempt to stop processing more items, then return false.

fn collect<C>(self) -> C where
    C: FromParallelIterator<Self::Item>, 

Create a fresh collection containing all the element produced by this parallel iterator.

fn opt_len(&mut self) -> Option<usize>

Internal method used to define the behavior of this parallel iterator. You should not need to call this directly.