A functional programming language

learn more… | top users | synonyms

1
vote
1answer
176 views

Building proprietary software over haskell compiler [closed]

Is it perfectly legal to use GHC as base and build some commercial application over its top ? Are there such examples I can can interact with ?
7
votes
6answers
777 views

Challenges for the experienced coder to learn functional programming? [closed]

What are the challenges that an experienced programmer with the usual C++/UNIX background would face when trying to learn functional programming? The main motive for learning is to gain a fresh ...
6
votes
2answers
700 views

Can someone explain the concept behind Haskell's memoization?

(note I'm putting the question here because it's about the conceptual mechanics of it, rather than a coding problem) I was working on a small program, that was using a sequence of fibonacci numbers ...
11
votes
2answers
492 views

Are types erased in Haskell?

Haskell has a notion of “generic functions” that has some apparent similarity with common lisp—having neither experience with Haskell nor with common lisp, I might be very approximative here. This ...
15
votes
2answers
432 views

Side effect-free interface on top of a stateful library

In an interview with John Hughes where he talks about Erlang and Haskell, he has the following to say about using stateful libraries in Erlang: If I want to use a stateful library, I usually build ...
1
vote
1answer
272 views

Haskell: Best tools to validate textual input?

In Haskell, there are a few different options to "parsing text". I know of Alex & Happy, Parsec and Attoparsec. Probably some others. I'd like to put together a library where the user can input ...
18
votes
2answers
2k views

Type checking and recursive types (Writing the Y combinator in Haskell/Ocaml)

When explaining the Y combinator in the context of Haskell, it's usually noted that the straight-forward implementation won't type-check in Haskell because of its recursive type. For example, from ...
11
votes
2answers
952 views

Functional programming and stateful algorithms

I'm learning functional programming with Haskell. In the meantime I'm studying Automata theory and as the two seem to fit well together I'm writing a small library to play with automata. Here's the ...
21
votes
3answers
2k views

Is return-type-(only)-polymorphism in Haskell a good thing?

One thing that I've never quite come to terms with in Haskell is how you can have polymorphic constants and functions whose return type cannot be determined by their input type, like class Foo a ...
7
votes
1answer
794 views

Maths needed to understand theory behind Haskell's type system?

Recently, I've become deeply interested in Haskell. While attempting to learn new concepts (e.g. the forall keyword and ST monad) and Haskell's type system in general, I continually run into ...
32
votes
4answers
9k views

Are there any downsides or problems with Haskell?

I'm looking at diving into Haskell for my next (relatively trivial) personal project. The reasons that I'm tackling Haskell are: Get my head into a purely functional language Speed. While I'm sure ...
18
votes
3answers
9k views

What are the advantages of using LISP and Haskell? Will they make me a better programmer? [closed]

I know Lisp and Haskell are functional and logic programming languages respectively, but what exactly does this mean? How do they differ from other languages? I've heard that learning these will make ...
1
vote
2answers
856 views

Why don't we have a non-turing complete general purpose language yet? [duplicate]

Non-turing complete languages can solve every practical problem that a turing-complete language can. Also, they are much more analyzable than turing complete languages. The compiler can comprehend the ...
8
votes
1answer
1k views

Why is the Scala Option type not called Maybe, just as in Haskell?

Why is the Scala Option type not called Maybe, just as in Haskell? Maybe makes a lot more "semantic sense" to me, but maybe Option has different behaviour I am not aware of. Is there any particular ...
11
votes
2answers
2k views

Haskell memory efficiency - which is the better approach?

We are implementing a matrix compression library based on a modified two dimensional grammar syntax. Now we have two approaches for our data types -which one will be better in case of memory usage? ...
0
votes
1answer
211 views

Why does this article state that graduate education liberate one from concerns like the efficiency of hardware-based integers? [closed]

Quoting The Evolution of Haskell Programmer, graduate education tends to liberate one from petty concerns about, e.g., the efficiency of hardware-based integers What exactly does this ...
5
votes
2answers
1k views

What is this algorithm for converting strings into numbers called?

