Trait PrefixSum 

pub trait PrefixSum<'scope, T: Timestamp, K, D> {
    // Required methods
    fn prefix_sum<F>(self, zero: D, combine: F) -> Self
       where F: Fn(&K, &D, &D) -> D + 'static;
    fn prefix_sum_at<F>(
        self,
        locations: VecCollection<'scope, T, (usize, K)>,
        zero: D,
        combine: F,
    ) -> Self
       where F: Fn(&K, &D, &D) -> D + 'static;
}

Extension trait for the prefix_sum method.

Required Methods

fn prefix_sum<F>(self, zero: D, combine: F) -> Self

where F: Fn(&K, &D, &D) -> D + 'static,

Computes the prefix sum for each element in the collection.

The prefix sum is data-parallel, in the sense that the sums are computed independently for each key of type K. For a single prefix sum this type can be (), but this permits the more general accumulation of multiple independent sequences.

fn prefix_sum_at<F>( self, locations: VecCollection<'scope, T, (usize, K)>, zero: D, combine: F, ) -> Self

where F: Fn(&K, &D, &D) -> D + 'static,

Determine the prefix sum at each element of location.

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors

impl<'scope, T, K, D> PrefixSum<'scope, T, K, D> for VecCollection<'scope, T, ((usize, K), D)>

where T: Timestamp + Lattice, K: ExchangeData + Hash, D: ExchangeData + Hash,