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Functional programming is a paradigm which attempts to solve computational problems by the chained evaluation of functions whose output is determined by their inputs rather than the programme state. In this style of programming, side effects and mutable data are deprecated and usually strictly isolated.

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I just learned about currying, and while I think I understand the concept, I'm not seeing any big advantage in using it. As a trivial example I use a function that adds two values (written in ML). ...
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I'm a Sr. front-end dev, coding in Babel ES6. Part of our app makes an API call, and based on the data model we get back from the API call, certain forms need to be filled out. Those forms are ...
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In Java 8's java.util.function package, we have: Function: Takes one argument, produces one result. Consumer: Takes one argument, produces nothing. Supplier: Takes no argument, produces one result. .....
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I've been doing some functional JavaScript. I had thought that Tail-Call Optimization had been implemented, but as it turns out I was wrong. Thus, I've had to teach myself Trampolining. After a bit of ...
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I've seen people talking about Free Monad with Interpreter, particularly in the context of data-access. What is this pattern? When might I want to use it? How does it work, and how would I implement ...
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I've heard a lot of talk about using functional languages such as Haskell as of late. What are some of the big differences, pros and cons of functional programming vs. object-oriented programming?
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OO programming literature is full of design patterns. Most books on object oriented programming dedicate a chapter or two to design patterns like factories and decorators. So what are the equivalent ...
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I feel that side effects are a natural phenomenon. But it is something like taboo in functional languages. What are the reasons? My question is specific to functional programming style. Not all ...
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How does a functional programming language, such as Elm, achieve "No runtime exceptions"? Coming from an OOP background, runtime exceptions have been part of whatever framework that is based ...
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F# and Scala are both functional programming langugages that don't force the developer to only use immutable datatypes. They both have support for objects, can use libraries written in other languages ...
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What I mean about that is that in nearly every tutorial I've read about functional languages, is that one of the great things about functions, is that if you call a function with the same parameters ...
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In functional programming since almost all data structure are immutable, when the state has to change a new structure is created. Does this mean a lot more memory usage? I know the object oriented ...
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I watched Stuart Sierra's talk "Thinking In Data" and took one of the ideas from it as a design principle in this game I'm making. The difference is he's working in Clojure and I'm working in ...
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I'm diving into the world of functional programming and I keep reading everywhere that functional languages are better for multithreading/multicore programs. I understand how functional languages do a ...
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During my four years at university we have been using much functional programming in several functional programming languages. But I have also used much object oriented programming to, and in fact I ...
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I am learning functionnal programming with Haskell, and I try to grab concepts by first understanding why do I need them. I would like to know the goal of arrows in functional programming languages. ...
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After reading many posts explaining closures here I'm still missing a key concept: Why write a closure? What specific task would a programmer be performing that might be best served by a closure? ...
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What are combinators? I'm looking for: a practical explanation examples of how they are used examples of how combinators improve the quality/generality of code I'm not looking for: explanations of ...
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I'm a little bit confused about 'function' and 'lambda'. I've seen some examples showing that the scheme keyword lambda works very similarly to the JavaScript keyword function, but I really don't ...
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What language, in your opinion, allows the average programmer to output features with the least amount of hard-to-find bugs? This is of course, a very broad question, and I'm interested in very broad ...
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I've been messing around with functional programming languages for a few years, and I keep encountering this phrase. For example, it is a chapter of "The Little Schemer, which certainly predates ...
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Most of DDD tactical design patterns belong to object-oriented paradigm, and anemic model describes the situation when all business logic is put into services rather than objects thus making them a ...
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I have heard a lot of times when other developers use that phrase to "advertise" some patterns or developing best practices. Most of the time this phrase is used when you are talking about benefits of ...
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I have read a lot of threads about functional programming languages lately (almost in the past year, in fact). I would really like to pick one and learn it thoroughly. Last [course] semester, I have ...
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So far I heard about : Lambda calculus Lambda programming Lambda expressions Lambda functions Which all seems to be related to functional programming... Apparently it will be integrated into C++1x, ...
