Search Results

Search found 10698 results on 428 pages for 'inline functions'.

Page 111/428 | < Previous Page | 107 108 109 110 111 112 113 114 115 116 117 118  | Next Page >

  • I am looking to create realistic car movement using vectors

    - by bobthemac
    I have goggled how to do this and found this http://www.helixsoft.nl/articles/circle/sincos.htm I have had a go at it but most of the functions that were showed didn't work I just got errors because they didn't exist. I have looked at the cos and sin functions but don't understand how to use them or how to get the car movement working correctly using vectors. I have no code because I am not sure what to do sorry. Any help is appreciated. EDIT: I have restrictions that I must use the TL engine for my game, I am not allowed to add any sort of physics engine. It must be programmed in c++. Here is a sample of what i got from trying to follow what was done in the link I provided. if(myEngine->KeyHeld(Key_W)) { length += carSpeedIncrement; } if(myEngine->KeyHeld(Key_S)) { length -= carSpeedIncrement; } if(myEngine->KeyHeld(Key_A)) { angle -= carSpeedIncrement; } if(myEngine->KeyHeld(Key_D)) { angle += carSpeedIncrement; } carVolocityX = cos(angle); carVolocityZ = cos(angle); car->MoveX(carVolocityX * frameTime); car->MoveZ(carVolocityZ * frameTime);

    Read the article

  • Pathfinding with MicroPather : costs calculations with sectors and portals

    - by Adan
    Hello, I'm considering using micropather to help me with pathfinding. I'm not using a discrete map : I'm working in 2d with sectors and portales. However, I'm just wondering what is the best way to compute costs with this library in this context. Just to be more clear about geometrical shapes I'm using : sectors are basically convex polygons, and portals are segments that lies on sector's edge. Micropather exposes a pure virtual Graph class that you must inherate and overrides 3 functions. I understand how pathfinding works, so there's no problem in overriding those functions. Right now, my implementation give me results, i.e I'm able to find a path in my map, but I'm not sure I'm using an optimal solution. For the AdjacentCost method : I just take the distance between sector's centers as the cost. I think a better solution should be to use the portal between the two sectors, compute its center, and then the cost should be : distance( sector A center, portal center ) + distance ( sector B center, portal center ). I'm pretty sure the approximation I'm using with just sector's center is enough for most cases, but maybe with thin and long sectors that are perpendicular, this approximation could mislead the A* algorithm. For the LeastCostEstimate method : I just take the midpoint of the two sectors. So, as you understand, I'm always working with sectors' centers, and it's working fine. And I'm pretty sure there's a better way to work. Any suggestions or feedbacks? Thanks in advance!

    Read the article

  • Parse text file on click - and then display

    - by John R
    I am thinking of a methodology for rapid retrieval of code snippets. I imagine an HTML table with a setup like this: one two ... ten one oneTwo() oneTen() two twoOne() twoTen() ... ten tenOne() tenTwo() When a user clicks a function in this HTML table, a snippet of code is shown in another div tag or perhaps a popup window (I'm open to different solutions). I want to maintain only one PHP file named utitlities.php that contains a class called 'util'. This file & class will hold all the functions referenced in the above table (it is also used on various projects and is functional code). A key idea is that I do not want to update the HTML documentation everytime I write/update a new function in utilities.php. I should be able to click a function in the table and have PHP open the utilities file, parse out the apropriate function and display it in an HTML window. Questions: 1) I will be coding this in PHP and JavaScript but am wondering if similar scripts are available (for all or part) so I don't reinvent the wheel. 2) Quick & easy Ajax suggestions appreciated too (probably will use jquery, but am rusty). 3) Methodology for parsing out the functions from the utilities.php file (I'm not to good with regex).

