/dpt/ - Daily Programming Thread

First for JavaScript

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>F#

Answer quickly: Why haven't you designed your own language, yet?

>>57208723
best langugae

>>57208734
not bothered

>>57208734
>>57208741
oh wait.. i did...

I worked out a TypeScript CoffeeScript hybrid, was gonna call it ToffeeScript.. but that's taken. Was going to mod the CoffeeScript compiler to make it, but gave up. Would basically just compile ToffeeScript (CoffeeScript with type annotations) to TypeScript.

I wrote a compiler!

https://github.com/expeditiousRubyist/bfc

>>57208734
>

procedure Values is
    -- About numbers and ranges. Not including the more obvious features for brevity.

    I : Integer; -- range: implementation defined => similar to 'int' in C

    type Full_Natural is range 0..2**32-1; -- Note the 'type' instead of 'subtype'. 
    FN : Full_Natural;
    type Unsigned_Int is mod 2**32; -- Mod types are utilized as bit-fields or counters
    UI : Unsigned_Int; -- wrap around value, equivalent to 'unsigned int'. Will not raise Constraint error or overflow exeptions
    -- You can see these types have equivalent range, but their behavior differs.

    -- Complex types
    subtype Letter is Character 
        with Static_Predicate => Letter in 'A'..'Z' | 'a'..'z'; -- provides enumeration over a non-continuous range
    subtype Even is Integer
        with Dynamic_Predicate => Even mod 2 = 0; -- This type is only even, ever. NOT and enumeration.

    C : Character; -- enumeration with range of 0..255, holds characters. Not equivalent to 'char'
    S : String(1..5); -- Strings are packed arrays of characters, cannot grow or shrink. NOT null terminated

    type Byte is new Integer range 0..255 with Size=>8;
    type Small_Array is array (0..3) of Byte;
    W : Small_Array;

    procedure One (Input : in Positive); -- TRUE limit of only positive range input, unlike 'unsigned'
    procedure With_Even (Input : in Even); -- Limits input to only even numbers.
    function Unsigned_to_Signed is new Ada.Unchecked_Conversion(Source=>Unsigned_Int, Target=>Integer);
    function Arr_to_Unsigned is new Ada.Unchecked_Conversion(Source=>Small_Array, Target=>Unsigned_Int);

begin

>>57208804

begin
    C := Character'Val(I); -- since character is an enumeration and not a numeric, 'Val must be called to convert
    I := Character'Pos(C); -- 'Pos must be called to get the postition of character C
    -- if Character is not a number how would you do something like converting to lowercase
    -- in C : char lower = c + 32; 
    Lower := Character'Val(Character'Pos(C) + 32);
    -- This is clunckier obviously, but this treats characters like letters, and not numbers.

    -- Enumerations can be looped over, this provides cleaner logic
    for X in Letter loop
        null; -- Also, the ordering and numbering are the same as Character since it is a subtype
              -- So the above tolower function also works
    end loop;

    C := S(3); -- Strings are arrays of characters, so S(#) returns a character
    S(1..3) := S(3..5);

    -- Bit manipulation
    UI := 16#FFFF0000#;
    UI := UI or 4;
    -- However 
    I := I or 4; --is illegal, bitwise operations are only legal for mod or Boolean types
    UI := UI or I; -- is also illegal
    UI := UI or Unsigned_Int(I); -- is legal, though constraint error will be raised if I is negative

    --Finally, how to move your bitfield into a numeric.
    I := Integer(UI); -- legal, but unsatifactory. will raise exceptions when UI > Integer'Last
    -- we must call the generic function Unsigned_to_Signed 
    I := Unsigned_to_Signed(UI); -- This ignores all checks. identical to 'i = (int)ui' in C
    -- Note that a conversion to a type that doesn't make full use of the allocated bits may raise
    -- exceptions or produce an invalid number. IE Unsigned_Int to Positive.

    -- time for implementation defined behavior!
    UI := Arr_to_Unsigned(W); -- identical to ui = *((unsigned*)w);
    -- Ada arrays are not guaranteed to be continuous
    -- Thankfully gnat implements them as continuous structures so this is safe.
    -- honestly this is unlikely to be of much benefit since passing arrays is valid in Ada, and guaranteed to be safe

end Values;

>>57208696
I'd use F# if it had better support in the .NET world. I'm not really a big fan of ML-like languages in the first place, and the only reason to adopt a .NET language is for the superb support Microsoft gives it (e.g., C#). As it is, it feels like Microsoft intends it to be a little-brother language to C# instead of a language in its own right; you just wrap F# components in C# or other .NET languages, and I really don't have much interest in C#.

Anyone using rust at all? It seems cool but it's fuckin weird and confusing at points.

>>57208826
>I'd use F# if it had better support in the .NET world
you mean in terms of tooling?

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Which FRP frameworks in Haskell are good for games? I want to make some simple game for fun, like boulder dash or pitfall clone or whatever.

>>57208856
Yes.

finished a databse
you can add assertions
you can use AND and OR and make rules, and do comparisons if assertions have numeric data

anything else that's cool and i might wanna add?

>>57208873
The tooling isn't as refined as C#, but it's not bad either.

Don Syme seems to want to keep F# a much more open source community project than C#.

Writing an SQLite-backed app which needs to sync across multiple devices and platforms. Looks like I need to use UUIDs instead of (or as well as) autoincrement integers for ID fields, store both a master reference DB and per-device DBs in the cloud, and use something like sqldiff to generate changesets in the correct order when there's an update. Does that sound about right? Anyone here done this before?

