Trait Aggregate 

pub trait Aggregate {
    // Required methods
    fn update(&mut self, headers: &Headers, row: &Row) -> Result<()>;
    fn value(&self) -> String;
    fn colname(&self) -> &str;
}

Aggregates used while reducing must implement this trait.

Required Methods

fn update(&mut self, headers: &Headers, row: &Row) -> Result<()>

Updates the current value with the next row of data.

fn value(&self) -> String

Gets the current value.

fn colname(&self) -> &str

Gets this aggregate’s colname

Implementors