Struct Transformer

pub struct Transformer {
    pub name: String,
    pub from_col: String,
}

A struct for building a Transform, which you can use with Pipeline::transform_into.

Fields

name: String

from_col: String

Implementations

impl Transformer

pub fn new(col_name: &str) -> Self

pub fn from_col(self, col_name: &str) -> Self

Specify which column the transform should be based on

pub fn keep_unique(self) -> Box<dyn Transform>

Keep the unique values from this column

pub fn sum<'a, N>(self, init: N) -> Box<dyn Transform + 'a>

where N: Display + AddAssign + FromStr + Clone + 'a,

Sum the values in this column.

pub fn reduce<'a, R, V>(self, reduce: R, init: V) -> Box<dyn Transform + 'a>

where R: FnMut(V, &str) -> Result<V, Error> + 'a, V: Display + Clone + 'a,

Reduce the values from this column into a single value using a closure.

pub fn count(self) -> Box<dyn Transform>

Count the rows that were reduced into this row.