>>57208868

https://wiki.haskell.org/Game_Development
https://www.reddit.com/r/haskell/comments/1kxo0i/game_programming_and_frp/

Hows little schemer for first time ?
Gonna play around with it tomorrow.

>>57208950
>Gonna play around with it tomorrow.

>gonna
>play around

>play
>around

>tomorrow

wrong attitude

>>57208758

>ToffeeScript

Oh shit, my sides...

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Been writing the textboard some more, added board and thread deletion It's been really fun, hopefully this turns in to an actual project.

>>57208835
Nope. Rust is not production-ready just like Haskell.

>>57209114
Haskell powers SpaceX's Dragon 2 capsule

>>57209143
>Haskell powers

>>57209143
Being used in 2-3 projects worldwide does not mean it's ready for production.

>>57209143
Source please, google has nothing.

>>57209184
I lied. No one used haskell except for meme research projects.

>>57209088
What's the CSS like to get those shadows? It looks kinda neat but I'm not convinced I like it. I wanna mess around with something similar.

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Obligatory

You guys thought I sleep but I don't.

>>57209205
box-shadow

https://developer.mozilla.org/en-US/docs/Web/CSS/box-shadow

>>57209201
This is the problem with useless language proponents. They do nothing but try to shit on Haskell all day.

>>57209205
I used this page:

http://www.cssmatic.com/box-shadow

I don't think it's something that'll stay, but I'm not a designer so I'm not really good at making nice looking things.

>>57208895
Yeah, it's good enough that it stands out, but it doesn't seem good enough to be worth swapping to unless you're already a C#/.NET developer. Maybe in a year or so. I do think it has a lot of potential though, for all the shit Microsoft gets, they do a really good job at making developing in "their" languages and environment pleasurable.

>>57208950
It's good. It ramps up in difficulty a lot around 1/2 to 3/4 of the way through, but it's quite good.

>>57208696
>OOP
>FP
OK, what's other good concept to try after those?

Here is a list of the most controversial words in /dpt/ (number of replies):
http://pastebin.com/QxRa7CC4

I think I'll stop now.

>>57209283
What would you be swapping from?

>>57209302
dynamic typed

>>57209233
>>57209275
Thanks! Looks like it could be pretty good for some things if you use a more subtle, even shadow like:

-webkit-box-shadow: 3px 3px 15px 1px rgba(0,0,0,0.6);
-moz-box-shadow: 3px 3px 15px 1px rgba(0,0,0,0.6);
box-shadow: 3px 3px 15px 1px rgba(0,0,0,0.6);

https://twitter.com/joelgrus

reminder that python is the language of patriots

>>57209329
Racket Lisp. The tooling & support is about what you'd expect from any not-corporate-backed language (I.e. emacs), but the language is such a genuine pleasure to work with that I really haven't felt any burning desire to swap to another language.

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If I have a C# visual studio project with .dll dependencies that I wanted to deploy onto Linux with minimal effort on my part, what would be the best way to go about it?

This is the most efficient insults so far:

quadcopteranon      405.00000
amerinewfriend  388.00000
untimely        356.00000
tumblers        356.00000
redmemes        356.00000
motherload      356.00000
goodboypoints   351.00000
softwaredevelopment341.33333
reverseengineering341.33333
macroshots      338.00000

>>57208696
worked all day on this and it finally works
http://pastebin.com/DafiGB2a

feel free to use it, or critique my code I know its a tad sloppy but its an impressive time saver

(no autists please)

>>57209551
Why beginners need to make things so complicated when it's actually simple?

>>57209518
don't use .dll dependencies that rely on windows specific stuff. make sure they all work okay on mono.

>>57209631
As far as I know they don't rely on anything windows-related. They're just a dll that lets me format my flags easier and a dll that lets me parse HTML easily.

>>57209518
Depends on what the DLLs are.

>>57209649
Then compile them for Linux and link statically.

>>57209649
Well, i guess just compile it, run it on mono on linux and see if anything goes wrong.

Is it just a console application? It might work perfect on the first go.

>>57209690
This is C# m8

I don't understand how the lisp system works
all I want is to use the cl-charms package
but its a fucking chore to do so

I already did ql:quickload "cl-charms" in sbcl (which is the worst interactive program I've ever used)
now, how do I import it and use its functions
where do I look at the available functions in the package (seeing as sbcl can't even complete)

pls help, I'm trying to get productive, but this ambiguity is fucking me over

>>57209733
Then why are you even asking, if your DLLs are also in C#?

>>57209774
C# can have dependencies that mean it won't work on mono but will work on windows.

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>tfw too intelligent to use C

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>>57209896
>tfw too intelligent to learn Haskell

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Is what they're asking here any different from writing functions that add onto the head or tail of a list, and deleting from the head or tail of a list?

Like I could just change the name of a addToEndOfList() function
to enqueue() and it would be right, wouldn't it?

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>try hackerrank
>get question about counting binary contiguous substrings in a string >number of zeroes equals number of ones in the substring, e.g. "01", "1100", "000111")
>can't solve it in 60 min
>tfw life failure

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>write API
>everything's organized into nice simple use-cases

>write GUI
>clustfuck of fuck

>>57209925
Pretty much. Just be careful that you get the LIFO and FIFO behavior these operations should have.

>>57209925
you don't need to do much more work, no. but it's a decent test of your knowledge
for example, if you were iterating over the whole list while performing one of these tasks then that would be a bad sign to me

>>57209975
git gud

Is there a way to make a GUI in C without libraries? I don't care about cross-platform.

>>57210030
>without libraries
You are already using libc. "without libraries" really doesn't make sense.

>>57210030
what platform?

whats the equivalent of c's #include in common lisp with clisp or sbcl??