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In a blog post on F# for fun and profit, it says: In a functional design, it is very important to separate behavior from data. The data types are simple and "dumb". And then separately, you have ...
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I have been reading The Early History of Smalltalk and there are a few mentions of "assignment" which make me question my understanding of its meaning: Though OOP came from many motivations, two ...
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I have some experience in object oriented programming languages like c# or ruby. I know how to design a program in object oriented style, how to create classes and objects, and how to define relations ...
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I appreciate a lot the new Java 8 features about lambdas and default methods interfaces. Yet, I still get bored with checked exceptions. For instance, if I just want to list all the visible fields of ...
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I've been hearing a lot of enthusiasm about functional programming languages lately, with regards to Scala, Clojure, and F#. I've recently started studying Haskell, to learn the FP paradigm. I love ...
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OK, so the title is a little clickbaity but seriously I've been on a tell, don't ask (TDA) kick for a while. I like how it encourages methods to be used as messages in true object-oriented fashion. ...
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I've been reading over and over that functional languages are ideal (or at least very often useful) for parallelism. Why is this? What core concepts and paradigms are typically employed and which ...
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I currently code with C, C++, and Python. I'm wanting to pick up a functional programming language, and right now I'm leaning toward Haskell. I do NOT want to start a "Haskell vs Lisp" war here; what ...
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Say we have a normal pure function such as function add(a, b) { return a + b } And then we alter it such that it has a side effect function add(a, b) { writeToDatabase(Math.random()) return a +...
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The IO monad in Haskell is often explained as a state monad where the state is the world. So a value of type IO a monad is viewed as something like worldState -> (a, worldState). Some time ago I ...
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I've found the SOLID principles quite useful when thinking about object-oriented design. Is there a similar / equivalent set of language-agnostic principles tailored for functional programming?
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Today I've just seen this article which described the relevance of SOLID principle in F# development- F# and Design principles – SOLID And while addressing the last one - "Dependency inversion ...
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Are closures considered impure in functional programming? It seems one can generally avoid closures by passing values directly to a function. Therefore should closures be avoided where possible? If ...
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I have noticed lately that functional programming languages are gaining popularity. I recently saw how the Tiobe Index shows an increase in their popularity in comparison to the last year although ...
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TL;DR : Do functional languages handle recursion better than non-functional ones? I am currently reading Code Complete 2. At some point in the book, the author warns us about recursion. He says it ...
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Most functional languages use linked lists as their primary immutable data structure. Why lists, and not e.g. trees? Trees can also reuse paths, and even model lists.
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What are some techniques I might use to consistently refactor code removing the reliance on existential types? Typically these are used to disqualify undesired constructions of your type as well as to ...
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Case: I'm working at a company, writing an application in Python that is handling a lot of data in arrays. I'm the only developer of this program at the moment, but it will probably be used/modified/...
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I was browsing through the Amazon.com Bookstore and I came across the book "Functional Programming for Java Developers". I know some very basic Functional Programming and have been programming in ...
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Possible Duplicate: Functional Programming vs. OOP How to write manageable code with functional programming? In OOP, your basic unit of organization for code is the class. A frequently used ...
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I often encounter the following statements / arguments: Pure functional programming languages do not allow side effects (and are therefore of little use in practice because any useful program does ...
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I wonder what are the advantages of Maybe monad over exceptions? It looks like Maybe is just explicit (and rather space-consuming) way of try..catch syntax. update Please note that I'm intentionally ...
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What is the deal with functional programming? I see talk about it a lot but to be honest I've never found them at all useful. Why do so many universities apparently teach them?
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I have seen that in imperative paradigms f(x)+f(x) might not be the same as: 2*f(x) But in a functional paradigm it should be the same. I have tried to implement both cases in Python and Scheme, ...
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Part 1 Clearly Immutability minimizes the need for locks in multi-processor programming, but does it eliminate that need, or are there instances where immutability alone is not enough? It seems to me ...
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