I've been doing some work in Parsec recently, and for my toy language I wanted multi-based fractional numbers to be expressible. After digging around in Parsec's source a bit, I found their ...
8
votes
2answers
408 views

Choosing the language to build an app in based on hiring market vs performance and maintainability [closed]

I'm facing a choice of whether to start building Haskell components for a certain production app that is all done in Ruby. I'm leaning toward Haskell for several reasons, primarily speed (compiled ...
8
votes
3answers
612 views

When is it a good time to reason about performance in Haskell?

Simon Peyton Jones himself recognizes that reasoning about performance in Haskell is hard due to the non strict semantics. I have yet to write a significant project in haskell so I wonder: can I ...
7
votes
2answers
444 views

Is Haskell function composition an instance of pipe & filter architectural pattern

The pipe & filter architectural pattern is defined as a chain of processing elements, arranged so that the output of each element is the input of the next. Every example seems to consider ...
2
votes
5answers
636 views

The rationale behind Falsy values [closed]

I'm wondering what the arguments for/against Falsy values are. On what principles would you decide to add or exclude them from a language? Are there any problems you could see them causing off-hand? ...
12
votes
2answers
911 views

Functional reactive programming — is Fay expressive enough?

So I'm doing a fairly involved javascript/html client with lots of ajax calls and other involvements of callback-ism. I'm entertaining the thought of using Fay for this purpose. I'm aware of Elm. ...
70
votes
13answers
36k views

Is Haskell worth learning? [closed]

I am looking at this question primarily from a career point of view, so I hope you answer it accordingly. I am fairly proficient with Python, can write C++ and I am a final year student of computer ...
8
votes
2answers
1k views

Could we build a functional computer?

As mush as FP has done, in the end, all our programs are structured. That is, it doesn't matter how pure or functional we make a them - they are always translated to assembly, so what actually runs ...
1
vote
1answer
725 views

Modern REPL for Haskell - is anybody working on it? [closed]

It's time Haskell had a modern REPL like Mathematica's (or better). Make each calculation run in a separate thread, so user has control over each computation box's resources (ability to pause, play, ...
-1
votes
1answer
122 views

Exclude the zero in the given data in Haskell [closed]

I have a list of integers. Also, I have a function which returns True when the element is non-zero, and returns False when the element is zero (let's call it FUNCTION1). So, how to define another ...
8
votes
1answer
436 views

Necessity to learn haskell language extension for production

Haskell core language is really simple. Coming from an OO background, the main difficulty is to adapt to the pure functional paradigm. While learning "basic" Haskell, I have always considered ...
6
votes
2answers
1k views

Is Haskell/Clojure actually unsuited for dynamic systems such as particle simulation?

I've been told in previous questions that functional programming languages are unsuited for dynamic systems such as a physics engine, mainly because it's costly to mutate objects. How realistic is ...
9
votes
9answers
1k views

Resources for improving your comprehension of recursion? [closed]

I know what recursion is (when a patten reoccurs within itself, typically a function that calls itself on one of its lines, after a breakout conditional... right?), and I can understand recursive ...
17
votes
1answer
807 views

What's the progress on Haskell records?

Recently I stumbled once again on the issues of Haskells records, in particular the uniqueness of field names (it's a pain ...) I already read A proposal for records in Haskell from SPJ and Greg ...
7
votes
2answers
310 views

Why have a wrapper constructor when storing a function in a data type?

I can never do too many Haskell tutorials. There is always something to refine and learn. So, I am working through chapter 10 of Real World Haskell, and everything makes sense. but Why do newtype ...
8
votes
2answers
1k views

Inspirational software for end-users written in Haskell? [closed]

I think great technology is invisible. Besides the usual suspects (GHC, Xmonad, proprietary trading software) what great examples are there of end-user software written in Haskell? I think good ...
2
votes
1answer
298 views

Erlang/Haskell web service to server files [closed]

I have across a thread mentioning that Erlang would not be suited for a web application serving files. I was curious whether anyone had any experience building such webservice with erlang? Would ...
2
votes
1answer
252 views

Good serialization solution for communication between Python AND Haskell programs? [closed]

I found this: http://msgpack.org/ But.. I've never used it, so I don't know what whether it is much good. Anybody has proposals? Basic requirements: serialize as many data structures used ...
7
votes
2answers
303 views

Who first coined the term Higher Order Function and/or First Class Citizen?