>>57209975
Read up on UI design then

>>57210053
>

>>57210054
Linux. Is this WM dependent?

https://medium.com/@AdShadlabs/why-you-should-never-use-upwork-ever-5c62848bdf46#.1n597kqcn

any experience with this site? just curious

>>57210072
you can dynamically link into gnome for UI, which i think is what you want?

>>57210120
Yes. Exactly this, I just need the GUI to work on one computer

>>57210072
>Is this WM dependent?
No. You could talk to X directly or use glut and opengl.

>>57210162
>glut
Is there something like this for Vulkan?

Holy shit python is such a fucking meme language.

I went around calling it a meme language before I tried using it but I didn't realise how much of a meme it is.

You can make a string and then slot an integer in it and then make the integer huge and it will just expand the memory space and then you can make it a string and multiply it by a number.

How is anyone supposed to take it seriously?

>>57210175
not that I'm aware of. Probably not.

Do you really want to make UI that only works on Linux with Vulkan drivers?

>>57210196
You're a meme.

set(1,3, 6) - set(3, 2) # =[1, 6]

>>57210175
I don't know. But glut sucks anyways.
It's fine for simple things and learning.
When you get to the point that going down the Vulkan rabbit hole makes sense, I guess that something like only gets in the way.

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will trump remove pajeet?

>>57210235
source of screenshot?

>>57210218
I don't want to make a real GUI though (implying buttons, menu and what not). Just an interactive graphical interface.

>>57210226
Is this a good alternative?
http://freeglut.sourceforge.net/

What do you mean by "Vulkan rabbit hole"? I don't see what's wrong with it

>>57210250
>not being on the list

>>57210196
sounds expressive

>>57210262
>Just an interactive graphical interface.
involving what exactly? You can just use raw vulkan if you like.

>>57210284
Basically, I want to make a program that generate music and you control the output with a visually explicit interface.

I didn't know you could use raw vulkan...
I'm going to test those:
https://github.com/SaschaWillems/Vulkan/

>>57210322
why not just use a normal GUI? you making things thousands of times more difficult

>>57210334
muh *cough* learning purpose *cough*

>>57210322
Just use Qt or Gtk.
Rolling up your own thing in OpenGL, SDL or whatever is going to look like shit and be a lot of fucking work.
You can embed freely drawable canvases in those if you need to do something special.

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>emailed prof last night about a problem i had on my assignment, 2nd time i've emailed him about this assignment
>solved it this morning and was about to email him when he emailed me how to fix it
>told him thanks and how funnily enough i fixed it right before he emailed me
>just now, 6 hours later, he emails me saying to not respond to emails he sends unless it's important, because it clogs up his inbox

>>57209180
Indeed. A language has to be in use by millions of pajeets to be considered ready for production.

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I just decided to make an iOS app next weekend.

Does anyone have an opinion on whether I should use Swift or Objective-C?

I want to use whichever language makes me look more employable.

>>57210471
swift is the future. just do that

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What's the best INTERPRETER for C++. Not compiler, mind you. I'm using Codeblocks and it's becoming a pain in the ass constantly deleting and recreating the compiled file after I change it. I just want something to make quick changes to a file before it's compiled.

>>57210501
aight

>>57210564
We used this at CERN
https://root.cern.ch/cint

>>57209740
this is the same thoughts I got the first time I even tried to learn something about the language...

people use Racket, not sure the diff, but apparently it's better. don't ask me anyway, never got to learn lisp

>>57209975
UI design sucks

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Employed Haskell programmer reporting in

>>57210803
katie??

>>57210803
What language do you program in for work?

>>57210803
400k starting???

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>>57210831
Haskell of course

>>57210803
how much $$ and do you want to kill yourself

>>57210564
cling

>>57208762

wew

>>57210928
I know this is a dumb question, but how do you download it. I tried running the script in cmd but nothing happens. Please help.

>>57210896
thanks but i dont think it works for counting strings with more than one char

>>57211025
https://msdn.microsoft.com/en-us/library/tabh47cf(v=vs.110).aspx
this should be enlightening re: why it isn't working and how to make it work
but the problem is that the very definition of this .Split method involves arrays as input and output, so this is probably not what you want

>>57209740
I don't use Common Lisp, but shouldn't they already be loaded after using quickload? Try running some of the procedures. Or look at a QuickLisp FAQ.

>>57210796
In Racket Lisp you just (require package-name) and then use the defined functions/procedures.

>>57209690
I'm not the one that compiled the .dlls and I have no access to the source code

>>57209724
It is. I'll give it a shot, but doesn't mono need special params to include dependencies in the resulting binary? I know that to package the .dlls into the executable instead of requiring them to be in the folder in VS, I had to use a nuget package to get it all together, wouldn't I need something similar for Xamarin?
I don't know linux very well but I'm almost certain that DLLS are a windows only thing and that it wouldn't be able to load them from the dir.

>>57210954

Whew
https://github.com/expeditiousRubyist/bfc/commit/8660b4fcc24f11993d43e1ff6753c6b5fc000078

It runs on my Pi now.

>>57209925
>Is what they're asking here any different from writing functions that add onto the head or tail of a list, and deleting from the head or tail of a list?
yeah, stacks and queues are just a specialized form of linked list, but only if your linked list already keeps track of head/tail for constant time access, otherwise it's not a stack/queue.

>>57211025
Then you basically have to iterate over the string.

When the first character of string a matches the first character of string b, you look at the following characters in string a and see if they match string b. If they do, increment your count by one.


>>57211089
Holy shit I am one dumb motherfucker.

