Trait differential_dataflow::operators::group::GroupUnsigned [−] [src]

pub trait GroupUnsigned<G: Scope, U: Unsigned + Data + Default, V: Data> where G::Timestamp: LeastUpperBound {
    fn group_u<L, V2: Data>(&self, logic: L) -> Collection<G, (U, V2)> where L: Fn(&U, &mut CollectionIterator<DifferenceIterator<V>>, &mut Vec<(V2, i32)>) + 'static;
}

Extension trait for the group_u differential dataflow method.

Required Methods

fn group_u<L, V2: Data>(&self, logic: L) -> Collection<G, (U, V2)> where L: Fn(&U, &mut CollectionIterator<DifferenceIterator<V>>, &mut Vec<(V2, i32)>) + 'static

Groups records by their first field, when this field implements Unsigned.

This method uses a Vec<Option<_>> as its internal storage, allocating enough memory to directly index based on the first fields. This can be very useful when these fields are small integers, but it can be expensive if they are large and sparse.

Implementors