    Read the article

  • Parse text file on click and display

    - by John R
    I am thinking of a methodology for rapid retrieval of code snippets. I imagine an HTML table with a setup like this: one two ... ten one oneTwo() oneTen() two twoOne() twoTen() ... ten tenOne() tenTwo() When a user clicks a function in this HTML table, a snippet of code is shown in another div tag or perhaps a popup window (I'm open to different solutions). I want to maintain only one PHP file named utitlities.php that contains a class called 'util'. This file & class will hold all the functions referenced in the above table (it is also used on various projects and is functional code). A key idea is that I do not want to update the HTML documentation everytime I write/update a new function in utilities.php. I should be able to click a function in the table and have PHP open the utilities file, parse out the apropriate function and display it in an HTML window. Questions: 1) I will be coding this in PHP and JavaScript but am wondering if similar scripts are available (for all or part) so I don't reinvent the wheel. 2) Quick & easy Ajax suggestions appreciated too (probably will use jquery, but am rusty). 3) Methodology for parsing out the functions from the utilities.php file (I'm not to good with regex).

    Read the article

  • How do I use an API?

    - by GRardB
    Background I have no idea how to use an API. I know that all APIs are different, but I've been doing research and I don't fully understand the documentation that comes along with them. There's a programming competition at my university in a month and a half that I want to compete in (revolved around APIs) but nobody on my team has ever used one. We're computer science majors, so we have experience programming, but we've just never been exposed to an API. I tried looking at Twitter's documentation, but I'm lost. Would anyone be able to give me some tips on how to get started? Maybe a very easy API with examples, or explaining essential things about common elements of different APIs? I don't need a full-blown tutorial on Stack Overflow; I just need to be pointed in the right direction. Update The programming languages that I'm most fluent in are C (simple text editor usually) and Java (Eclipse). In an attempt to be more specific with my question: I understand that APIs (and yes, external libraries are what I was referring to) are simply sets of functions. Question I guess what I'm trying to ask is how I would go about accessing those functions. Do I need to download specific files and include them in my programs, or do they need to be accessed remotely, etc.?

    Read the article

  • Code execution time out occationally

    - by Athul k Surendran
    I am working on an e-commerce website. There is a case where I need to fetch the whole data in database through third-party API and send it to an indexing engine. This third-party API has many functions like getproducts, getproductprice, etc., and each of that functions will return the data in XML format. From there I will take charge, I will use various API calls and will handle the XML data with XSLT. And will write to a CSV file. This file will be uploaded to an Indexing engine. Right now I have details of 8000 products to feed the engine, and almost all time the this process takes about 15 min to complete, and sometimes fails. I can't find a better solution for this. I am thinking about handling the XML data in C# itself and get rid of XSLT. As I think, XSLT is far slower than C#. Is it a good Idea? Or what else I can do to solve this issue?

    Read the article

  • How do I use an API?

    - by GRardB
    Background I have no idea how to use an API. I know that all APIs are different, but I've been doing research and I don't fully understand the documentation that comes along with them. There's a programming competition at my university in a month and a half that I want to compete in (revolved around APIs) but nobody on my team has ever used one. We're computer science majors, so we have experience programming, but we've just never been exposed to an API. I tried looking at Twitter's documentation, but I'm lost. Would anyone be able to give me some tips on how to get started? Maybe a very easy API with examples, or explaining essential things about common elements of different APIs? I don't need a full-blown tutorial on Stack Overflow; I just need to be pointed in the right direction. Update The programming languages that I'm most fluent in are C (simple text editor usually) and Java (Eclipse). In an attempt to be more specific with my question: I understand that APIs (and yes, external libraries are what I was referring to) are simply sets of functions. Question I guess what I'm trying to ask is how I would go about accessing those functions. Do I need to download specific files and include them in my programs, or do they need to be accessed remotely, etc.?

    Read the article

  • Prefer class members or passing arguments between internal methods?

    - by geoffjentry
    Suppose within the private portion of a class there is a value which is utilized by multiple private methods. Do people prefer having this defined as a member variable for the class or passing it as an argument to each of the methods - and why? On one hand I could see an argument to be made that reducing state (ie member variables) in a class is generally a good thing, although if the same value is being repeatedly used throughout a class' methods it seems like that would be an ideal candidate for representation as state for the class to make the code visibly cleaner if nothing else. Edit: To clarify some of the comments/questions that were raised, I'm not talking about constants and this isn't relating to any particular case rather just a hypothetical that I was talking to some other people about. Ignoring the OOP angle for a moment, the particular use case that I had in mind was the following (assume pass by reference just to make the pseudocode cleaner) int x doSomething(x) doAnotherThing(x) doYetAnotherThing(x) doSomethingElse(x) So what I mean is that there's some variable that is common between multiple functions - in the case I had in mind it was due to chaining of smaller functions. In an OOP system, if these were all methods of a class (say due to refactoring via extracting methods from a large method), that variable could be passed around them all or it could be a class member.

