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 ...

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2
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1answer
59 views

FP and board game state

I wanted to implement the game of Tic Tac Toe using a functional language (in my case, Scala) but I'm unsure how to go about managing the board game state after each player makes their move. I ...
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2answers
123 views

Is functional language without runtime written in C possible?

Every functional language that compiles to native code relies on quite big runtime written in C programming language (well at least ones that I know of, for example Haskell, OCaml, Gambit/Chicken ...
1
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1answer
77 views

Functional Programming style: How to write functions - explicit currying, implicit currying or lamdas?

So I have been using F# for a while and studying a bit of Haskell on the side and I have realized I could rewrite the exact same function one of three different ways. Either with implicit currying, ...
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0answers
21 views

Permutations of a limited number set

Im trying to find all permutations of a 6 number set given the following limitations. The set contain 6 numbers The sum of the set equals 111 A number is in the range 1 to 36 inclusive I need to ...
-3
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0answers
58 views

Bewildered: programming for the real world [on hold]

I'm currently working as a iOS developer. Before that I worked as a full stack web developer (JS, Ruby) while also maintaining the servers (linux). When I started out years ago I did a little game ...
11
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4answers
403 views

Dealing with state problems in functional programming

I've learned how to program primarily from an OOP standpoint (like most of us, I'm sure), but I've spent a lot of time trying to learn how to solve problems the functional way. I have a good grasp on ...
-3
votes
0answers
68 views

Migrate from .net to linux programming [closed]

Ok, so when you start a desktop .net application with some database needs, you generally go this way: Open Visual Studio and create a windows forms/wpf application Decides which database you will ...
-1
votes
1answer
55 views

Significance of '__name__ ' attribute in python

1) Below python code, >>> def f(): return creates a function type object which has __name__ attribute with value 'f' which looks fine. But, 2) Below line of code, >>> x = ...
5
votes
1answer
235 views

How to represent hard-to-calculate “properties” of “objects” in functional code?

I have a polyline "class" in my Clojure program, which is represented by a vector of points. (It's not really a class or anything.) The polyline's length (in the geometric sense) is something that is ...
-2
votes
0answers
54 views

What are the Pros and Cons of recursion over loops? [duplicate]

What can be said for the benefits and negatives of recursive functions over using a loop? For example. Is it just a matter of writing less code? Surely recursion has the potential to StackOverflow ...
5
votes
3answers
760 views

Can “higher order function” feature allow/maintain abstraction and encapsulation?

Below is the function repeat written using a functional paradigm, such that when called as repeat(square, 2)(5) it will apply the square function 2 times on the number 5, something like ...
0
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0answers
41 views

How and where to make global function file in jsp sevlet web application

I am making a website in Servlet&JSP. I am looking for good way to make a specific function file from where I can call and declare my common functions. If I made a java file function. Java, so is ...
2
votes
1answer
297 views

Local Updates in Persistent/Immutable Data Structures

I'm getting into ReactJS and am intrigued but also confused about persistent data structures. I love the idea, but I'm not sure how to take my MV*, Mutable, Observable Bindings experience in designing ...
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votes
4answers
115 views

Does this python program obey functional paradigm?

Below is the hailstone sequence program considering the rule of thumb in functional programming. The simple rule of thumb is: if you can replace any expression, sub-expression or subroutine call ...
22
votes
3answers
2k views

What is referential transparency?

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, ...
4
votes
1answer
101 views

How would I isolate changes to mutable state if I need to run two queries to get the final result?

I'm working on some code that takes search criteria from a Rest API and uses it to query a remote API to return results. As an exercise, I wanted to try to separate all state changes to one place, as ...
1
vote
1answer
105 views

How do I enforce 'referential transparency' in this program?

Below is the python program written to follow the rule of thumb in functional programming. The simple rule of thumb is: if you can replace any expression, sub-expression or subroutine call with ...
5
votes
3answers
4k views

Is the Entity Component System architecture object oriented by definition?

Is the Entity Component System architecture object oriented, by definition? It seems more procedural or functional to me. My opinion is that it doesn't prevent you from implementing it in an OO ...
11
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1answer
343 views

Using uniqueness types to implement safe parallelism

I've been interested in uniqueness types as an alternative to monads in pure functional languages for some time; unfortunately, this is kind of an esoteric area of CS research and online resources ...
3
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2answers
545 views

How is intermediate data organized in MapReduce?

From what I understand, each mapper outputs an intermediate file. The intermediate data (data contained in each intermediate file) is then sorted by key. Then, a reducer is assigned a key by the ...
0
votes
1answer
100 views

Abstracted better? Data driven string creation

I am trying to post this question neutral of programming language so it helps the widest audience. But for those who must know, I am using Objective-C and iOS frameworks. The background: I have a ...
16
votes
6answers
988 views

Does functional programming increase the 'representational gap' between problems and solutions? [closed]

Since machine language (e.g., 0110101000110101) computer languages have generally evolved to higher forms of abstraction, generally making it easier to understand the code when it's applied to a ...
0
votes
1answer
49 views

Dealing with error in data - Idempotent approach

A prior question had an answer that interested me from a design perspective. I work in geospatial data and occasionally have to deal with voids when I read these binary files into my product. What is ...
0
votes
1answer
50 views

Choose approaches for updating an object

Say I have a simple object created by from user input: var input = { url: 'http://example.com/', path: 'abc', user: 'adam' }; And I am to write function(s) that update url and path properties ...
2
votes
1answer
78 views

How to make an interpreter for a stack of Free Monad Transformers

I like the idea of using Free monads to "purify" code and I've used it in some simple scenarios. However, I can't seem to figure out how to write an interpreter for a Free monad transformer. In ...
2
votes
1answer
98 views

Expected time for lazy evaluation with nested functions?

