let string1 = "Hello"
let string2 = "world"
/// Use @ to create a verbatim string literal
let string3 = @"c:\Program Files\"
/// Using a triple-quote string literal
let string4 = """He said "hello world" after you did"""
let helloWorld = string1 + " " + string2 // concatenate the two strings with a space in between
printfn "%s" helloWorld
/// A string formed by taking the first 7 characters of one of the result strings
let substring = helloWorld.[0..6]
printfn "%s" substring
The awesome part is helloWorld.[0..6] which creates a substring with characters 1 through 7.
@EBrown I think the currying of F# is both awesome, and distracting... It can severely hide function calls and confuse function calls from variables and similar. But the actual currying function is cool
This also applies more in general for F#, but true be told, I haven't used it that much. And only seens some examples here and there
I've heard that Haskell is not favoured any more, but if there is any truth in it?
But that is an issue with all languages. Some are highly appraised within some community, and some are not. And wars have been started on similar issues...
I've been using C# (with the non-wanted C++ / CLR variants combined) for some time, and I do believe it out trumps a quite a few languages. Have used a wide variety of other languages earlier (Java, C, Perl, Php, *Pascal), and have recently started using Python. But I must say that Python is growing on me.
And I haven't caught on why to use functional languages like F$ (or Haskell or OCaml or ...). They seem somewhat limited for most of the tasks I've been wanting to program, but YMMV
That seems true, yes. But it comes at a cost, which I don't see the need of paying, and that is changing anything into function calls or sequencing of command calls. It kind of reminds of LISP (or Prolog) if you heard of those.
Or to paraphrase some one I heard recently, when you have the same stream of data to be manipulated from start to end, a functional language might be a good fit for that task. But if you want to maintain state and change that, they don't fit at all.
Yes, and usually my issues doesn't match that requirement.
On an entirely different topic: I'm recalibrating my screen, and I'm wondering is your messages in the chat of a light blue tone, or more of a gray tone?
And is the white messages (all others) slightly off white, or bright white?
I can't decide if my main or secondary monitor is the 'correct' one!
for me: light grey/blue background, my messages are definitely blue, other messages are more off-white. But, I have no guarantee that my screen is correctly callibrated :)
Hmm... I wonder how to get them to be similar at least. (I'm by the way running on a Mac Mini (and the main monitor is Dell U2713H on Display Port, and the secondary is a Dell E175FP on VGA). Might be optimistic to get them to have similar colours...
Oh well... I've got to look into it tomorrow, I think. I like the brightness a lot better on my main monitor, it seems crisper and in general nicer. But whether it is 'correct', that is another issue. But it is a little annoying to have a different hue on my secondary monitor.
Well, there are four different types of constructs to hold a series of values (at least that I've seen so far): dictionaries, lists, sequences and arrays.
Arrays are mutable, and defined as: [| |], but sequences are not and are defined as [ ].
But haven't you then already answered your own question/issue. Or is there a difference in how access the [ ] versus the [| |]? If not, use the first for non-mutable arrays, and the latter for mutable arrays
I think I'll make it a question on one of the two when I have thoroughly investigated it.
let array2 = [| "hello"; "world"; "and"; "hello"; "world"; "again" |]
// modify an array element using the left arrow assignment operator
array2.[1] <- "WORLD!"
Even Microsoft's tutorial demonstrates precisely that arrays are mutable.
let array2 = [| "hello"; "world"; "and"; "hello"; "world"; "again" |]
// modify an array element using the left arrow assignment operator
array2.[1] <- "WORLD!"
To me it kind of makes sense that an array is mutable, as that is a list/sequence/whatever of mutable variables which I usually want to change, or sort, or do stuff with. And then you have the similar construct of lists, which is more of a predefined set of values... And that is naturally enough non-mutable.
To me, with a very limited F# knowledge, it seems like syntactic sugar that you can use [ ] when you want the functional non-mutable variant, and then use [| |] when you want a mutable variant.
The following C# methods take n bits and operates on them all in one pass.
// Sets n bits to zero at index i.
uint zerobits(uint x, int n, int i) {
return x & ~((uint.MaxValue >> (sizeof(uint) * 8 - n)) << i);
}
// Sets n bits to one at index i.
uint setbits(uint x, int n, int i) {
retu...
@EBrown And as a side effect for guys, like us, coming from other programming languages where most list structures are called arrays, it kind of seems strange to have both variants, and since we're used to arrays we immediately think of them as the base type. So when thinking of F# as a non-mutable functional language, it seems wrong to have arrays as the base, but really they think that lists should be the base structure? Do you follow me?
@EBrown In short: Your primes should be stored in a list, but if using sieves of erasthones you need to use an array to build it, and then convert it to a list!
