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  • Are there any code critique sites or similar resources?

    - by Ukko
    I have noticed when people post example code illustrating some issue that they are having often they will gather a number of comments addressing the quality of the code they presented and not the actual problem asked. This is very helpful--if not well directed. Often, this is wasted effort since the asker is often not receptive and the code is often chopped down to something small to post leaving lots of rough edges. In the old days you would see people asking questions like this on comp.lang.lisp and other parts of the comp.lang hierarchy. But that bit of the net kind of sank into the sewers of neglect. Is there a comparable one-stop-shop today? I am partially asking for selfish reasons, I know how to write good idiomatic C, Lisp, O'Caml, and Java code. But I learned C++ pre-template and STL, those rusty skills are not really applicable to today's C++. I have picked up languages like Scala in a vacuum and get by, but am I really doing it correctly? There are so many ways you can abuse a language, I am currently working against a codebase of Fortran written in C, and I recognize and loathe the "that guy" who wrote it. I don't want to be someone else's "that guy" if I can help it. Just because it works does not mean that one did not totally miss the boat on how it should have been done. Do you seek out this type of critique? If so how, where and why? What types of benefits do you derive from it? How about abuse and trolls?

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  • How is a referencing environment generally implemented for closures?

    - by Alexandr Kurilin
    Let's say I have a statically/lexically scoped language with deep binding and I create a closure. The closure will consist of the statements I want executed plus the so called referencing environment, or, to quote this post, the collection of variables which can be used. What does this referencing environment actually look like implementation-wise? I was recently reading about ObjectiveC's implementation of blocks, and the author suggests that behind the scenes you get a copy of all of the variables on the stack and also of all the references to heap objects. The explanation claims that you get a "snapshot" of the referencing environment at the point in time of the closure's creation. Is that more or less what happens, or did I misread that? Is anything done to "freeze" a separate copy of the heap objects, or is it safe to assume that if they get modified between closure creation and the closure executing, the closure will no longer be operating on the original version of the object? If indeed there's copying being made, are there memory usage considerations in situations where one might want to create plenty of closures and store them somewhere? I think that misunderstanding of some of these concepts might lead to tricky issues like the ones Eric Lippert mentions in this blog post. It's interesting because you'd think that it wouldn't make sense to keep a reference to a value type that might be gone by the time the closure is called, but I'm guessing that in C# the compiler will figure out that the variable is needed later and put it into the heap instead. It seems that in most memory-managed languages everything is a reference and thus ObjectiveC is a somewhat unique situation with having to deal with copying what's on the stack.

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  • Could I be writing this code better?

    - by Ben Dauphinee
    Is there any website out there somewhere where a programmer such as myself might be able to post pieces of code to be looked at by more experienced people? I am thinking of something that programmers could use to have advice given on how to improve their ability. I really like the atmosphere here, but am not sure that posting code for review here is appropriate.

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  • Is it possible to create a domain model for legacy code without refactoring?

    - by plaureano
    I currently have a client that wants me to 'abstract' out a domain model from the existing code but they specifically said that I shouldn't refactor the existing code itself. My question is 1) whether or not this is advisable and 2) what techniques would you apply in this scenario if you can't refactor the code yet they expect you to come up with a model for it? (EDIT: I can't quite put my finger on it, but somehow, not being able to refactor in this case just feels wrong. Has anyone else run into this type of scenario?)

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  • Other ternary operators besides ternary conditional (?:)

    - by Malcolm
    The "ternary operator" expression is now almost equivalent to the ternary conditional operator: condition ? trueExpression : falseExpression; However, "ternary operator" only means that it takes three arguments. I'm just curious, are there any languages with any other built-in ternary operators besides conditional operator and which ones?

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  • Bluetooth service problem