I've come to understand that long before Haskell, O'Caml or LISP, higher order functions were an academic research subject and in mathematics, Schönfinkel (in 1967) and Haskell Curry (in 1968) already ...
7
votes
2answers
457 views

What's a good math textbook to have on my desk while studying Haskell? [closed]

I just started learning Haskell and it seems like you can't get too far in the language without being comfortable ( or at least exposed ) to certain branches of mathematics. Unfortunately I have major ...
10
votes
6answers
5k views

Which self balancing binary tree would you recommend?

I'm learning Haskell and as an exercise I'm making binary trees. Having made a regular binary tree, I want to adapt it to be self balancing. So: Which is most efficient? Which is easiest to ...
15
votes
1answer
972 views

Why doesn't Haskell have type-level lambda abstractions?

Are there some theoretical reasons for that (like that the type checking or type inference would become undecidable), or practical reasons (too difficult to implement properly)? Currently, we can ...
19
votes
2answers
2k views

What's the difference in content between Chris Okasaki's 1996 thesis and 1999 book, Purely Functional Data Structures?

I want to read Purely Functional Data Structures. I've easily found the thesis (which is freely available as a PDF), but see that there's a book available also. So I'd like to know what the ...
19
votes
2answers
1k views

How to improve efficiency with functional programming?

I've recently been going through the Learn You a Haskell for Great Good guide and as practice I wanted to solve Project Euler Problem 5 with it, which specifies: What is the smallest positive ...
8
votes
1answer
470 views

Better to use error monad with validation in your monadic functions, or implement your own monad with validation directly in your bind?

I'm wondering what's better design wise for usability/maintainability, and what's better as far as fitting with the community. Given the data model: type Name = String data Amount = Out | Some | ...
27
votes
2answers
2k views

Applying Denotational Semantics to design of Programs

I've read a bit on denotational semantics (DS) and I'm very intrigued about the process of designing computer programs where types and functions have strong and clear mappings to mathematics. Are ...
8
votes
3answers
611 views

Devising test of Haskell's value/reference semantics

In imperative languages, it is trivial to devise a programming test of language's use of "value semantics" or "reference semantics". One could do the following and check the value of a (where Vertex ...
7
votes
1answer
419 views

What monad is the opposite of the error monad in haskell

In the error monad, the first failure halts any execution further just carrying the fault through any following binds. What monad halts on success only carrying forward successes, and basically ...
2
votes
1answer
2k views

Fastest Haskell library sort implementation

I am implementing an application in Haskell and, for sorting, I use the library function Data.List.sort. However, I was wondering whether this is the fastest sort implementation in the Haskell ...
4
votes
1answer
536 views

Why would I use Control.Exception in Haskell?

I'm trying to really master Haskell error handling, and I've gotten to the point where I don't understand why I would use Control.Exception instead of Control.Monad.Error. The way I can see it, I can ...
24
votes
3answers
2k views

Why do some functional languages need software transactional memory?

Functional languages, by definition, should not maintain state variables. Why, then, do Haskell, Clojure, and others provide software transactional memory (STM) implementations? Is there a conflict ...
9
votes
3answers
6k views

Fastest Functional Language

I've recently been delving into functional programming especially Haskell and F#, the prior more so. After some googling around I could not find a benchmark comparison of the more prominent functional ...
3
votes
2answers
352 views

What's the benefit of the Nothing constructor in Haskell?

I'm new to Haskell and I'm not really sold on the Nothing constructor. It sounds like just another silent fail that's going to create headaches down the line. It seems much more useful to throw an ...
3
votes
2answers
875 views

Lazy Processing of Streams

I have the following problem scenario: I have a text file and I have to read it and split it into lines. Some lines might need to be dropped (according to criteria that are not fixed). The lines ...