    Read the article

  • Is there a name for the Builder Pattern where the Builder is implemented via interfaces so certain parameters are required?

    - by Zipper
    So we implemented the builder pattern for most of our domain to help in understandability of what actually being passed to a constructor, and for the normal advantages that a builder gives. The one twist was that we exposed the builder through interfaces so we could chain required functions and unrequired functions to make sure that the correct parameters were passed. I was curious if there was an existing pattern like this. Example below: public class Foo { private int someThing; private int someThing2; private DateTime someThing3; private Foo(Builder builder) { this.someThing = builder.someThing; this.someThing2 = builder.someThing2; this.someThing3 = builder.someThing3; } public static RequiredSomething getBuilder() { return new Builder(); } public interface RequiredSomething { public RequiredDateTime withSomething (int value); } public interface RequiredDateTime { public OptionalParamters withDateTime (DateTime value); } public interface OptionalParamters { public OptionalParamters withSeomthing2 (int value); public Foo Build ();} public static class Builder implements RequiredSomething, RequiredDateTime, OptionalParamters { private int someThing; private int someThing2; private DateTime someThing3; public RequiredDateTime withSomething (int value) {someThing = value; return this;} public OptionalParamters withDateTime (int value) {someThing = value; return this;} public OptionalParamters withSeomthing2 (int value) {someThing = value; return this;} public Foo build(){return new Foo(this);} } } Example of how it's called: Foo foo = Foo.getBuilder().withSomething(1).withDateTime(DateTime.now()).build(); Foo foo2 = Foo.getBuilder().withSomething(1).withDateTime(DateTime.now()).withSomething2(3).build();

    Read the article

  • Is it okay to showcase templates/layouts recreated in different codes in a portfolio?

    - by Souta
    I have several different templates/layouts, both simple and complex. I recreated these templates multiple times, just using different codes. (Say, a complex one was originally made in only HTML and CSS, I recreated it using HTML, Javascript, CSS, then again with a HTML and PHP concoction, and etc.) I wanted to showcase my work and skills by doing this, but I don't know if it would be okay for that all to go into a resumé/portfolio. This is why: Freelancing Does potential business really care about how their site is made, as long as it looks and functions to their liking? (As in, should I just only show the one example of each template/layout and not the multiple recreations?) Potential Hire However, if a potential employer were to stumble across my resumé/portfolio, would having the multiple recreations do any good for a career outlook? (As in, this potential employer is a company where I could be working on a team to create/develop sites and not be freelancing; would a lack of skill-shining turn this employer away because I didn't set myself apart and show that I'm not just like every other budding web designer?) Those two issues have me wondering if it is okay to have a resumé/portfolio combined for this specific reason. Or does something like this not matter to potential business (as a freelancer) because they wouldn't care either way as long as it looks and functions to their liking and therefore it is okay to showcase the recreations with the originals?

    Read the article

  • Is there a (family of) monotonically non-decreasing noise function(s)?

    - by Joe Wreschnig
    I'd like a function to animate an object moving from point A to point B over time, such that it reaches B at some fixed time, but its position at any time is randomly perturbed in a continuous fashion, but never goes backwards. The objects move along straight lines, so I only need one dimension. Mathematically, that means I'm looking for some continuous f(x), x ? [0,1], such that: f(0) = 0 f(1) = 1 x < y ? f(x) = f(y) At "most" points f(x + d) - f(x) bears no obvious relation to d. (The function is not uniformly increasing or otherwise predictable; I think that's also equivalent to saying no degree of derivative is a constant.) Ideally, I would actually like some way to have a family of these functions, providing some seed state. I'd need at least 4 bits of seed (16 possible functions), for my current use, but since that's not much feel free to provide even more. To avoid various issues with accumulation errors, I'd prefer the function not require any kind of internal state. That is, I want it to be a real function, not a programming "function".