    - by hara
    hi I need to create a custom bluetooth service and I have to develop it using c++. I read a lot of examples but I didn't success in publishing a new service with a custom UUID. I need to specify a UUID in order to be able to connect to the service from an android app. This is what i wrote: GUID service_UUID = { /* 00000003-0000-1000-8000-00805F9B34FB */ 0x00000003, 0x0000, 0x1000, {0x80, 0x00, 0x00, 0x80, 0x5F, 0x9B, 0x34, 0xFB} }; SOCKET s, s2; SOCKADDR_BTH sab if (WSAStartup(MAKEWORD(2, 2), &wsd) != 0) return 1; printf("installing a new service\n"); s = socket(AF_BTH, SOCK_STREAM, BTHPROTO_RFCOMM); if (s == INVALID_SOCKET) { printf ("Socket creation failed, error %d\n", WSAGetLastError()); return 1; } memset (&sab, 0, sizeof(sab)); sab.addressFamily = AF_BTH; sab.port = BT_PORT_ANY; sab.serviceClassId = service_UUID; if (0 != bind(s, (SOCKADDR *) &sab, sizeof(sab))) { printf ("bind() failed with error code %d\n", WSAGetLastError()); closesocket (s); return 1; } int result=sizeof(sab); getsockname(s,(SOCKADDR *) &sab, &result ); printSOCKADDR_BTH(sab); if(listen (s, 5) == 0) printf("listen() is OK! Listening for connection... :)\n"); else printf("listen() failed with error code %d\n", WSAGetLastError()); printf("waiting connection"); for ( ; ; ) { int ilen = sizeof(sab2); s2 = accept (s, (SOCKADDR *)&sab2, &ilen); printf ("accepted"); } if(closesocket(s) == 0) printf("closesocket() pretty fine!\n"); if(WSACleanup () == 0) printf("WSACleanup() is OK!\n"); return 0; When i print the SOCKADDR_BTH structure retrieved with get getsockname i get an UUID that is not the mine. Furthermore if i use the UUID read from getsockname to connect the Android application the connection fails with this exception: java.io.IOException: Service discovery failed Could you help me?? Thanks!

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  • Visual Studio 2010 Language Support

    - by inspectorG4dget
    Hello SO, I want to be able to develop code using Visual Studio 2010. I just got VS2010 and I'm not able to get the languages I want on it. The main reason that I'm asking this is that I'm trying to migrate to ONE IDE that does it all for me. Thus far eclipse has been doing a good job, but I've been informed that VS2010 is better and I'm trying to get into the groove of that standard So my question is two-fold. I am not able to find a complete list of languages supported by VS2010. What are these languages? How can I get VS2010 support for: a. Python/IronPython b. C/C++/C#/XNA c. Java My Googling has given me no promising/definitive results. I'd really appreciate any help.

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  • Recommended way to support backward/forward compatibility in iPhone app?

    - by MrAleGuy
    I'm in the early stages of an iPhone app and I have a question. I did some searching but did not find what I was looking for. There are features in iPhone OS4 that I would like to take advantage of, but I would like for my app to also run on 3.X. It looks like I want to develop against the 4.0 SDK and do the following: Create a "weak link" to any new (4.0) frameworks Call respondsToSelector: for any new method in an existing framework or any method in a new framework before making that call Am I close? What's recommended? Pointers to similar questions welcome.

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  • what do you do while code is compiling

    - by Jacob
    I'm looking for the best idea for what to do while code is compiling or tests are running. Typically around 5 minutes of thumb twiddling. Only so many cups of coffee can be made and drunk in a day, and I don't want to be seen always in the kitchen or bothering other people.

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  • Finding Local IP via Socket Creation / getsockname

    - by BSchlinker
    I need to get the IP address of a system within C++. I followed the logic and advice of another comment on here and created a socket and then utilized getsockname to determine the IP address which the socket is bound to. However, this doesn't appear to work (code below). I'm receiving an invalid IP address (58.etc) when I should be receiving a 128.etc Any ideas? string Routes::systemIP(){ // basic setup int sockfd; char str[INET_ADDRSTRLEN]; sockaddr* sa; socklen_t* sl; struct addrinfo hints, *servinfo, *p; int rv; memset(&hints, 0, sizeof hints); hints.ai_family = AF_UNSPEC; hints.ai_socktype = SOCK_DGRAM; if ((rv = getaddrinfo("4.2.2.1", "80", &hints, &servinfo)) != 0) { fprintf(stderr, "getaddrinfo: %s\n", gai_strerror(rv)); return "1"; } // loop through all the results and make a socket for(p = servinfo; p != NULL; p = p->ai_next) { if ((sockfd = socket(p->ai_family, p->ai_socktype, p->ai_protocol)) == -1) { perror("talker: socket"); continue; } break; } if (p == NULL) { fprintf(stderr, "talker: failed to bind socket\n"); return "2"; } // get information on the local IP from the socket we created getsockname(sockfd, sa, sl); // convert the sockaddr to a sockaddr_in via casting struct sockaddr_in *sa_ipv4 = (struct sockaddr_in *)sa; // get the IP from the sockaddr_in and print it inet_ntop(AF_INET, &(sa_ipv4->sin_addr.s_addr), str, INET_ADDRSTRLEN); printf("%s\n", str); // return the IP return str; }

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  • Did Java invent interfaces?