Although there should be a goddamn string.Split(string x) overload

>>57211089
>>57211209

            string source = "abcdefgabcd";
            string sub = "abc";
            int count = 0;
            int n = 0;

            while ((n = source.IndexOf(sub, n)) != -1)
            {
                n++;
                count++;
            }

thanks anyways guys
found this btw, seems like a simple way to do what i want

>>57211254
there are so many methods that it's hard to know what's "cheating" here
here's something to consider: suppose i ask you to search the string "xxx" for "xx". is the answer supposed to be 1 or 2?

>>57211304
yeah i think it doesnt make sense for it to be 2 like that code outputs

ill try the other way (unless i fall asleep before)

i'm going to a local highschool (the one i graduated from desu) to do a coding seminar for the children. how should i set it up? their school uses windows xp. should i get them to download virtualbox and ubuntu or what? also what language should i teach them in? it's only going to be an hour long with 3 sessions. i think the school uninstalls all installed programs at the end of each day too

Do you have to be a little bit autistic in order to become a good programmer?
I was always interested in programming but never got around to try it until now.
I started reading a book about C my friend gave me and holy shit it's interesting but I don't think I can enjoy this.

>>57211423

>Do you have to be a little bit autistic in order to become a good programmer?
Yes.

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do you guys like any software-related podcasts?
everyone loves this shit but i've yet to find one i can stand

>>57211423
if you want to have fun programming, i'd recommend write scripts for stuff you actually want to do. or play hacking games

>>57211455
>Projecting

Have implemented some basic random tree shenanigans until I found out that I did not yet fully get it.

Now I'm watching machine learning lectures on YT while I wait for my callus ointment to be absorbed well enough to go to bed.

>>57211548
>random tree
what are you trying to do?

>>57211548
>machine learning lectures
nice, which ones?

>>57211458
software dev podcasts where at?

r9 script for a hack game where you have to brute force a 4 digit pin

#!/bin/bash

for a in `seq  0 9`;
do
  for b in `seq 0 9`;
  do
    for c in `seq 0 9`;
    do
      for d in `seq 0 9`;
      do
        echo "UoMYTrfrBFHyQXmg6gzctqAwOmw1IohZ" $a$b$c$d | nc localhost 30002
      done
    done
  done
done

>>57211423
>Do you have to be a little bit autistic in order to become a good programmer?
No, not at all.

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Currently trying to do an implementation of the Knights Tour using Recursive Backtracking.

My solution gives me an answer fairly quickly for a 7x7 grid, but when I do an 8x8 grid, it takes a lot longer (I haven't ran it for l... Is this expected for an unoptimized version of the algorithm?

Here's the main function:

struct Knight{
    int xPos;
    int yPos;
    int moveNum;

    Knight(int x, int y, int n)
    {
        xPos = x;
        yPos = y;
        moveNum = n;
    }
};
bool knightsTourHelper(Knight& currentKnight, Grid<int>& chessBoard)
{

    /********* BASE CASE **********/
    if(currentKnight.moveNum >= NUM_OF_SPOTS_IN_GRID -1 ) //If you've moved more times than there
        //are spaces on the chessboard, then congrats, you've completed the tour!
    {
        cout << "SOLUTION FOUND! #: " << currentKnight.moveNum << endl;
        printGrid(chessBoard);
        return true;
    }
    /********* RECURSIVE CASE **********/
    else
    {
        Vector<int> validMoves;
        returnValidMoves(currentKnight, chessBoard, validMoves);

        int changeX, changeY;
        for(int direction: validMoves)
        {
            chooseKnightMove(direction, changeX, changeY);
            Grid<int> chessBoard_COPY = chessBoard;
            Knight currentKnight_COPY(currentKnight.xPos + changeX, currentKnight.yPos  + changeY, currentKnight.moveNum + 1);
            placeKnight(currentKnight_COPY, chessBoard_COPY);

            if(knightsTourHelper(currentKnight_COPY, chessBoard_COPY))
            {
                return true;
            }
        }
    }
    return false;
}

And here's the github if you need to see the guts of my program: https://github.com/CubicProgramming/ProgrammingChallenges/blob/master/KnightsTour

Hey /g/

Supposed you have a stream in scheme, and you want to filter it to produce another stream which contains a subset of the initial stream. How do you do this if the filter is defined such that the intersection of values between f(s) and s is the empty set, while avoiding an infinite loop? e.g. consider a stream of all natural numbers, and two filters which produce either the set of all even numbers, or the set of all odd numbers, and then producing a stream which is the composition of those two filters.

>>57211423
>holy shit it's interesting but I don't think I can enjoy this.
then it's probably not for you

>>57212094
>Is this expected for an unoptimized version of the algorithm?
Yep. The basic backtracking algorithm for knights tour becomes very slow very quickly right after 7x7. You can read the Wikipedia article on it if you like.

>>57212260
Okay. Thanks for the response, but I'm a bit concerned, because it takes almost no time to run the 7x7 grid, yet I could listen to Starless by King Crimson in its entirety, and the 8x8 still didn't work...

On that note.... What's the time complexity on this backtracking solution? I want to say Worst case O(8^n)

Stumbled upon a Material Palette color picker which was made with Electron.

https://github.com/mike-schultz/materialette

At 40MB for a standalone executable, I think its a little too heavy, and decided to write a Python one.

https://github.com/altbdoor/py-material-palette

>>57209551
wew lad

>>57211304
actually just changed i++ to i += sub.Length and it now works like i wanted it

so in git, say im rebasing in unpushed local history because i messed up a previous rebase but i actually want to add a new commit in history that would follow that commit but still include all commits that would have come after

how do i go about doing that, its hard to word into a google search

>>57212298
>>At 40MB for a standalone executable, I think its a little too heavy

Have you thought about getting a job so you could afford more space.