    Read the article

  • OpenGL Application displays only 1 frame

    - by Avi
    EDIT: I have verified that the problem is not the VBO class or the vertex array class, but rather something else. I have a problem where my vertex buffer class works the first time its called, but displays nothing any other time its called. I don't know why this is, and it's also the same in my vertex array class. I'm calling the functions in this order to set up the buffers: enable client states bind buffers set buffer / array data unbind buffers disable client states Then in the draw function, that's called every frame: enable client states bind buffers set pointers unbind buffers bind index buffer draw elements unbind index buffer disable client states Is there something wrong with the order in which I'm calling the functions, or is it a more specific code error? EDIT: here's some of the code Code for setting pointers: //element is the vertex attribute being drawn (e.g. normals, colors, etc.) static void makeElementPointer(VertexBufferElements::VBOElement element, Shader *shade, void *elementLocation) { //elementLocation is BUFFER_OFFSET(n) if a buffer is bound switch (element) { .... glVertexPointer(3, GL_FLOAT, 0, elementLocation); //changes based on element .... //but I'm only dealing with } //vertices for now } And that's basically all the code that isn't just a straight OpenGL function call.

    Read the article

  • Create an array from mysql with column names and values [on hold]

    - by ScaZ
    i'm trying to create an array with PHP and MySQL, but i always get errors. The code i'm using function db_listar_usuarios(){ $link=db_connect(); $query = "select * from usuarios" or die("Problemas en el select: " . mysqli_error($link)); $result = $link->query($query); while($row = mysqli_fetch_assoc($result)) { $row['nombre'] . array(; foreach ($row as $col => $val) { $col => $val; } } } And what I want to create with this code is: array( 'john' => array('address' => 'st 123', 'age' => '25', 'surname' => 'doe'), 'ane' => array('address' => 'av 456', 'age'=> '32', 'surname' => 'smith'), ); To use then like something like this: private $contacts = db_listar_usuarios(); I use 2 files: functions.php and server.php server.php is a downloaded file example to do a REST API. Here are both of them. server.php - pastebin.com/5j54m1Mz functions.php - pastebin.com/N7jMhSBa Thank you in advance!

    Read the article

  • Gave a talk at SoCal Code Camp at USC today titled “Linq to Objects A-Z”

    - by dotneteer
    I gave a talk at SoCal Code Camp on Linq to Objects. With careful categorization of Linq functions, I was able to cover the entire set of Linq functions in only 35 minutes. I was able to spend the rest time on demos. In my first demo, I show I was able to write a top 20 URL type of query using 4 lines of library code and 9 line of Linq code without tools like Log Parser. I also demonstrated that I only need to change 2 lines of code from querying a single log file to a whole directory of log files. It would be as simple to run the query against multiple servers in parallel. In my second demo, I discussed how to turn into graph depth-first-search (DFS) and breath-first-search (BFS) in the a Linq queryable problem. The class LingToGraph contains the only DFS and BFS code I ever have to write; the rest could be done the the lambda passed to the DFS or BFS calls. In future blogs, I will provide more details explanation of code. Links: Link to Powerpoint slides. Link to demos.

    Read the article

  • FP for simulation and modelling

    - by heaptobesquare
    I'm about to start a simulation/modelling project. I already know that OOP is used for this kind of projects. However, studying Haskell made me consider using the FP paradigm for modelling a system of components. Let me elaborate: Let's say I have a component of type A, characterised by a set of data (a parameter like temperature or pressure,a PDE and some boundary conditions,etc.) and a component of type B, characterised by a different set of data(different or same parameter, different PDE and boundary conditions). Let's also assume that the functions/methods that are going to be applied on each component are the same (a Galerkin method for example). If I were to use an OOP approach, I would create two objects that would encapsulate each type's data, the methods for solving the PDE(inheritance would be used here for code reuse) and the solution to the PDE. On the other hand, if I were to use an FP approach, each component would be broken down to data parts and the functions that would act upon the data in order to get the solution for the PDE. This approach seems simpler to me assuming that linear operations on data would be trivial and that the parameters are constant. What if the parameters are not constant(for example, temperature increases suddenly and therefore cannot be immutable)? In OOP, the object's (mutable) state can be used. I know that Haskell has Monads for that. To conclude, would implementing the FP approach be actually simpler,less time consuming and easier to manage (add a different type of component or new method to solve the pde) compared to the OOP one? I come from a C++/Fortran background, plus I'm not a professional programmer, so correct me on anything that I've got wrong.

