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  • how to pass a string to an already opened activity?

    - by Hossein Mansouri
    I have 3 Activities A1,A2,A3 A1 call A2 (A1 goes to stack) A2 call A3 (A2 also goes to stack) And A3 call A1 (A1 should call from stack not new instance...) I don't want to Create new instance of A1 just i want to call it from stack I want to send some Extra String to A1, the problem is here, when i send some String by using putExtra() to A1, A1 can not seen it! I put getIntent() in onResume() for A1 but it s not working... Code in A3 Intent in = new Intent(A3.this,A1.class); in.putExtra("ACTIVITY", "A3"); in.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_SINGLE_TOP); startActivity(in); Code in A1 @Override protected void onResume() { super.onResume(); if(getIntent().getExtras().getString("ACTIVITY")=="A3"){ new LoadAllMyOrders().execute(); }else{ new LoadAllMyshops().execute(); } }

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  • Where best to instantiate and close a Silverlight-enabled WCF Service from the Silverlight app?

    - by Yttrium
    When using a Silverlight-enabled WCF service, where is the best place to instantiate the service and to call the CloseAsync() method? Should you say, instantiate an instance each time you need to make a call to the service, or is it better to just instantiate an instance as a variable of the UserControl that will be making the calls? Then, where is it better to call the CloseAsync method? Should you call it in each of the "someServiceCall_completed" event methods? Or, if created as a variable of the UserControl class, is there a single place to call it? Like a Dispose method, or something equivalent for the UserControl class. Thanks, Jeff

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  • Calling a Sub or Function contained in a module using "CallByName" in VB/VBA

    - by Kratz
    It is easy to call a function inside a classModule using CallByName How about functions inside standard module? 'inside class module 'classModule name: clsExample Function classFunc1() MsgBox "I'm class module 1" End Function ' 'inside standard module 'Module name: module1 Function Func1() MsgBox "I'm standard module 1" End Function ' ' The main sub Sub Main() ' to call function inside class module dim clsObj as New clsExample Call CallByName(clsObj,"ClassFunc1") ' here's the question... how to call a function inside a standard module ' how to declare the object "stdObj" in reference to module1? Call CallByName(stdObj,"Func1") ' is this correct? End Sub

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  • What happens when a OSGi service using JNI is unregistered while in use?

    - by schngrg
    As I understand, OSGi services can be unregistered anytime, including when they are in use. Consider an OSGi service which internally makes a long-running JNI call. And while that JNI call is executing, the service is unregistered by OSGi. Will the JNI call be allowed to finish or terminated mid-way? What if it was just a normal non-jni long running Java call? Will that call be allowed to finish execution or will OSGi terminate everything immediately and unregister? What is the expected behavior in such a case? Does the expected behavior depend on if the service was loaded using a 'tracker' or not? SG

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  • Acceptable name for extension method that accept null

    - by GaryX
    Hi, I really don't like to call String.IsNullOrEmpty(str). That makes me need to think "String" class first, then call it on the object "str". I like to call str.IsNullOrEmpty(), which doesn't need me to think "String" class. The problem is that extension method accept null instance to call on, which is not the usual case when you call a normal method. My question what do you think will be a convetion name for extension methods that accept null? For string, that is easy, "IsNullOrEmpty()" (anything that contains "IsNull") sounds good for me. For others, like GetDisplayName(), do we name it as "NullOrGetDisplayName" ?

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  • The Incremental Architect&rsquo;s Napkin - #5 - Design functions for extensibility and readability

