Function listens

listens<W, B>(
mapper: (w: W) => B,
): <A>(writer: Writer.Writer<W, A>) => Writer.Writer<W, [A, B]>
Creates an action that executes writer, maps its output and adds to the value of the computation.
Type Parameters
- W
- B
Parameters
- mapper: (w: W) => B
  The function to map the output of the computation.
Returns <A>(writer: Writer.Writer<W, A>) => Writer.Writer<W, [A, B]>
The computation that adds its output to the value.
- Defined in src/writer.ts:204