>>57212294
>I want to say Worst case O(8^n)
All that matters is that it's exponential, so it's going to grow stupidly quickly with the size of the inputs.

>>57212679

Letting the executable fit in cache and not having data marshaled from RAM killing performance is a good thing.

>>57212679
great mindset, faggot. because of people like you, tech advancements gets completely destroyed by shitty, bloated apps

>>57212757
But from 5, to 6, to 7, the runtime was all well below one second... I'm just having a hard time understanding what causes the massive jump in time... I understand that it's exponential, but it's a fairly small increase in size so I do expect a non-arbitrary scaling of the time required to run, but this is a bit ridiculous....

Sorry for the dumb questions

>>57212876
have you attempted to time it exactly?

>>57211847
truly inspiring anon
>>57211402
No they almost certainly don't need a virtual machine, I would just have them python with an IDE (e.g. pycharm). Maybe you could set up a little script to do it for them

>>57212876
>I understand that it's exponential, but it's a fairly small increase in size so I do expect a non-arbitrary scaling of the time required to run, but this is a bit ridiculous....
This is the answer to all you retards wondering where you'll need math for CS.
It seems you're even copying chessboards each time which is also pretty slow, and the operation will grow O(n^2).

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>>57212892
Here's some information I just got

What does this code do assuming x is an integer?

x = x & (x - 1);

recommend me a not shit language for scripting. i tried bash and php and they both gave me ass cancer. i know C, >Java, and Scheme. i'd like to use scheme if it's possible but idk how. how do i run .scm files like i would shell scripts on the command line? e.g. echo something > myscript.scm > output.txt

>>57213117
Makes x even.

>>57213255
I'm wrong, it sets x to 1 if it's a power of two.

How do you use mmap()?

#include <stdio.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/mman.h>

int main(int argc, char *argv[]){

  int argInt = atoi(argv[1]);
  FILE *fp;
  int i;
  char *addr;
  fp = fopen("results.dat", "w");
  for (i=0; i<=argInt; ++i)
    fprintf(fp,"%d\n", i);
  addr=(char*)mmap(NULL, 4096*argInt, PROT_READ,MAP_SHARED, fp, 0);
  char count;
  for (int i=0;i<argInt;i++)
    {
       count=addr[1];
    }

}

My homework is im supposed to produce major page faults at a predictable rate based on the argument. So I tried this, I want to just read the file as a character array but how do I do that? This segmentation Faults.

>>57213270
Thanks for your answer man. It's part of a lecture slide my professor posted and I couldn't figure out what it was supposed to do.

>>57213270
do you mean to say something else?
if, say, x = 2 you calculate 10 & 01 = 00 right?

>>57213290
>(true-val) if (cond) else (false-val)[/code]
God damn, python ternary expressions are fucking retarded.

>>57210196
is that like the printf thing

>>57213422
i think he meant to say it sets x to 0 if it is a power of two, otherwise it sets it to a positive integer. hence, you can do this:

bool is_pow2(unsigned n){
return !(x & (x - 1));
},

so (x & (x-1)) actually tests if it is NOT a power of two, since all non-zero integers are treated as true.

>>57213508
er. that should be

_Bool is_pow2(unsigned n){
    return (n != 0) && !(n & (n - 1));
}

also, it falsely returns true for 0, so you probably wanna account for that

>>57213366
nvrm

>>57213221
you need to run the interpreter on it. if you're using Guile, for example, guile script.scm. guile also lets you do

#!/usr/bin/guile
#!

at the top of the file to run it with ./script.scm. I'm sure other implementations let you do that too but idk the syntax for them. just look up "<interpreter> shebang" on Google

File: 1451443644060.png (92KB, 310x356px) Image search: [Google]

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>File IO in Java

>>57213862

writer = new BufferedWriter(new OutputStreamWriter(new FileOutputStream("filename.txt"), "utf-8"));

Do Java people actually find this acceptable?

>>57213889
in haskell this is just

readFile "filename.txt"

>>57213954
>read
Haskelltards retarded as usual

>>57213959
reading and writing is basically the same but backwards

>>57214005
Right, that doesn't mean you can just substitute write for read, retard.

>>57214015
I was confused by all the fucking writing and it just blocked my brain with noise

>>57214015
it's actually

writeFile "filename.txt" str

you could write a kind of monadic io for file manipulation though

>>57213889

writing them all in a single line is pretty gross, why not separate them into separate lines?

>>57214029
I know this is absolutely crazy, but what if, just what if they had a sane file IO inteface in the first place? You know, like everything other language?

>>57213889
You could always just use the plain FileOutputStream, but that would require you to not be braindead.

>>57214166
>byte oriented stream
Yeah, this totally isn't pointlessly limiting at all.

>literally the only alternative to using the clusterfuck disgusting interface is by using the low level featureless interface.
Sasuga Java.

I've done x86 kernel and bootloader programming, so don't tell me that I'm too dumb to use the lower level interface, because that's dead wrong.
Forcing yourself to use such low level interfaces when you do not need it in what's supposed to be a high level language is just plain fucking retarded.

>inb4 >low level
Yes, compared to the interfaces that the language should provide (in a sane way), it is low level.

Kill yourself.

>>57211134
If you don't have sources of the DLLs or libraries that have been compiled for Linux, you can't. You need to replace your dependencies with something cross-platform.
>>57213221
Python or Go.

>>57209518
You'd need to write the "DLLs" for Linux that do not rely on WinAPI.