    - by Ralf Westphal
    Originally posted on: http://geekswithblogs.net/theArchitectsNapkin/archive/2014/08/24/the-incremental-architectrsquos-napkin---5---design-functions-for.aspx The functionality of programs is entered via Entry Points. So what we´re talking about when designing software is a bunch of functions handling the requests represented by and flowing in through those Entry Points. Designing software thus consists of at least three phases: Analyzing the requirements to find the Entry Points and their signatures Designing the functionality to be executed when those Entry Points get triggered Implementing the functionality according to the design aka coding I presume, you´re familiar with phase 1 in some way. And I guess you´re proficient in implementing functionality in some programming language. But in my experience developers in general are not experienced in going through an explicit phase 2. “Designing functionality? What´s that supposed to mean?” you might already have thought. Here´s my definition: To design functionality (or functional design for short) means thinking about… well, functions. You find a solution for what´s supposed to happen when an Entry Point gets triggered in terms of functions. A conceptual solution that is, because those functions only exist in your head (or on paper) during this phase. But you may have guess that, because it´s “design” not “coding”. And here is, what functional design is not: It´s not about logic. Logic is expressions (e.g. +, -, && etc.) and control statements (e.g. if, switch, for, while etc.). Also I consider calling external APIs as logic. It´s equally basic. It´s what code needs to do in order to deliver some functionality or quality. Logic is what´s doing that needs to be done by software. Transformations are either done through expressions or API-calls. And then there is alternative control flow depending on the result of some expression. Basically it´s just jumps in Assembler, sometimes to go forward (if, switch), sometimes to go backward (for, while, do). But calling your own function is not logic. It´s not necessary to produce any outcome. Functionality is not enhanced by adding functions (subroutine calls) to your code. Nor is quality increased by adding functions. No performance gain, no higher scalability etc. through functions. Functions are not relevant to functionality. Strange, isn´t it. What they are important for is security of investment. By introducing functions into our code we can become more productive (re-use) and can increase evolvability (higher unterstandability, easier to keep code consistent). That´s no small feat, however. Evolvable code can hardly be overestimated. That´s why to me functional design is so important. It´s at the core of software development. To sum this up: Functional design is on a level of abstraction above (!) logical design or algorithmic design. Functional design is only done until you get to a point where each function is so simple you are very confident you can easily code it. Functional design an logical design (which mostly is coding, but can also be done using pseudo code or flow charts) are complementary. Software needs both. If you start coding right away you end up in a tangled mess very quickly. Then you need back out through refactoring. Functional design on the other hand is bloodless without actual code. It´s just a theory with no experiments to prove it. But how to do functional design? An example of functional design Let´s assume a program to de-duplicate strings. The user enters a number of strings separated by commas, e.g. a, b, a, c, d, b, e, c, a. And the program is supposed to clear this list of all doubles, e.g. a, b, c, d, e. There is only one Entry Point to this program: the user triggers the de-duplication by starting the program with the string list on the command line C:\>deduplicate "a, b, a, c, d, b, e, c, a" a, b, c, d, e …or by clicking on a GUI button. This leads to the Entry Point function to get called. It´s the program´s main function in case of the batch version or a button click event handler in the GUI version. That´s the physical Entry Point so to speak. It´s inevitable. What then happens is a three step process: Transform the input data from the user into a request. Call the request handler. Transform the output of the request handler into a tangible result for the user. Or to phrase it a bit more generally: Accept input. Transform input into output. Present output. This does not mean any of these steps requires a lot of effort. Maybe it´s just one line of code to accomplish it. Nevertheless it´s a distinct step in doing the processing behind an Entry Point. Call it an aspect or a responsibility - and you will realize it most likely deserves a function of its own to satisfy the Single Responsibility Principle (SRP). Interestingly the above list of steps is already functional design. There is no logic, but nevertheless the solution is described - albeit on a higher level of abstraction than you might have done yourself. But it´s still on a meta-level. The application to the domain at hand is easy, though: Accept string list from command line De-duplicate Present de-duplicated strings on standard output And this concrete list of processing steps can easily be transformed into code:static void Main(string[] args) { var input = Accept_string_list(args); var output = Deduplicate(input); Present_deduplicated_string_list(output); } Instead of a big problem there are three much smaller problems now. If you think each of those is trivial to implement, then go for it. You can stop the functional design at this point. But maybe, just maybe, you´re not so sure how to go about with the de-duplication for example. Then just implement what´s easy right now, e.g.private static string Accept_string_list(string[] args) { return args[0]; } private static void Present_deduplicated_string_list( string[] output) { var line = string.Join(", ", output); Console.WriteLine(line); } Accept_string_list() contains logic in the form of an API-call. Present_deduplicated_string_list() contains logic in the form of an expression and an API-call. And