This post is similar to previous post. The difference is in this post, we are going to see how to handle both successfuly result and error result by using Pair functor. So, still we have our funs.js: which is the same as previous post. const fs = req…

Let's say we are going to read some files, return the first file which pass the prediction method, this prediction method can be just check whether the file content contains more than 50 chars. For reading the file, it has tow requirements, first we…

We refactor a standard node callback style workflow into a composed task-based workflow. Original Code: const app = () => { fs.readFile('config.json', 'utf-8', (err, content) => { if (err) throw err; /g, '); fs.writeFile('config1.json', newContents,…

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 …

Lifting Now, let's review map from another perspective. map :: (T -> R) -> [T] -> [R] accepts 2 parameters, a function f :: T -> R and a list list :: [T]. [T] is a generic type paramterized by T, it's not the same as T, but definitely shares s…

In functional programming, a monad is a design pattern that defines how functions, actions, inputs, and outputs can be used together to build generic types,[1] with the following organization: Define a data type, and how values of that data type are…

JavaScript Functional Programming JavaScript 函数式编程 anonymous function https://en.wikipedia.org/wiki/Anonymous_function Lambda function https://en.wikipedia.org/wiki/Lambda_function http://en.wikipedia.org/wiki/Lambda_calculus Ramda v0.27.0 https://ra…

1. Functional programming treats computation as the evaluation of mathematical and avoids state and mutable data. Scala encourages an expression-oriented programming(EOP) 1) In expression-oriented programming every statement is an expression. A state…

Functions in Java Prior to the introduction of Lambda Expressions feature in version 8, Java had long been known as a purely object-oriented programming language. "Everything is an Object" is the philosophy deep in the language design. Objects a…

background In pursuit of a real-world application, let’s say we need an e-commerce web applicationfor a mail-order coffee bean company. They sell several types of coffee and in differentquantities, both of which affect the price. Imperative methods F…