Oy. What are the cases where '==' does not return true even thoush hashcodes for two objects are equal? In java

>>57214739
because it probably attempts to compare the objects of strings/digits that are returned rather than the actual values

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>strlen reads until \0
>forgot about it
>expect it to read until the last ascii character instead
>program would spout garbage every few strings
finally fix'd
here's the skeleton for my chink cartoon streamer
imma add file seek and mp4 stream header posting per thread later
http://pastebin.com/CpKACKDL

>>57214771
>thread per connection
disgustingly inefficient

>writing a streaming software yourself for no reason
https://github.com/arut/nginx-rtmp-module

>>57214778
>trying this hard
calm down man, this is for fun, you dont need to impress online strangers with your programming knowledge lol

>>57214768
Interesting.
Can it be related to me having overriden the toString method for that particular object class?

>>57214790
yes, because even though the values stored are equal the method itself, having been overridden, is not. not sure how java deals with it but that's why === exists in js.

>>57214835
I see. Cheers.

Is there a way to remove an element from a list if a certain element has a particular letter or punctuation?

Sort of like x = [i for i in list if len(i)==2] but instead y = [z for z in list if '.' present]

Using python3 atm

Also if theres a better way to do this please do share, I have no idea what I'm doing

dirs_and_files = """
        # CREATE DIRECTORIES FIRST
        site
        site/app
        site/app/controllers
        site/app/models
        site/app/views
        site/app/views/layouts
        site/app/views/users
        site/config
        site/db
        site/log
        site/public
        site/public/images
        site/public/javascripts
        site/public/stylesheets

        # THEN CREATE THE FILES
        site/app/controllers/posts_controller.py
        site/app/controllers/users_controller.py
        site/app/models/post.py
        site/app/models/user.py
        site/app/views/layouts/application.html
        site/app/views/users/account.html
        site/app/views/users/index.html
        site/app/views/users/signin.html
        site/config/routes.py
        site/config.yml
        site/db/site_db.sqlite
        site/db/site_db.sqlite3
        site/index.py
        site/log/access_log
        site/log/access_log.txt
        site/log/error_log
        site/log/error_log.txt
        site/public/stylesheets/style.css
"""

>>57214944

y = [z for z in list if '.' not in z]

>>57214956
Err you wanted it to contain the dot so get rid of the "not" and just leave it at "if '.' in z".

>>57214966
>>57214956
Thanks senpai

Why can't I compile a program using Bullet Physics?

configure.ac

PKG_CHECK_MODULES([bullet],[bullet])

src/Makefile.am

myapp_CFLAGS = ... ${bullet_CFLAGS}
myapp_LDADD = ... ${bullet_LIBS}

$ LC_ALL=C make
make  all-recursive
make[1]: Entering directory '/home/me/Utveckling/myapp'
Making all in src
make[2]: Entering directory '/home/me/Utveckling/myapp/src'
depbase=`echo engine/PhysEngine.o | sed 's|[^/]*$|.deps/&|;s|\.o$||'`;\
g++ -DHAVE_CONFIG_H -I. -I..     -g -O2 -MT engine/PhysEngine.o -MD -MP -MF $depbase.Tpo -c -o engine/PhysEngine.o engine/PhysEngine.cpp &&\
mv -f $depbase.Tpo $depbase.Po
In file included from engine/PhysEngine.h:4:0,
                 from engine/PhysEngine.cpp:1:
/usr/include/bullet/BulletCollision/btBulletCollisionCommon.h:22:64: fatal error: BulletCollision/CollisionDispatch/btCollisionWorld.h: No such file or directory
 #include "BulletCollision/CollisionDispatch/btCollisionWorld.h"
                                                                ^
compilation terminated.
Makefile:479: recipe for target 'engine/PhysEngine.o' failed
make[2]: *** [engine/PhysEngine.o] Error 1
make[2]: Leaving directory '/home/me/Utveckling/myapp/src'
Makefile:364: recipe for target 'all-recursive' failed
make[1]: *** [all-recursive] Error 1
make[1]: Leaving directory '/home/me/Utveckling/myapp'
Makefile:305: recipe for target 'all' failed
make: *** [all] Error 2

>>57215229
Oops, missed a [/code]. Oh well, you get the problem.

>>57215229
Mostly because you're swedish, did you remember to #include <cuckshed>?

Anyway, the error says
>fatal error: BulletCollision/CollisionDispatch/btCollisionWorld.h: No such file or directory

Check if that's true.

>>57215328
Forgot to point out that I've installed libbullet-dev, and verified that every file exist.

$ ls /usr/include/bullet/BulletCollision/CollisionDispatch/btCollisionWorld.h
/usr/include/bullet/BulletCollision/CollisionDispatch/btCollisionWorld.h

Editor question:
In Vim, is it better to use a filetype file in ".vim/ftplugin" or add an "autocmd FileType" in my vimrc?

>>57215366
>/usr/include/bullet/
Do you include that directory in your search path for header files?

>>57215477
Yup,

-I/usr/include/bullet

is added to the cflags. I'm able to include the file I'm trying to include, but it itself cannot include further files.

>>57215372

Never mind, apparently it doesn't matter on a computer built after 1990.

https://go.googlesource.com/proposal/+/master/design/17503-eliminate-rescan.md
>Austin and Rick's latest proposal to improve the #golang GC aims to reduce worst-case STW time to under 50µs (!!) --@enneff

>>57208956
what should it be desu?

is strong typing required for equational reasoning

>>57215229
>>57215236
Oh, bloody hell! I was using

myapp_CFLAGS

when I should've been using

myapp_CPPFLAGS

.