then repeat the functional design for the remaining processing step. What´s left is the domain logic: de-duplicating a list of strings. How should that be done? Without any logic at our disposal during functional design you´re left with just functions. So which functions could make up the de-duplication? Here´s a suggestion: De-duplicate Parse the input string into a true list of strings. Register each string in a dictionary/map/set. That way duplicates get cast away. Transform the data structure into a list of unique strings. Processing step 2 obviously was the core of the solution. That´s where real creativity was needed. That´s the core of the domain. But now after this refinement the implementation of each step is easy again:private static string[] Parse_string_list(string input) { return input.Split(',') .Select(s => s.Trim()) .ToArray(); } private static Dictionary<string,object> Compile_unique_strings(string[] strings) { return strings.Aggregate( new Dictionary<string, object>(), (agg, s) => { agg[s] = null; return agg; }); } private static string[] Serialize_unique_strings( Dictionary<string,object> dict) { return dict.Keys.ToArray(); } With these three additional functions Main() now looks like this:static void Main(string[] args) { var input = Accept_string_list(args); var strings = Parse_string_list(input); var dict = Compile_unique_strings(strings); var output = Serialize_unique_strings(dict); Present_deduplicated_string_list(output); } I think that´s very understandable code: just read it from top to bottom and you know how the solution to the problem works. It´s a mirror image of the initial design: Accept string list from command line Parse the input string into a true list of strings. Register each string in a dictionary/map/set. That way duplicates get cast away. Transform the data structure into a list of unique strings. Present de-duplicated strings on standard output You can even re-generate the design by just looking at the code. Code and functional design thus are always in sync - if you follow some simple rules. But about that later. And as a bonus: all the functions making up the process are small - which means easy to understand, too. So much for an initial concrete example. Now it´s time for some theory. Because there is method to this madness ;-) The above has only scratched the surface. Introducing Flow Design Functional design starts with a given function, the Entry Point. Its goal is to describe the behavior of the program when the Entry Point is triggered using a process, not an algorithm. An algorithm consists of logic, a process on the other hand consists just of steps or stages. Each processing step transforms input into output or a side effect. Also it might access resources, e.g. a printer, a database, or just memory. Processing steps thus can rely on state of some sort. This is different from Functional Programming, where functions are supposed to not be stateful and not cause side effects.[1] In its simplest form a process can be written as a bullet point list of steps, e.g. Get data from user Output result to user Transform data Parse data Map result for output Such a compilation of steps - possibly on different levels of abstraction - often is the first artifact of functional design. It can be generated by a team in an initial design brainstorming. Next comes ordering the steps. What should happen first, what next etc.? Get data from user Parse data Transform data Map result for output Output result to user That´s great for a start into functional design. It´s better than starting to code right away on a given function using TDD. Please get me right: TDD is a valuable practice. But it can be unnecessarily hard if the scope of a functionn is too large. But how do you know beforehand without investing some thinking? And how to do this thinking in a systematic fashion? My recommendation: For any given function you´re supposed to implement first do a functional design. Then, once you´re confident you know the processing steps - which are pretty small - refine and code them using TDD. You´ll see that´s much, much easier - and leads to cleaner code right away. For more information on this approach I call “Informed TDD” read my book of the same title. Thinking before coding is smart. And writing down the solution as a bunch of functions possibly is the simplest thing you can do, I´d say. It´s more according to the KISS (Keep It Simple, Stupid) principle than returning constants or other trivial stuff TDD development often is started with. So far so good. A simple ordered list of processing steps will do to start with functional design. As shown in the above example such steps can easily be translated into functions. Moving from design to coding thus is simple. However, such a list does not scale. Processing is not always that simple to be captured in a list. And then the list is just text. Again. Like code. That means the design is lacking visuality. Textual representations need more parsing by your brain than visual representations. Plus they are limited in their “dimensionality”: text just has one dimension, it´s sequential. Alternatives and parallelism are hard to encode in text. In addition the functional design using numbered lists lacks data. It´s not visible what´s the input, output, and state of the processing steps. That´s why functional design should be done using a lightweight visual notation. No tool is necessary to draw such designs. Use pen and paper; a flipchart, a whiteboard, or even a napkin is sufficient. Visualizing processes The building block of the functional design notation is a functional unit. I mostly draw it like this: Something is done, it´s clear what goes in, it´s clear what comes out, and it´s clear what the processing step requires in terms of state or hardware. Whenever input flows into a functional unit it gets processed and output is produced and/or a side effect occurs. Flowing data is the driver of something happening. That´s why I call this approach to functional design Flow Design. It´s about data flow instead of control flow. Control flow like in algorithms is of no concern to functional