Trait RangedUniqueKernel

Source

pub trait RangedUniqueKernel {
    type Array: Array;

    // Required methods
    fn has_seen_all(&self) -> bool;
    fn append(&mut self, array: &Self::Array);
    fn finalize_unique(self) -> Self::Array;
    fn finalize_n_unique(self) -> usize;
    fn finalize_n_unique_non_null(self) -> usize;
}

Expand description

Optimized kernel to calculate the unique elements of an array.

This kernel is a specialized for where all values are known to be in some small range of values. In this case, you can usually get by with a bitset and bit-arithmetic instead of using vectors and hashsets. Consequently, this kernel is usually called when further information is known about the underlying array.

This trait is not implemented directly on the Array as with many other kernels. Rather, it is implemented on a State struct to which Arrays can be appended. This allows for sharing of State between many chunks and allows for different implementations for the same array (e.g. a maintain order and no maintain-order variant).