>>57215573
it helps

What problems may experience a newbie later in life if his first language is JS?

>>57215731
>later in life
You're making a lot of assumptions

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https://www.youtube.com/watch?v=QS8qwMna8_o

Recommend good programming videos w/ talks or discussions as I take a break from programming (to eat oatmeal).

>>57209088
>no warning before deleting something
m8

Hi guys, I have a simple C question. What does it mean when a value of a function gets "returned to the calling routine"? I have a vague idea about it, but I want to make it concrete enough that I can explain it to other people. Thanks in advance.

>>57215763
>it's often better for me to be kind of a hermit

Don Knuth is a NEET

>>57215774

int average(int a, int b) { 
  return (a + b) / 2;
}

int func() {
   return average(2, 4);
}

in func, it _calls_ the function average
this goes into the body of average, and executes it
"return" jumps back to the previous place
"return x" goes back but takes a value x with it

so for instance, average would return 3 to the calling function (func)

>>57210471
everyone already switched to swift 1 year ago

>>57215799
Oh noice, thanks anon. That was a simple, yet effective explanation.

Just wrote a bash script to randomly select a new wallpaper for you from a directory whenever it is called, using Feh and i3.

>>57215799

Your average function is broken -- but, I'm not passing judgement.

It's impossible to average two (2) integers in C.

>>57216062
It's not broken it's just poorly named

>>57216062
>implying

float∞ average(int a, int b) { 
    float∞ a = 2;
    return ((long)a + b) / a;
}

>>57216112
no

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>>57216076
>It's stylistically designed to be that way, we can't undo that

>>57216112

Still wrong.

>>57216161
Nope. It's perfect. Find a single flaw.

>>57216112
>float∞
>∞
?

>>57216188
a float point number that is an infinite number of bits in length.

>>57216193
>>57216167

O(∞) time and space complexity

Is there anything better than that feeling you get when you finally solve that problem you've been having?

>>57216211
Can just lazy evaluate it, so it's fine :^)

>>57216167

Wrong brace style.

>>57208696

should I learn C++ as a hobby and hopefully gain some money one day?

i'm 28 btw

>>57216213
>Is there anything better than that feeling you get when you finally solve that problem you've been having?
I usually remain depressed, knowing how insignificant the problem is the grand scheme of things, that my body is decaying every second until it stops functioning in a few decades.

>>57216221
If you want money, learn C# or Java. But don't learn Java.

>>57216231
>>57216221
Learn C# is you want to work with Pajeet in non-free, freedom hating Microsoft shops.
Learn Java to at least have some chance of working with GNU/Linux.

>>57216226
The only good thing about life is that eventually ends. While you're alive you might as well enjoy it as much as you can by writing dank code.

>>57216245
>Java
>More free than C#
LOL.

>>57216231
>>57216231
>>57216259


why not C++?
C# is popular?

i want to learn Java too

>>57216275
>why not C++?
low demand
>C# is popular?
yes

>>57216285
>C# is popular?
>yes

aiight

>why not C++?
>low demand
i read somewhere thats it's the best language

>>57216309
A language being good does not mean that there's a lot of jobs for it.

>>57216309
>i read somewhere thats it's the best language
best for some things. Not best for what most industry jobs do.

C++ is good for very high performance stuff, it's not good for high productivity. Most industries prefer the productivity.

>>57216341

>C++ is good for very high performance stuff, it's not good for high productivity. Most industries prefer the productivity.

>>57216336
>A language being good does not mean that there's a lot of jobs for it.

thanks both you for your concise yet enlightening replies

C# and Java it is

>>57216341
>>57216285
Well, this is disheartening. I have always wanted to learn C++ after mastering C. Oh well, I will still learn it, but I guess I will have to learn Java/C# if I want work. Bummer.

>>57216426
If you're good enough you can find work in C/C++, but C#/Java is much much easier and better paid.

>>57216379
Your life is less useful than a ghost. You shouldn't be born is the first place.

>>57216112
This is not remotely accurate.
There is no world in which this would work.

>>57216456

I like when people just still your (You)s

>>57216477

thank you anon, and bless your parents for raising such a delightful person

>>57215751
Implying?

I'm implementing the Huffman compression on a text file in C

>>57216787
Okay.

>>57216787
Okay.

>>57216787
Okay.

any "Computer Scientist" in /dpt/ want to explain how React works in the virtual dom?

cs phds only please, I want a concrete answer, no buzzwords no fizzbuzzes.

>>57216869
>>57216887
>>57216899

faggots, show what you're doing.

>>57216275
last i checked HotSpot was open source, and C# was still by Microsoft.
you tell me which one is more free

>>57216969
ur mom

>>57216787
sounds interesting, post source when you're done

>>57216979
C# is more free.

>>57216983
wew, must be hard

>>57216985
I'm doing in real quick to see if it's working, I'll try to make the code more readable.

>>57216492
>no buzzwords
>phds only
Pick one.

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>>57216986
Yeah, I'm sure C#, developed by Microsoft, is going to stay nice and free, and that microsoft bought mono to help Linux :^)

>>57217112
> Linux doesn't already provide the best development tool

nice one

>>57211158
>stacks and queues are just a specialized form of arrays
ftfy

>>57217143
>C has dynamic array

>>57212839
why are you using words you don't understand?

>>57211158
>stacks and queues are just a specialized form of linked list
No. stack, queue, and list are abstract types. linked list is an implementation of the list abstact type.
You are confusing a concept and the implementation of the said concept.

>>57214232
>I'm literally retarded

>>57213889
yes, makes sense if you know most of the common IO techniques.