design. Thinking about control flow simply is too low level. Once you start with control flow you easily get bogged down by tons of details. That´s what you want to avoid during design. Design is supposed to be quick, broad brush, abstract. It should give overview. But what about all the details? As Robert C. Martin rightly said: “Programming is abot detail”. Detail is a matter of code. Once you start coding the processing steps you designed you can worry about all the detail you want. Functional design does not eliminate all the nitty gritty. It just postpones tackling them. To me that´s also an example of the SRP. Function design has the responsibility to come up with a solution to a problem posed by a single function (Entry Point). And later coding has the responsibility to implement the solution down to the last detail (i.e. statement, API-call). TDD unfortunately mixes both responsibilities. It´s just coding - and thereby trying to find detailed implementations (green phase) plus getting the design right (refactoring). To me that´s one reason why TDD has failed to deliver on its promise for many developers. Using functional units as building blocks of functional design processes can be depicted very easily. Here´s the initial process for the example problem: For each processing step draw a functional unit and label it. Choose a verb or an “action phrase” as a label, not a noun. Functional design is about activities, not state or structure. Then make the output of an upstream step the input of a downstream step. Finally think about the data that should flow between the functional units. Write the data above the arrows connecting the functional units in the direction of the data flow. Enclose the data description in brackets. That way you can clearly see if all flows have already been specified. Empty brackets mean “no data is flowing”, but nevertheless a signal is sent. A name like “list” or “strings” in brackets describes the data content. Use lower case labels for that purpose. A name starting with an upper case letter like “String” or “Customer” on the other hand signifies a data type. If you like, you also can combine descriptions with data types by separating them with a colon, e.g. (list:string) or (strings:string[]). But these are just suggestions from my practice with Flow Design. You can do it differently, if you like. Just be sure to be consistent. Flows wired-up in this manner I call one-dimensional (1D). Each functional unit just has one input and/or one output. A functional unit without an output is possible. It´s like a black hole sucking up input without producing any output. Instead it produces side effects. A functional unit without an input, though, does make much sense. When should it start to work? What´s the trigger? That´s why in the above process even the first processing step has an input. If you like, view such 1D-flows as pipelines. Data is flowing through them from left to right. But as you can see, it´s not always the same data. It get´s transformed along its passage: (args) becomes a (list) which is turned into (strings). The Principle of Mutual Oblivion A very characteristic trait of flows put together from function units is: no functional units knows another one. They are all completely independent of each other. Functional units don´t know where their input is coming from (or even when it´s gonna arrive). They just specify a range of values they can process. And they promise a certain behavior upon input arriving. Also they don´t know where their output is going. They just produce it in their own time independent of other functional units. That means at least conceptually all functional units work in parallel. Functional units don´t know their “deployment context”. They now nothing about the overall flow they are place in. They are just consuming input from some upstream, and producing output for some downstream. That makes functional units very easy to test. At least as long as they don´t depend on state or resources. I call this the Principle of Mutual Oblivion (PoMO). Functional units are oblivious of others as well as an overall context/purpose. They are just parts of a whole focused on a single responsibility. How the whole is built, how a larger goal is achieved, is of no concern to the single functional units. By building software in such a manner, functional design interestingly follows nature. Nature´s building blocks for organisms also follow the PoMO. The cells forming your body do not know each other. Take a nerve cell “controlling” a muscle cell for example:[2] The nerve cell does not know anything about muscle cells, let alone the specific muscel cell it is “attached to”. Likewise the muscle cell does not know anything about nerve cells, let a lone a specific nerve cell “attached to” it. Saying “the nerve cell is controlling the muscle cell” thus only makes sense when viewing both from the outside. “Control” is a concept of the whole, not of its parts. Control is created by wiring-up parts in a certain way. Both cells are mutually oblivious. Both just follow a contract. One produces Acetylcholine (ACh) as output, the other consumes ACh as input. Where the ACh is going, where it´s coming from neither cell cares about. Million years of evolution have led to this kind of division of labor. And million years of evolution have produced organism designs (DNA) which lead to the production of these different cell types (and many others) and also to their co-location. The result: the overall behavior of an organism. How and why this happened in nature is a mystery. For our software, though, it´s clear: functional and quality requirements needs to be fulfilled. So we as developers have to become “intelligent designers” of “software cells” which we put together to form a “software organism” which responds in satisfying ways to triggers from it´s environment. My bet is: If nature gets complex organisms working by following the PoMO, who are we to not apply this recipe for success to our much simpler “machines”? So my rule is: Wherever there is functionality to be delivered, because there is a clear Entry Point into software, design the