@EBrown It looks quite nice actually! The only thing I'd really nitpick is that things like [x..y] are usually written as [ x .. y ] for more clarity, but it's more of a preference. Other than that, I'd say it's all good. :)
let rec fibsRec a b limit =
if a + b < limit then
let current = a + b
let rest = fibsRec b current limit
current :: rest
else
[]
// In main:
printfn "Solution to Project Euler 2: %i" (Seq.sum (Seq.filter (fun x -> x % 2 = 0) (1::2::(fibsRec 1 2 4000000))))
Which is to sum all Fibonacci numbers from 1 to 4000000 that are even.
HeHe... The only downside is that then you are touching in on the non-functional part. Menus, and user input like that, doesn't go hand-in-hand with functional languages, as I've understood it.
Is there a design pattern to differentiate when to use: Seq.sum ( Seq.filter (fun .... ) (1 :: 2 :: (list-generator))))))) versus 1 :: 2 :: (list generator) |> Seq.filter (fun ...) |> Seq.sum, that either of you know of?
@Quill Do you think they are written in Swift, already? Not objective-C? (And by the way, from the little I know both of them, Swift surely seems like the better of them.)
My guess would be that 80-90 % of the app store is obj-c, not Swift... But the figures are most likely rapidly changing towards Swift as Mac demands usage of Swift for newer OSs and frameworks, as you say.
Since I've been playing with F#, I decided to try my hand at implementing some of the Project Euler problems, and I've been having a blast doing it. (f#-is-fun)
So, I'm going to list all the Project Euler problems I solved to make things pretty clear:
Project Euler Problem 1: Multiples of 3 ...
I'm working on a project in which I take in a map of voters (Integer) and voting ballots (ArrayList) and decide the winner with different methods. After a week long struggle, I still can't get my pairwise election method to work. It is supposed to compare each pair of candidates and give a point ...
Since you seem to be asking for review of existing, working code; codereview.stackexchange.com would be a more appropriate site to post on — M.M55 secs ago
I am calling a service outside of my control. My application must include a time out, so that if the call to the service takes too long, an appropriate time-out message is returned.
// Client connected to remote service
RemoteClient Client = new RemoteClient();
private async Task<MyResult> Chec...
I want to have a thin wrapper (low overhead) around c-style string. Also, with some additional features like equals and lt operators for map indexing. I have come up with the following class.
Can somebody comment on it?
From what I've gathered this class would take only as much memory as pointe...
"shit" being relevant to whatever I'm hiring you to do.
But even there, if I believe you could be taught the specific stuff you need to transition to a specific job without too much trouble, I'd take you anyway
Main reason why investment funds prefer to hire mathematicians over economists, because it's much easier to teach finance to a maths guy than the other way around.
I'm going through the Introduction to Algorithms book on my own, and I can't seem to figure out where I mistranlated the book's pseudocode into C#.
using System;
class mergesort
{
static void Main()
{
int[] nums = { 5, 4, 3, 2, 1, 0 };
Console.Write("Unsorted array cont...
I'm not trying to suggest a narrow definition of what "getting stuff done" encompasses, I'm trying to articulate that, IMO, you should decide what kind of traits an effective person in your role would exhibit, what they actually need to know, if there is indeed a minimum amount of required knowledge, and then forget any other requirements you might want to throw in in favour of hiring the person who will actually achieve the results you ask them to.
I have an input field that cannot have an integer inside, and an additional element beside it, the (younger-sibling element), cannot have an integer more than or equal to the other.
So I wrote a checker to check incoming keyCodes on keyup.
var nanReplacer = function(e){
if (isNaN(String...
@IsmaelMiguel I hate that point where it's like "I should go to sleep, but at this point, if I go to sleep now, I'll probably just oversleep. welp, I guess it's another all-nighter then"
@Zak The problem isn't that. The problem is that I lay in my bed and there's nothing good in my head, which prevents me to sleep. And when I finally sleep, it is almost 6AM
The following C# methods take n bits and operates on them all in one pass.
// Sets n bits to zero at index i.
uint zerobits(uint x, int n, int i) {
return x & ~((uint.MaxValue >> (sizeof(uint) * 8 - n)) << i);
}
// Sets n bits to one at index i.
uint setbits(uint x, int n, int i) {
retu...
Since I've been playing with F#, I decided to try my hand at implementing some of the Project Euler problems, and I've been having a blast doing it. (f#-is-fun)
So, I'm going to list all the Project Euler problems I solved to make things pretty clear:
Project Euler Problem 1: Multiples of 3 ...
I want to have a thin wrapper (low overhead) around c-style string. Also, with some additional features like equals and lt operators for map indexing. I have come up with the following class.
Can somebody comment on it?
From what I've gathered this class would take only as much memory as pointe...
I'm going through the Introduction to Algorithms book on my own, and I can't seem to figure out where I mistranlated the book's pseudocode into C#.
using System;
class mergesort
{
static void Main()
{
int[] nums = { 5, 4, 3, 2, 1, 0 };
Console.Write("Unsorted array cont...
I have an input field that cannot have an integer inside, and an additional element beside it, the (younger-sibling element), cannot have an integer more than or equal to the other.
So I wrote a checker to check incoming keyCodes on keyup.
var nanReplacer = function(e){
if (isNaN(String...