A colleague and I are doing a free R course, although I believe this is a more general lazy evaluation issue, and have found a scenario that we have discussed briefly and I'd like to find out the ...
6
votes
1answer
149 views

Is the use of DSLs in a state monad a good approach to building complex stateful computations?

First, sorry if that title makes no sense. I am a little out of my depth here with the terminology. So, imagine that I'm writing a text editor in Haskell. For the purposes of this question, let's ...
8
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1answer
1k views

Is Rebol a functional programming language?

I ran into Rebol and I was wondering about it. I ran into the following script from here: use [feed questions answers][ feed: load-xml/dom http://stackoverflow.com/feeds/tag/rebol ...
11
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5answers
2k views

How to code in a more functional style in Java?

I code Java for at least 5 years now and I really appreciate how the language works. When looking at new JVM languages (e.g. Scala, Clojure) there is a trend to more functional ways to code and this ...
22
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5answers
2k views

How do purely functional languages handle modularity?

I come from an object oriented background where I've learned that classes are or at least can be used to make a layer of abstraction that allows for easy recycling of code which can then either be ...
0
votes
1answer
146 views

What kind of reputation does Java 8 have among “enterprise” companies? [closed]

Are the new, functionally-inspired features of Java 8 well-regarded within the enterprise development community? Have they been adopted by large companies? Have coding standards been updated to ...
14
votes
9answers
2k views

What would be good factual arguments to convince high level management to consider functional programming? [closed]

There are tons of "theoretical" arguments for why functional programming is a Good idea (too many for that to have stayed as an open question, and correctly so). However, most of them are arguments ...
36
votes
6answers
10k views

Where are all the functional programming design patterns?

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 ...
2
votes
3answers
189 views

Declaring lambdas in Java8

What would be the best practice to declare lambdas in Java8 code? How it was designed to be used? For example, let's say that we have a method that accept a Function. I want to provide function ...
18
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1answer
1k views

Confusion between F# and C# [duplicate]

I am fairly new to functional programming and C#/F#. What is unclear to me is: Can you do functional programming in C# and/or in F#? Or is it something like, you write some OO code in C#, and some FP ...
2
votes
2answers
320 views

Should we refactor our existing codebase to use functional programming, especially streams? [closed]

We have a large project written in PHP. It almost exclusively uses imperative operations, as in example 1. Should we refactor our existing code to use functional operations? Do you think that the code ...
21
votes
4answers
3k views

Workaround for Java checked exceptions

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 ...
3
votes
1answer
169 views

Functional programming for loop side effect

I am trying to get my head around as to why having a local variable or a for loop inside a function is not considered to be pure functional programming. Given this function: int as_int(char *str) { ...
1
vote
4answers
347 views

Is it possible to use functional paradigm in imperative languages?

If I understand the concept correctly the goal, which functional languages are trying to achieve is to eliminate any side effects from functions and to eliminate a state. The rationale behind this is ...
-1
votes
1answer
79 views

New DDD, context-oriented, functional… approach in building business layer [closed]

We are building some business modules that must be intuitive for developers to use, so the code itself explains and forces developers to use it in certain way. This applies both for enhancing the ...
18
votes
9answers
3k views

Why is the concept of lazy evaluation useful?

It seems lazy evaluation of expressions can cause a programmer to lose control over the order in which their code is executed. I am having trouble understanding why this would be acceptable or desired ...
13
votes
1answer
390 views

What is Banana split and fusion in functional programming?

These terms got mentioned in my university course. Quick googling pointed me to some university papers, but I am looking for a simple explanation.
16
votes
5answers
2k views

Asynchronous Programming in Functional Languages

I'm mostly a C/C++ programmer, which means that the majority of my experience is with procedural and object-oriented paradigms. However, as many C++ programmers are aware, C++ has shifted in emphasis ...
1
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3answers
150 views

What do I use for a variant in a UML class diagram?

Does standard UML specify how a variant (aka tagged union, discriminated union, sum type, etc) should be depicted in a class diagram?
10
votes
5answers
569 views

Why do functional programs have a correlation between compilation success and correctness?

I've been trending toward functional programming for 4 years now, ever since I first started working with LINQ. Recently, I wrote some pure functional C# code and I noticed, first hand, what I've ...
2
votes
1answer
203 views

In what way are union types better for correctness than a common interface?

I've just recently started familiarising myself with functional programming, mostly via F#, and there's one particular functional idiom that I'm not fully understanding the benefits of. I've seen it ...
5
votes
1answer
3k views

Why is imperative programming preferred over functional programming? [closed]

Background: I am proponent of functional programming who works at a VB.NET shop where the prevailing mental model is imperative programming. Being that foundation of our system is WinForms I can ...
0
votes
1answer
149 views

Programming CPU Emulator Functional Style [closed]

I want to write an 8086 CPU emulator in javascript, functional style. How would one conceptualise / design an 8086 emulator, or any CPU emulator that has registers and realmode memory access in a ...
2
votes
1answer
225 views

Is the application architecture of Facebook Flux a new idea?

Facebook announced that it's using the architecture they call Flux to develop their projects. It consists of a single direction dataflow, and concepts like a Dispatcher, Stores and Actions (well ...
0
votes
3answers
202 views

Reference counting & GC in LISP [closed]

What is the main method for reclaiming the memory in LISP? Does LISP really need garbage collection? Would not reference counts suffice? I just wanted to know whether reference counts are enough ...