Namespace Writer

This package provides methods for a computation which allows writing into external records.

A Writer<W, A> object represents a computation, returning A and writing W out:

type Writer<W, A> = () => [returned: A, written: W];
// Note that the actual code is defined as a special case of `WriterT`.
Copy

And you can work with it by the following methods:

• censor - Censors and transforms data to be written.
• listen - Listens the written record.
• pass - Applies the function returned from a Writer to a record.
• tell - Writes data as a record.
• evaluateWriter - Runs a Writer and gets only the result.
• executeWriter - Runs a Writer and gets only the written record.
• mapWriter - Transforms output and record of a Writer.

Moreover a WriterT<R, M, A> monad transformer is the generalized version of Writer<R, A>. It returns not A, but object on monad M.