functionality like nature would do it. Build it from mutually oblivious functional units. That´s what Flow Design is about. In that way it´s even universal, I´d say. Its notation can also be applied to biology: Never mind labeling the functional units with nouns. That´s ok in Flow Design. You´ll do that occassionally for functional units on a higher level of abstraction or when their purpose is close to hardware. Getting a cockroach to roam your bedroom takes 1,000,000 nerve cells (neurons). Getting the de-duplication program to do its job just takes 5 “software cells” (functional units). Both, though, follow the same basic principle. Translating functional units into code Moving from functional design to code is no rocket science. In fact it´s straightforward. There are two simple rules: Translate an input port to a function. Translate an output port either to a return statement in that function or to a function pointer visible to that function. The simplest translation of a functional unit is a function. That´s what you saw in the above example. Functions are mutually oblivious. That why Functional Programming likes them so much. It makes them composable. Which is the reason, nature works according to the PoMO. Let´s be clear about one thing: There is no dependency injection in nature. For all of an organism´s complexity no DI container is used. Behavior is the result of smooth cooperation between mutually oblivious building blocks. Functions will often be the adequate translation for the functional units in your designs. But not always. Take for example the case, where a processing step should not always produce an output. Maybe the purpose is to filter input. Here the functional unit consumes words and produces words. But it does not pass along every word flowing in. Some words are swallowed. Think of a spell checker. It probably should not check acronyms for correctness. There are too many of them. Or words with no more than two letters. Such words are called “stop words”. In the above picture the optionality of the output is signified by the astrisk outside the brackets. It means: Any number of (word) data items can flow from the functional unit for each input data item. It might be none or one or even more. This I call a stream of data. Such behavior cannot be translated into a function where output is generated with return. Because a function always needs to return a value. So the output port is translated into a function pointer or continuation which gets passed to the subroutine when called:[3]void filter_stop_words( string word, Action<string> onNoStopWord) { if (...check if not a stop word...) onNoStopWord(word); } If you want to be nitpicky you might call such a function pointer parameter an injection. And technically you´re right. Conceptually, though, it´s not an injection. Because the subroutine is not functionally dependent on the continuation. Firstly continuations are procedures, i.e. subroutines without a return type. Remember: Flow Design is about unidirectional data flow. Secondly the name of the formal parameter is chosen in a way as to not assume anything about downstream processing steps. onNoStopWord describes a situation (or event) within the functional unit only. Translating output ports into function pointers helps keeping functional units mutually oblivious in cases where output is optional or produced asynchronically. Either pass the function pointer to the function upon call. Or make it global by putting it on the encompassing class. Then it´s called an event. In C# that´s even an explicit feature.class Filter { public void filter_stop_words( string word) { if (...check if not a stop word...) onNoStopWord(word); } public event Action<string> onNoStopWord; } When to use a continuation and when to use an event dependens on how a functional unit is used in flows and how it´s packed together with others into classes. You´ll see examples further down the Flow Design road. Another example of 1D functional design Let´s see Flow Design once more in action using the visual notation. How about the famous word wrap kata? Robert C. Martin has posted a much cited solution including an extensive reasoning behind his TDD approach. So maybe you want to compare it to Flow Design. The function signature given is:string WordWrap(string text, int maxLineLength) {...} That´s not an Entry Point since we don´t see an application with an environment and users. Nevertheless it´s a function which is supposed to provide a certain functionality. The text passed in has to be reformatted. The input is a single line of arbitrary length consisting of words separated by spaces. The output should consist of one or more lines of a maximum length specified. If a word is longer than a the maximum line length it can be split in multiple parts each fitting in a line. Flow Design Let´s start by brainstorming the process to accomplish the feat of reformatting the text. What´s needed? Words need to be assembled into lines Words need to be extracted from the input text The resulting lines need to be assembled into the output text Words too long to fit in a line need to be split Does sound about right? I guess so. And it shows a kind of priority. Long words are a special case. So maybe there is a hint for an incremental design here. First let´s tackle “average words” (words not longer than a line). Here´s the Flow Design for this increment: The the first three bullet points turned into functional units with explicit data added. As the signature requires a text is transformed into another text. See the input of the first functional unit and the output of the last functional unit. In between no text flows, but words and lines. That´s good to see because thereby the domain is clearly represented in the design. The requirements are talking about words and lines and here they are. But note the asterisk! It´s not outside the brackets but inside. That means it´s not a stream of words or lines, but lists or sequences. For each text a sequence of words is output. For each sequence of words a sequence of lines is produced. The asterisk is used to abstract from the concrete implementation. Like