    Read the article

  • Using C++ but not using the language's specific features, should switch to C?

    - by Petruza
    I'm developing a NES emulator as a hobby, in my free time. I use C++ because is the language I use mostly, know mostly and like mostly. But now that I made some advance into the project I realize I'm not using almost any specific features of C++, and could have done it in plain C and getting the same result. I don't use templates, operator overloading, polymorphism, inheritance. So what would you say? should I stay in C++ or rewrite it in C? I won't do this to gain in performance, it could come as a side effect, but the idea is why should I use C++ if I don't need it? The only features of C++ I'm using is classes to encapsulate data and methods, but that can be done as well with structs and functions, I'm using new and delete, but could as well use malloc and free, and I'm using inheritance just for callbacks, which could be achieved with pointers to functions. Remember, it's a hobby project, I have no deadlines, so the overhead time and work that would require a re-write are not a problem, might be fun as well. So, the question is C or C++?

    Read the article

  • Is the Entity Component System architecture object oriented by definition?

    - by tieTYT
    Is the Entity Component System architecture object oriented, by definition? It seems more procedural or functional to me. My opinion is that it doesn't prevent you from implementing it in an OO language, but it would not be idiomatic to do so in a staunchly OO way. It seems like ECS separates data (E & C) from behavior (S). As evidence: The idea is to have no game methods embedded in the entity. And: The component consists of a minimal set of data needed for a specific purpose Systems are single purpose functions that take a set of entities which have a specific component I think this is not object oriented because a big part of being object oriented is combining your data and behavior together. As evidence: In contrast, the object-oriented approach encourages the programmer to place data where it is not directly accessible by the rest of the program. Instead, the data is accessed by calling specially written functions, commonly called methods, which are bundled in with the data. ECS, on the other hand, seems to be all about separating your data from your behavior.

    Read the article

  • @staticmethod vs module-level function

    - by darkfeline
    This is not about @staticmethod and @classmethod! I know how staticmethod works. What I want to know is the proper use cases for @staticmethod vs. a module-level function. I've googled this question, and it seems there's some general agreement that module-level functions are preferred over static methods because it's more pythonic. Static methods have the advantage of being bound to its class, which may make sense if only that class uses it. However, in Python functionality is usually organized by module not class, so usually making it a module function makes sense too. Static methods can also be overridden by subclasses, which is an advantage or disadvantage depending on how you look at it. Although, static methods are usually "functionally pure" so overriding it may not be smart, but it may be convenient sometimes (though this may be one of those "convenient, but NEVER DO IT" kind of things only experience can teach you). Are there any general rule-of-thumbs for using either staticmethod or module-level functions? What concrete advantages or disadvantages do they have (e.g. future extension, external extension, readability)? If possible, also provide a case example.

    Read the article

  • When decomposing a large function, how can I avoid the complexity from the extra subfunctions?

