Trait differential_dataflow::operators::threshold::ThresholdTotal [−] [src]

pub trait ThresholdTotal<G: Scope, K: Data, R: Diff> where
    G::Timestamp: TotalOrder + Lattice + Ord, {
    fn threshold_total<R2: Diff, F: Fn(R) -> R2 + 'static>(
        &self, 
        thresh: F
    ) -> Collection<G, K, R2>;

    fn distinct_total(&self) -> Collection<G, K, isize> { ... }
}

Extension trait for the distinct differential dataflow method.

Required Methods

Reduces the collection to one occurrence of each distinct element.

Examples

extern crate timely;
extern crate differential_dataflow;

use differential_dataflow::input::Input;
use differential_dataflow::operators::ThresholdTotal;

fn main() {
    ::timely::example(|scope| {
        // report the number of occurrences of each key
        scope.new_collection_from(1 .. 10).1
             .map(|x| x / 3)
             .threshold_total(|c| c % 2);
    });
}

Provided Methods

Reduces the collection to one occurrence of each distinct element.

This reduction only tests whether the weight associated with a record is non-zero, and otherwise ignores its specific value. To take more general actions based on the accumulated weight, consider the threshold method.

Examples

extern crate timely;
extern crate differential_dataflow;

use differential_dataflow::input::Input;
use differential_dataflow::operators::ThresholdTotal;

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

Implementors