with streams. Whether the list of words gets implemented as an array or an IEnumerable is not important during design. It´s an implementation detail. Does any processing step require further refinement? I don´t think so. They all look pretty “atomic” to me. And if not… I can always backtrack and refine a process step using functional design later once I´ve gained more insight into a sub-problem. Implementation The implementation is straightforward as you can imagine. The processing steps can all be translated into functions. Each can be tested easily and separately. Each has a focused responsibility. And the process flow becomes just a sequence of function calls: Easy to understand. It clearly states how word wrapping works - on a high level of abstraction. And it´s easy to evolve as you´ll see. Flow Design - Increment 2 So far only texts consisting of “average words” are wrapped correctly. Words not fitting in a line will result in lines too long. Wrapping long words is a feature of the requested functionality. Whether it´s there or not makes a difference to the user. To quickly get feedback I decided to first implement a solution without this feature. But now it´s time to add it to deliver the full scope. Fortunately Flow Design automatically leads to code following the Open Closed Principle (OCP). It´s easy to extend it - instead of changing well tested code. How´s that possible? Flow Design allows for extension of functionality by inserting functional units into the flow. That way existing functional units need not be changed. The data flow arrow between functional units is a natural extension point. No need to resort to the Strategy Pattern. No need to think ahead where extions might need to be made in the future. I just “phase in” the remaining processing step: Since neither Extract words nor Reformat know of their environment neither needs to be touched due to the “detour”. The new processing step accepts the output of the existing upstream step and produces data compatible with the existing downstream step. Implementation - Increment 2 A trivial implementation checking the assumption if this works does not do anything to split long words. The input is just passed on: Note how clean WordWrap() stays. The solution is easy to understand. A developer looking at this code sometime in the future, when a new feature needs to be build in, quickly sees how long words are dealt with. Compare this to Robert C. Martin´s solution:[4] How does this solution handle long words? Long words are not even part of the domain language present in the code. At least I need considerable time to understand the approach. Admittedly the Flow Design solution with the full implementation of long word splitting is longer than Robert C. Martin´s. At least it seems. Because his solution does not cover all the “word wrap situations” the Flow Design solution handles. Some lines would need to be added to be on par, I guess. But even then… Is a difference in LOC that important as long as it´s in the same ball park? I value understandability and openness for extension higher than saving on the last line of code. Simplicity is not just less code, it´s also clarity in design. But don´t take my word for it. Try Flow Design on larger problems and compare for yourself. What´s the easier, more straightforward way to clean code? And keep in mind: You ain´t seen all yet ;-) There´s more to Flow Design than described in this chapter. In closing I hope I was able to give you a impression of functional design that makes you hungry for more. To me it´s an inevitable step in software development. Jumping from requirements to code does not scale. And it leads to dirty code all to quickly. Some thought should be invested first. Where there is a clear Entry Point visible, it´s functionality should be designed using data flows. Because with data flows abstraction is possible. For more background on why that´s necessary read my blog article here. For now let me point out to you - if you haven´t already noticed - that Flow Design is a general purpose declarative language. It´s “programming by intention” (Shalloway et al.). Just write down how you think the solution should work on a high level of abstraction. This breaks down a large problem in smaller problems. And by following the PoMO the solutions to those smaller problems are independent of each other. So they are easy to test. Or you could even think about getting them implemented in parallel by different team members. Flow Design not only increases evolvability, but also helps becoming more productive. All team members can participate in functional design. This goes beyon collective code ownership. We´re talking collective design/architecture ownership. Because with Flow Design there is a common visual language to talk about functional design - which is the foundation for all other design activities.   PS: If you like what you read, consider getting my ebook “The Incremental Architekt´s Napkin”. It´s where I compile all the articles in this series for easier reading. I like the strictness of Function Programming - but I also find it quite hard to live by. And it certainly is not what millions of programmers are used to. Also to me it seems, the real world is full of state and side effects. So why give them such a bad image? That´s why functional design takes a more pragmatic approach. State and side effects are ok for processing steps - but be sure to follow the SRP. Don´t put too much of it into a single processing step. ? Image taken from www.physioweb.org ? My code samples are written in C#. C# sports typed function pointers called delegates. Action is such a function pointer type matching functions with signature void someName(T t). Other languages provide similar ways to work with functions as first class citizens - even Java now in version 8. I trust you find a way to map this detail of my translation to your favorite programming language. I know it works for Java, C++, Ruby, JavaScript, Python, Go. And if you´re using a Functional Programming language it´s of course a no brainer. ? Taken from his blog post “The Craftsman 62, The Dark Path”. ?

