Scala: Applicative with scalaz example

I’ve talked on Functor previously, will repeat myself that construction is very useful in the Scala's world. We covered Comonad as well, it is extending Functor and adds functionality for the extraction value or the wrapping of already wrapped.

This post is related to Applicative. Applicative is coupled with Functor, even has an alternative name: Applicative Functor. At first let look into class hierarchy for Applicative in scalaz library:

Rework: Monads in Scala - 3

Today we will speak more about flatMap, Monadic Zero and other steps.

Let's start from the Business. Should I use Monads?

Its good to start with Scala's Option class, but while we are still don't understand the theory, lets reinvent the wheel to drive into details. Additionally we will try to follow Function and Object Oriented best practices and won't do optimizations etc, while we are not implementing library.

Rework: Monads in Scala - 1

I have to spend more time than other (smart guys) trying to get simple topics. As a profit - getting clean description for myself - using simple (clean for non math geek) vision. I've read hundred of articles/examples/... + done few presentations on the same topic. Just want to finalize it and forget:)

As a conclusion generalization of my previous self-study experience I would kindly ask James Iry:

Usually articles that start with words like "monad" and "functor" quickly devolve into soup of Greek letters. That's because both are abstract concepts in a branch of mathematics called category theory and explaining them completely is a mathematical exercise.

JAMES IRY

But there must be possibility to avoid complexity, to allow understanding the topic while reading in the bus or 3 minutes before falling asleep. U r welcome to the world of Monads in Scala.