Enum Reducer 

pub enum Reducer {
    Count,
    Max,
    Mean,
    Median,
    Min,
    Std,
    Sum,
}

The closed reducer vocabulary of the first reduce stage.

Reducers that can observe an empty stream (max, min, mean, median, std) are admitted only under group bindings, where every group is witnessed by at least one row; count and sum stay total on empty streams.

Variants

Count

Count surviving rows.

Max

The largest input value.

Mean

The arithmetic mean of input values.

Median

The statistical median of input values.

Min

The smallest input value.

Std

The sample standard deviation of input values.

Sum

The total of input values.

Implementations

impl Reducer

pub const fn total_without_groups(self) -> bool

Whether this reducer yields a defined result on an empty stream.

pub const fn requires_input(self) -> bool

Whether this reducer consumes an input binding.

Trait Implementations

impl Clone for Reducer

fn clone(&self) -> Reducer

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Copy for Reducer

impl Debug for Reducer

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Eq for Reducer

impl PartialEq for Reducer

fn eq(&self, other: &Reducer) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl Serialize for Reducer

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for Reducer