State is a lazy datatype and as such we can combine many simple transitions into one very complex one. This gives us a lot of control over how our state changes over time. In this lesson we will use this to our advantage and combine many transactions…

When combining multiple State ADT instances that depend on the same input, using chain can become quite burdensome. We end up having to play leapfrog with values inside of nested chain statements. Very reminiscent of the old callback nastiness we had…

We build our first state transactions as two discrete transactions, each working on a specific portion of the state. Each of these transitions are governed by an acceptable range and we want to be able to apply these limit within our model. With our…

Let's say we want to write a most simple implementation 'avg' function: const avg = list => { let sum = 0; for(let i = 0; i < list.length; i++) { sum += list[i] } return sum / list.length } Basiclly, the 'avg' function doing two things: Calculate su…

Recently, I am learning Working with ADT. Got some extra thought about State Monad. Basiclly how to thinking in State. First, we need to know the type of State: State returns Pair with Unit on the left, and state on the right: State(state => Pair(Uni…

An introduction to concatting items via the formal Semi-group interface. Semi-groups are simply a type with a concat method that are associative. We define three semigroup instances and see them in action. 1. What is Semigroups: Array type, String ty…

We take a closer look at the get construction helper and see how we can use it to lift a function that maps the state portion and updates the resultant with the result. Using get in this fashion, we then demonstrate how we can make accessors that can…

ReaderT is a Monad Transformer that wraps a given Monad with a Reader. This allows the interface of a Reader that enables the composition of computations that depend on a shared environment (e -> a), but provides a way to abstract a means the Reader …

The typical Redux Reducer is function that takes in the previous state and an action and uses a switch case to determine how to transition the provided State. We can take advantage of the Action Names being Strings and replace the typical switch case…

By using the State ADT to define how our application state transitions over time, we clear up the need for a some of the boilerplate that we typically need for a solid Redux integration. We can keep our action names and creators in the same file as t…