Trait differential_dataflow::operators::count::CountTotal

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pub trait CountTotal<G: Scope, K: ExchangeData, R: Semigroup>where
    G::Timestamp: TotalOrder + Lattice + Ord,{
    // Required method
    fn count_total_core<R2: Semigroup + From<i8> + 'static>(
        &self,
    ) -> Collection<G, (K, R), R2>;

    // Provided method
    fn count_total(&self) -> Collection<G, (K, R), isize> { ... }
}

Expand description

Extension trait for the count differential dataflow method.

Required Methods§

source

fn count_total_core<R2: Semigroup + From<i8> + 'static>( &self, ) -> Collection<G, (K, R), R2>

Count for general integer differences.

This method allows count_total to produce collections whose difference type is something other than an isize integer, for example perhaps an i32.

Provided Methods§

source

fn count_total(&self) -> Collection<G, (K, R), isize>

Counts the number of occurrences of each element.

§Examples

use differential_dataflow::input::Input;
use differential_dataflow::operators::CountTotal;

::timely::example(|scope| {
    // report the number of occurrences of each key
    scope.new_collection_from(1 .. 10).1
         .map(|x| x / 3)
         .count_total();
});

Object Safety§

This trait is not object safe.

Implementors§

source §

impl<G, K, T1> CountTotal<G, K, <T1 as TraceReader>::Diff> for Arranged<G, T1>
where G: Scope<Timestamp = T1::Time>, T1: for<'a> TraceReader<Val<'a> = &'a ()> + Clone + 'static, for<'a> T1::Key<'a>: IntoOwned<'a, Owned = K>, for<'a> T1::Diff: Semigroup<T1::DiffGat<'a>> + ExchangeData, K: ExchangeData, T1::Time: TotalOrder,