>>57217162
Because I'm using Thesaurus.

>>57217159
>I'm brain dead

>>57217222
Explain how you 'push' a value in a C array then faggot

>tfw have my first programming exam today

kinda freaking out desu

>>57217159
C has automatic arrays

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>>57217078
Final Destination
>>57216062

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>He still uses Perl

>>57217250
Don't worry, you're fucked anyway. Have fun with failing, kiddo, and welcome to real life.

>>57217231
>explain how assignment and increment works
you might be too dumb for this, m8

>>57217282

found the depressed virgin

>>57217250
you'll be fine anon, good luck!

>>57217295
explain how you push the value 5 in

int a[10] = {0};

>>57217250
Remember how to average two ints and prove that 30 + 30 = 60 and you'll be a-ok.

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>>57217280
Then what is the current goto write-only language?

>>57217231
struct arr {
int* data
int pos
int length
}

arr push(arr a, int val)
{
    if(arr.pos++ > arr.length)
         ;//realloc code here
    
    arr.data[pos] = val;
    return arr;
}

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>>57217275
>bloat

is there a way to view variables currently in scope in a C++ editor? i use kdevelop, have used qtcreator. i know i can run the debugger, but it would be nice if it could tell me which variables exist while editing too.

>>57217381
reminder that in C++, you could be doing the mpz version with that code

>>57217375
Well, arr is a structure you created, not a C native type

>>57217396
so are linked lists, stacks etc.

>>57217393
you can't overload operators of builtin types, no?

>>57217408
That's why I said
>Explain how you 'push' a value in a C array then faggot
>C array

>>57217231

int *push(int *array, int value)
{
    size_t n = sizeof(array) / sizeof(array[0]);
    array = realloc(array, n + 1);
    array[n] = value;
    return array[n];
}

>>57217413
>in C++
and I meant by changing "int", obviously

whats a `blob` in computer science terms?

>>57217437
nice, finally someone knows his C, although you're not testing your array after the realloc

>>57217231

#define push(a,e) *((a)++) = e
#define pop(a)    *((a)--)

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I'm attempting to export functions from my dll
what am I doing wrong /dpt/?

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>>57217437
>size_t n = sizeof(array) / sizeof(array[0]);

>>57217446
bytes

>>57217496
for what purpose?

>>57217446
basically a sequence of bytes that's used for binary storage rather than used for storing primitives

>>57217454
Is this sarcastic? Actually this function would not work if the array is dynamically allocated. Which is the case eventually.

>>57217512
storing data

>>57217446
https://en.wikipedia.org/wiki/Binary_large_object

>>57217514
bytes are primitives :^)

>>57217527
thats what I thought, bytes ARE primitives right?

>>57217527
well yes but I meant like a vague sequence rather than a well defined type

>>57210196
>meme
>meme
>meme

For my term project for a class, I want to make a parallel video game. I don't know what kind of parallel paradigm to use. Basically I'm stuck with OpenMP, MPI, or both. I could use CUDA but I don't know anything about it. There is surprisingly little information on this online. Any ideas?

>>57217512
It's just arbitrary data in a storage.

>>57217570
for what purpose

>>57217573
yes, but what are the benefits over a bit array or something similar ?

>>57217586
What else would you use to store data besides a byte array?

>>57217586
It's useful if you don't know what you are going to store. It's kinda like a custom filesystem.

>>57217323
we already established you're too dumb for this

>>57217632
>>57217586
Calling something a blob in my experience just means there's no formatting or meta data associated with it. Like, a file is just a binary blob as far as the OS is concerned. It doesn't know anything about the data besides that it's a list of bytes.

>>57217586
The reason its not called bytes is just semantics.

>>57217517
>not work if the array is dynamically allocated
it never works, you fucking moron

>>57217652
no meta data? then how is the blob referenced after you store it?
from my understanding, what most of you are describing is a buffer.

>>57217667
well, right, there might be metadata. But the blob itself does not contain the metadata. Where ever the blob is stored stores the metadata someplace.

>>57213889
the question is, why the fuck haven't they changed the/added a simpler version to API after all these years...

>>57217698
Because it's Java. Changing things for the better is not in their DNA.

>>57217688
all right then.

>>57217437
is sizeof(array) valid for arbitrary pointers? does C tag pointers somehow to implement this?
>>57217517
i think he meant checking whether realloc was successfull

>>57217811
i don't even know C
i just kinda spewed out some random code based on whatever Cfags post here
but i think that's the case similar to pointer arithmetic

>>57217788
>>57217788
>>57217788

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>>57217858

>>57213889

fout = new PrintWriter(new File("Filename.txt"))

That was hard.

>>57217911
That is fucking verbose

>>57216950
>>>/g/wdg

does dpt have a gitter room?

>>57217929
Well how would you do it?

>>57217984
writeFile str "Filename.txt"

>>57217968
I asked /dpt/ because /dpt/ is WAY smarter than /wdg/ ( or so i've heard )

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>>57217988

>>57217988
But muh streams

>>57217988
not the same thing

Not usually a /g/man, so I'm looking for advice for a three tiered counting rig. Basic design is 2 groups of 6 people with individual counter iPhones and one monitoring iPad. The counter will have 1 button for adding to the count, while the monitor will have a live count for each group and a grand total on their display. Any ideas on how to get started? I remember basic count totals from high school coding, but how would I go about linking several iPhones and an iPad wirelessly?

>>57218306
The 12 phones connect to server and upload the fact that button was pressed.
The ipad becomes the server and displays how many times individual phones had it pressed.

>>57215770
I know it was quick, but you've to click the button twice. It says "are you sure" after you click it the first time.