Struct Writer 

pub struct Writer<A, W> { /* private fields */ }

A Writer monad: a computation that produces a log alongside a value.

Wraps a pair (A, W) where W is a monoid.

Implementations

impl<A, W: Default + Clone> Writer<A, W>

pub fn new(value: A, log: W) -> Self

Create a writer with the given value and log.

pub fn pure(value: A) -> Self

Return a writer that writes nothing.

pub fn get_value(self) -> A

Extract the value.

pub fn get_log(&self) -> &W

Extract the log.

pub fn run(self) -> (A, W)

Run the writer, producing (value, log).