    - by Jordão
    I know about C++ pure virtual classes, but Java went one step further and created a first-class (no pun intended) concept for multiple-interface (not implementation) inheritance, the interface. It's now a staple of major statically-typed languages. Did Java invent the interface concept? Or did it appear in older languages also as a first-class concept?

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  • Any merit to a lazy-ish juxt function?

    - by NielsK
    In answering a question about a function that maps over multiple functions with the same arguments (A: juxt), I came up with a function that basically took the same form as juxt, but used map: (defn could-be-lazy-juxt [& funs] (fn [& args] (map #(apply %1 %2) funs (repeat args)))) => ((juxt inc dec str) 1) [2 0 "1"] => ((could-be-lazy-juxt inc dec str) 1) (2 0 "1") => ((juxt * / -) 6 2) [12 3 4] => ((could-be-lazy-juxt * / -) 6 2) (12 3 4) As posted in the original question, I have little clue about the laziness or performance of it, but timing in the REPL does suggest something lazy-ish is going on. => (time (apply (juxt + -) (range 1 100))) "Elapsed time: 0.097198 msecs" [4950 -4948] => (time (apply (could-be-lazy-juxt + -) (range 1 100))) "Elapsed time: 0.074558 msecs" (4950 -4948) => (time (apply (juxt + -) (range 10000000))) "Elapsed time: 1019.317913 msecs" [49999995000000 -49999995000000] => (time (apply (could-be-lazy-juxt + -) (range 10000000))) "Elapsed time: 0.070332 msecs" (49999995000000 -49999995000000) I'm sure this function is not really that quick (the print of the outcome 'feels' about as long in both). Doing a 'take x' on the function only limits the amount of functions evaluated, which probably is limited in it's applicability, and limiting the other parameters by 'take' should be just as lazy in normal juxt. Is this juxt really lazy ? Would a lazy juxt bring anything useful to the table, for instance as a compositing step between other lazy functions ? What are the performance (mem / cpu / object count / compilation) implications ? Is that why the Clojure juxt implementation is done with a reduce and returns a vector ? Edit: Somehow things can always be done simpler in Clojure. (defn could-be-lazy-juxt [& funs] (fn [& args] (map #(apply % args) funs)))

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  • Enumerating computers in NT4 domain using WNetEnumResourceW (C++) or DirectoryEntry (C#)

    - by Kevin Davis
    I'm trying to enumerate computers in NT4 domains (not Active Directory) and support Unicode NetBIOS names. According to MSDN, WNetEnumResourceW is the Unicode counterpart of WNetEnumResource which to me would imply that using this would do the trick. However, I have not been able to get Unicode NetBIOS names properly using WNetEnumResourceW. I've also tried the C# rough equivalent DirectoryEntry using the WinNT: provider with no luck on Unicode names either. If I use DirectoryEntry on Active Directory (using the LDAP: provider) I do get Unicode names back. I noticed that during some debugging my code using DirectoryEntry and the WinNT: provider, the exceptions I saw were of type System.Runtime.InteropServices.COMException which tends to make me believe that this is just calling WNetEnumResourceW via COM. This web page implies that for some Net APIs the MS documentation is incomplete and possibly inaccurate which further confuses things. Additionally I've found that using the C# method which certainly results in cleaner, more understandable code also yields incomplete results in enumerating computers in domains\workgroups. Does anyone have any insight on this? Is it possible that computer acting as the WINS server is mangling the name? How would I determine this? Thanks

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  • Writing a VM - well formed bytecode?

    - by David Titarenco
    Hi, I'm writing a virtual machine in C just for fun. Lame, I know, but luckily I'm on SO so hopefully no one will make fun :) I wrote a really quick'n'dirty VM that reads lines of (my own) ASM and does stuff. Right now, I only have 3 instructions: add, jmp, end. All is well and it's actually pretty cool being able to feed lines (doing it something like write_line(&prog[1], "jmp", regA, regB, 0); and then running the program: while (machine.code_pointer <= BOUNDS && DONE != true) { run_line(&prog[machine.cp]); } I'm using an opcode lookup table (which may not be efficient but it's elegant) in C and everything seems to be working OK. My question is more of a "best practices" question but I do think there's a correct answer to it. I'm making the VM able to read binary files (storing bytes in unsigned char[]) and execute bytecode. My question is: is it the VM's job to make sure the bytecode is well formed or is it just the compiler's job to make sure the binary file it spits out is well formed? I only ask this because what would happen if someone would edit a binary file and screw stuff up (delete arbitrary parts of it, etc). Clearly, the program would be buggy and probably not functional. Is this even the VM's problem? I'm sure that people much smarter than me have figured out solutions to these problems, I'm just curious what they are!