    - by missingno
    Say I have a large function like the following: function do_lots_of_stuff(){ { //subpart 1 ... } ... { //subpart N ... } } a common pattern is to decompose it into subfunctions function do_lots_of_stuff(){ subpart_1(...) subpart_2(...) ... subpart_N(...) } I usually find that decomposition has two main advantages: The decomposed function becomes much smaller. This can help people read it without getting lost in the details. Parameters have to be explicitly passed to the underlying subfunctions, instead of being implicitly available by just being in scope. This can help readability and modularity in some situations. However, I also find that decomposition has some disadvantages: There are no guarantees that the subfunctions "belong" to do_lots_of_stuff so there is nothing stopping someone from accidentally calling them from a wrong place. A module's complexity grows quadratically with the number of functions we add to it. (There are more possible ways for things to call each other) Therefore: Are there useful convention or coding styles that help me balance the pros and cons of function decomposition or should I just use an editor with code folding and call it a day? EDIT: This problem also applies to functional code (although in a less pressing manner). For example, in a functional setting we would have the subparts be returning values that are combined in the end and the decomposition problem of having lots of subfunctions being able to use each other is still present. We can't always assume that the problem domain will be able to be modeled on just some small simple types with just a few highly orthogonal functions. There will always be complicated algorithms or long lists of business rules that we still want to correctly be able to deal with. function do_lots_of_stuff(){ p1 = subpart_1() p2 = subpart_2() pN = subpart_N() return assembleStuff(p1, p2, ..., pN) }

    Read the article

  • multi-thread in mmorpg server

    - by jean
    For MMORPG, there is a tick function to update every object's state in a map. The function was triggered by a timer in fixed interval. So each map's update can be dispatch to different thread. At other side, server handle player incoming package have its own threads also: I/O threads. Generally, the handler of the corresponding incoming package run in I/O threads. So there is a problem: thread synchronization. I have consider two methods: Synchronize with mutex. I/O thread lock a mutex before execute handler function and map thread lock same mutex before it execute map's update. Execute all handler functions in map's thread, I/O thread only queue the incoming handler and let map thread to pop the queue then call handler function. These two have a disadvantage: delay. For method 1, if the map's tick function is running, then all clients' request need to waiting the lock release. For method 2, if map's tick function is running, all clients' request need to waiting for next tick to be handle. Of course, there is another method: add lock to functions that use data which will be accessed both in I/O thread & map thread. But this is hard to maintain and easy to goes incorrect. It needs carefully check all variables whether or not accessed by both two kinds thread. My problem is: is there better way to do this? Notice that I said map is logic concept means no interactions can happen between two map except transport. I/O thread means thread in 3rd part network lib which used to handle client request.

    Read the article

  • Is there an alternative to the term "calling object"?

    - by ybakos
    Let's suppose you've got a class defined (in pseudocode): class Puppy { // ... string sound = "Rawr!"; void bark() { print(sound); } } And say, given a Puppy instance, you call it's bark() method: Puppy p; p.bark(); Notice how bark() uses the member variable sound. In many contexts, I've seen folks describe sound as the member variable of the "calling object." My question is, what's a better term to use than "calling object?" To me, the object is not doing any calling. We know that member functions are in a way just functions with an implicit this or self parameter. I've come up with "receiving object," or "message recipient," which makes sense if you're down with the "messaging" paradigm. Do any of you happy hackers have a term that you like to use? I feel it should mean "the object upon which a method is called" and TOUWAMIC just doesn't cut it.

    Read the article

  • Value my C++ knowledge

    - by PirateOwh
    I have only followed antiRTFM tutorials and read 2 books So, I'll list the things I know better : basic input output and all the variables : integers ( signed unsigned ), float, double, char arrays if, for, while, switch functions, and passing variables to functions and return type thing classes and the concept of oop with separating declaration and definition in the header and in the source pointers so this and some more i think is all i know of C++.. But, i need some exercises to test my knowledge because i want to move on to the library SDL, so I don't know if i should feel ready or not to move on to something totally different.. I feel I should know the basics for good at least. So the question is : How can i value my c++ knowledge? Is there any online tests? Is there any GDD ( Game Design Document ) for free to use and see if i can manage to do it so "i'd pass" ? ( I'm saying GDD since ill move on to SDL and try to make my own game ) When should I move to SDL? What are ALL the things I should "master" ( master is a big word to say.. but so you understand what i mean ) before moving on ? Please I'm really in need of expert advice. I think my question is detailed so i hope you understand what i mean and can give me a good reply. Thanks for the help!

    Read the article

  • Best setup/workflow for distributed team to integrated DSVC with fragmented huge .NET site?

