I've recently been dabbling in functional programming with languages like Lua, Scheme and most notably F# and there are a lot of resources to learn these languages. However, the resources that I've found and have been using essentially teach only the syntax of these languages. While that's important, I can do this in a day or two. I j...
I recently started Erlang, and I notice I constantly get "Warning: variable X is unused" while compiling. For example, take the following function, which finds the maximum element in a list: max([Head|Tail]) -> max(Head,Tail). max(Element,[Head | Tail]) when Element < Head -> max(Head,Tail); max(Element,[Head...
I was browsing the SGI STL documentation and ran into project1st<Arg1, Arg2>. I understand its definition, but I am having a hard time imagining a practical usage. Have you ever used project1st or can you imagine a scenario? ...
so that you can make your program concurrent easily in the future. ...
I'm looking for an algorithm to generate permutations of a set in such a way that I could make a lazy list of them in Clojure. i.e. I'd like to iterate over a list of permutations where each permutation is not calculated until I request it, and all of the permutations don't have to be stored in memory at once. Alternatively I'm looking...
I need help getting my head around the difference between my current OOP notion of state, and the way it would be done in a functional language like Haskell or Clojure. To use a hackneyed example, let's say we're dealing with simplified bank account objects/structs/whatever. In an OOP language, I'd have some class holding a reference ...
I want to learn a functional language that will be good for building web applications in the future. I am choosing between Clojure and Haskell. Which one is a better choice for my purpose? ...
In reading Haskell-related stuff I sometimes come across the expression “tying the knot”, I think I understand what it does, but not how. So, are there any good, basic, and simple to understand explanations of this concept? ...
I recently asked a question about functional programming, and received (good!) answers that prompted more questions (as seems to be the case with learning, sometimes). Here are a couple examples: One answer made reference to an advantage of immutable data structures: each thread can have its own copy. Now, to me, this sounds rather lik...
With the recent news about F# being included with Visual Studio 2010, I got to thinking ... how soon before I see functional programming take hold in the usual "line of business app" space? ...
I need help. what is difference between a parameter passed by reference, and a parameter passed by value? Could you give me some examples please? ...
What are some good links for diving into Erlang and functional programming in general? ...
What are some good links for diving into Haskell and functional programming in general? ...
The question is simple: I cannot understand the Zipper data structure. My question is related to its uses with a Tree. I want to understand how can I change the tree node using zipper. And how not to copy the whole tree (or the most part of it). Please, clarify if I'm wrong with zipper. Maybe it cannot help with the tree update? Or, m...
I just finished reading a book on scala. What strikes me is that every single example in the whole book was numerical in some form or another. Like a lot of programmers, the only math I use is from discrete and combinatorial mathematics, and usually that's not math I program in an explicit way. I'm really missing some compelling example...
Firstly, Real World Haskell, which I am reading, says to never use foldl instead of foldl'. So I trust it. But I'm hazy on when to use foldr vs. foldl'. Though I can see the structure of how they work differently laid out in front of me, I'm too stupid to understand when "which is better." I guess it seems to me like it shouldn't real...
Is there any way to modify the bound value of one of the variables inside a closure? Look at the example to understand it better. def foo(): var_a = 2 var_b = 3 def _closure(x): return var_a + var_b + x return _closure localClosure = foo() # Local closure is now "return 2 + 3 + x" a = localClosure(1) # 2 + 3 + 1 == 6 # DO SO...
I'm interested in what tools and methods are used for diagnosing flaws in large scale functional programs. What tools are useful? My current understanding is that 'printf' debugging (e.g. add logging and redeploy) is what is typically used. If you've done debugging of a functional system what was different about it then debugging a ...
It has been said that C# can be regarded as a functional programming language, even though it is widely recognized as a OO programming language. So, what feature set makes C# a functional programming language? I can only think of: delegates (even without anonymous methods and lambda expressions) closures Anything else? ...
I came across this answered question, but I can't seem to compile the code. I'm getting the following error on Seq.cast: error FS0039: The value, constructor, namespace or type 'cast' is not defined. I'm using Mono 2.0.1_1 and F# 1.9.4.19 on leopard. Is there something funky with f# when running under mono? ...