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  • What "exotic" language feature do you use every day?

    - by fmark
    For most programmers using procedural or object-oriented languages there is a language-feature lowest common denominator: variables, procedures, standard control structures, and classes. However, almost all languages add features on top of this. Recent C# versions have LINQ and delegates. C++ has template metaprogramming. Java has annotations. What features such as these do you use every day?

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  • reassembling http packets with perl and parsing it

    - by johnny2
    I am using net::pcap module to capture packets with this filter: dst $my_host and dst port 80 inside the net::pcap::loop i use the below callback function: net::pcap::loop($pcap_t,-1,\my_callback,'') where my_callback look like this : my_callback { my ($user_data, $header, $packet) = @_; # Strip ethernet IP and TCP my $ether_data = NetPacket::Ethernet::strip($packet); my $ip = NetPacket::IP->decode($ether_data); my $tcp = NetPacket::TCP->decode($ip->{'data'}); } could someone help me how can i assemble the http packets to one packet and extract its header .

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  • Why do some languages not use semicolons and braces?

    - by Incognito
    It is interesting that some languages do not use semicolons and braces, even though their predecessors had them. Personally, it makes me nervous to write code in Python because of this. Semicolons are also missing from Google's GO language, although the lexer uses a rule to insert semicolons automatically as it scans. Why do some languages not use semicolons and braces?

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  • assembly of pdp-11(simulator)

    - by lego69
    I have this code on pdp-11 tks = 177560 tkb = 177562 tps = 177564 tpb = 177566 lcs = 177546 . = torg + 2000 main: mov #main, sp mov #kb_int, @#60 mov #200, @#62 mov #101, @#tks mov #clock, @#100 mov #300, @#102 mov #100, @#lcs loop: mov @#tks,r2 aslb r2 bmi loop halt clock: tst bufferg beq clk_end mov #msg,-(sp) jsr pc, print_str tst (sp)+ clr bufferg bic #100,@#tks clr @#lcs clk_end:rti kb_int: mov r1,-(sp) jsr pc, read_char movb r1,@buff_ptr inc buff_ptr bis #1,@#tks cmpb r1,#'q bne next_if mov #0, @#tks next_if:cmpb r1,#32. bne end_kb_int clrb @buff_ptr mov #buffer,-(sp) jsr pc, print_str tst (sp)+ mov #buffer,buff_ptr end_kb_int: mov (sp)+,r1 rti ;############################# read_char: tstb @#tks bpl read_char movb @#tkb, r1 rts pc ;############################# print_char: tstb @#tps bpl print_char movb r1, @#tpb rts pc ;############################# print_str: mov r1,-(sp) mov r2,-(sp) mov 6(sp),r2 str_loop: movb (r2)+,r1 beq pr_str_end jsr pc, print_char br str_loop pr_str_end: mov (sp)+,r2 mov (sp)+,r1 rts pc . = torg + 3000 msg:.ascii<Something is wrong!> .byte 0 .even buff_ptr: .word buffer buffer: .blkw 3 bufferg: .word 0 Can somebody please explain how this part is working, thanks in advance movb r1,@buff_ptr inc buff_ptr bis #1,@#tks cmpb r1,#'q bne next_if mov #0, @#tks next_if:cmpb r1,#32. bne end_kb_int clrb @buff_ptr mov #buffer,-(sp) jsr pc, print_str tst (sp)+ mov #buffer,buff_ptr

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  • Too many open connections... Did I mess up something?

    - by Legend
    I am developing a plugin (for a Bittorrent client named Azureus programmed in Java) that lets me add peers into the current list from which it is downloading. Everything was working fine until yesterday when I started getting these weird errors: DEBUG::Thu Apr 15 10:45:40 CET 2010::org.gudy.azureus2.core3.peer.impl.control.PEPeerControlImpl::addPeer::795: Injected peer 90.35.126.126:33064 was not added - Too many connections DEBUG::Thu Apr 15 10:48:40 CET 2010::org.gudy.azureus2.core3.peer.impl.control.PEPeerControlImpl::addPeer::795: Injected peer 80.25.126.126:33064 was not added - Too many connections DEBUG::Thu Apr 15 10:52:40 CET 2010::org.gudy.azureus2.core3.peer.impl.control.PEPeerControlImpl::addPeer::795: Injected peer 90.35.126.126:33064 was not added - Too many connections I am thinking I messed up something with the TCP sockets. Does anyone know why this could be happening?

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