    - by lazfish
    So we have a team with 2 developers one manager. The dev server sits in a home office and the live server sits in a rack somewhere handled by the larger part of my company. We have freedom to do as we please but I want to incorporate Kiln DSVC and FogBugz for us with some standard procedures to make sense of our decisions/designs/goals. Our main product is web-based training through our .NET site with many videos etc, and we also do mobile apps for multiple platforms. Our code-base is a 15 yr old fragmented mess. The approach has been rogue .asp/.aspx pages with some class management implemented in the last 6 years. We still mix our html/vb/js all on the same file when we add a feature/page to our site. We do not separate the business logic from the rest of the code. Wiring anything up in VS for Intelli-sense or testing or any other benefit is more frustrating than it is worth, because of having to manually rejigger everything back to one file. How do other teams approach this? I noticed when I did wire everything up for VS it wants to make a class for all functions. Do people normally compile DLLs for page-specific functions that won't be reusable? What approaches make sense for getting our practices under control while still being able to fix old anti-patterns and outdated code and still moving towards a logical structure for future devs to build on?

    Read the article

  • How are the conceptual pairs Abstract/Concrete, Generic/Specific, and Complex/Simple related to one another in software architecture?

    - by tjb1982
    (= 2 (+ 1 1)) take the above. The requirement of the '=' predicate is that its arguments be comparable. Any two structures are comparable in this case, and so the contract/requirement is pretty generic. The '+' predicate requires that its arguments be numbers. That's more specific. (socket domain type protocol) the arguments here are much more specific (even though the arguments are still just numbers and the function itself returns a file descriptor, which is itself an int), but the arguments are more abstract, and the implementation is built up from other functions whose abstractions are less abstract, which are themselves built from less and less abstract abstractions. To the point where the requirements are something like move from one location to another, observe whether the switch at that location is on or off, turn the switch on or off, or leave it the same, etc. But are functions also less and less complex the less abstract they are? And is there a relationship between the number and range of arguments of a function and the complexity of its implementation, as you go from more abstract to less abstract, and vice versa? (= 2 (+ 1 1) 2r10) the '=' predicate is more generic than the '+' predicate, and thus could be more complex in its implementation. The '+' predicate's contract is less generic, and so could be less complex in its implementation. Is this even a little correct? What about the 'socket' function? Each of those arguments is a number of some kind. What they represent, though, is something more elaborate. It also returns a number (just like the others do), which is also a representation of something conceptually much more elaborate than a number. To boil it down, I'm asking if there is a relationship between the following dimensions, and why: Abstract/Concrete Complex/Simple Generic/Specific And more specifically, do different configurations of these dimensions have a specific, measurable impact on the number and range of the arguments (i.e., the contract) of a function?

    Read the article

  • What's is the point of PImpl pattern while we can use interface for same purpose in C++?

    - by ZijingWu
    I see a lot of source code which using PIMPL idiom in C++. I assume Its purposes are hidden the private data/type/implementation, so it can resolve dependence, and then reduce compile time and header include issue. But interface class in C++ also have this capability, it can also used to hidden data/type and implementation. And to hidden let the caller just see the interface when create object, we can add an factory method in it declaration in interface header. The comparison is: Cost: The interface way cost is lower, because you doesn't even need to repeat the public wrapper function implementation void Bar::doWork() { return m_impl->doWork(); }, you just need to define the signature in the interface. Well understand: The interface technology is more well understand by every C++ developer. Performance: Interface way performance not worse than PIMPL idiom, both an extra memory access. I assume the performance is same. Following is the pseudocode code to illustrate my question: // Forward declaration can help you avoid include BarImpl header, and those included in BarImpl header. class BarImpl; class Bar { public: // public functions void doWork(); private: // You doesn't need to compile Bar.cpp after change the implementation in BarImpl.cpp BarImpl* m_impl; }; The same purpose can be implement using interface: // Bar.h class IBar { public: virtual ~IBar(){} // public functions virtual void doWork() = 0; }; // to only expose the interface instead of class name to caller IBar* createObject(); So what's the point of PIMPL?

    Read the article

< Previous Page | 107 108 109 110 111 112 113 114 115 116 117 118  | Next Page >