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  • Integration Patterns with Azure Service Bus Relay, Part 3.5: Node.js relay

    - by Elton Stoneman
    This is an extension to Part 3 in the IPASBR series, see also: Integration Patterns with Azure Service Bus Relay, Part 1: Exposing the on-premise service Integration Patterns with Azure Service Bus Relay, Part 2: Anonymous full-trust .NET consumer Integration Patterns with Azure Service Bus Relay, Part 3: Anonymous partial-trust consumer In Part 3 I said “there isn't actually a .NET requirement here”, and this post just follows up on that statement. In Part 3 we had an ASP.NET MVC Website making a REST call to an Azure Service Bus service; to show that the REST stuff is really interoperable, in this version we use Node.js to make the secure service call. The code is on GitHub here: IPASBR Part 3.5. The sample code is simpler than Part 3 - rather than code up a UI in Node.js, the sample just relays the REST service call out to Azure. The steps are the same as Part 3: REST call to ACS with the service identity credentials, which returns an SWT; REST call to Azure Service Bus Relay, presenting the SWT; request gets relayed to the on-premise service. In Node.js the authentication step looks like this: var options = { host: acs.namespace() + '-sb.accesscontrol.windows.net', path: '/WRAPv0.9/', method: 'POST' }; var values = { wrap_name: acs.issuerName(), wrap_password: acs.issuerSecret(), wrap_scope: 'http://' + acs.namespace() + '.servicebus.windows.net/' }; var req = https.request(options, function (res) { console.log("statusCode: ", res.statusCode); console.log("headers: ", res.headers); res.on('data', function (d) { var token = qs.parse(d.toString('utf8')); callback(token.wrap_access_token); }); }); req.write(qs.stringify(values)); req.end(); Once we have the token, we can wrap it up into an Authorization header and pass it to the Service Bus call: token = 'WRAP access_token=\"' + swt + '\"'; //... var reqHeaders = { Authorization: token }; var options = { host: acs.namespace() + '.servicebus.windows.net', path: '/rest/reverse?string=' + requestUrl.query.string, headers: reqHeaders }; var req = https.request(options, function (res) { console.log("statusCode: ", res.statusCode); console.log("headers: ", res.headers); response.writeHead(res.statusCode, res.headers); res.on('data', function (d) { var reversed = d.toString('utf8') console.log('svc returned: ' + d.toString('utf8')); response.end(reversed); }); }); req.end(); Running the sample Usual routine to add your own Azure details into Solution Items\AzureConnectionDetails.xml and “Run Custom Tool” on the .tt files. Build and you should be able to navigate to the on-premise service at http://localhost/Sixeyed.Ipasbr.Services/FormatService.svc/rest/reverse?string=abc123 and get a string response, going to the service direct. Install Node.js (v0.8.14 at time of writing), run FormatServiceRelay.cmd, navigate to http://localhost:8013/reverse?string=abc123, and you should get exactly the same response but through Node.js, via Azure Service Bus Relay to your on-premise service. The console logs the WRAP token returned from ACS and the response from Azure Service Bus Relay which it forwards:

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  • Gnome Shell Theme Problem on Ubuntu 11.10

    - by Khurram Majeed
    I am trying to install ANewStart GNOME shell themes on Ubuntu 11.10. I have installed gnome shell extension for themes: sudo add-apt-repository ppa:webupd8team/gnome3 sudo apt-get update sudo apt-get install gnome-shell-extensions-user-theme I got the instructions from here ANewStart GNOME Shell Theme + AwOken Icons Theme = Pure Art. But when I go to "Advanced Settings - Shell Extensions" its empty... There is nothing. Also there is a orange triangle sign next to Shell Theme drop down in Advanced Settings - Theme. When I try to run the gnome-tweak-tool from terminal I get following error: imresh@imresh-laptop:~$ gnome-tweak-tool CRITICAL: Error parsing schema org.gnome.shell (/usr/share/glib-2.0/schemas/org.gnome.shell.gschema.xml) Traceback (most recent call last): File "/usr/lib/python2.7/dist-packages/gtweak/gsettings.py", line 45, in __init__ summary = key.getElementsByTagName("summary")[0].childNodes[0].data IndexError: list index out of range WARNING : Error detecting shell Traceback (most recent call last): File "/usr/lib/python2.7/dist-packages/gtweak/tweaks/tweak_shell_extensions.py", line 145, in __init__ shell = GnomeShellFactory().get_shell() File "/usr/lib/python2.7/dist-packages/gtweak/utils.py", line 38, in getinstance instances[cls] = cls() File "/usr/lib/python2.7/dist-packages/gtweak/gshellwrapper.py", line 123, in __init__ v = map(int,proxy.version.split(".")) File "/usr/lib/python2.7/dist-packages/gtweak/gshellwrapper.py", line 46, in version return json.loads(self.execute_js('const Config = imports.misc.config; Config.PACKAGE_VERSION')) File "/usr/lib/python2.7/dist-packages/gtweak/gshellwrapper.py", line 39, in execute_js result, output = self.proxy.Eval('(s)', js) File "/usr/lib/python2.7/dist-packages/gi/overrides/Gio.py", line 148, in __call__ kwargs.get('flags', 0), kwargs.get('timeout', -1), None) File "/usr/lib/python2.7/dist-packages/gi/types.py", line 43, in function return info.invoke(*args, **kwargs) GError: GDBus.Error:org.freedesktop.DBus.Error.ServiceUnknown: The name org.gnome.Shell was not provided by any .service files WARNING : Shell not running Traceback (most recent call last): File "/usr/lib/python2.7/dist-packages/gtweak/tweaks/tweak_shell.py", line 57, in __init__ self._shell = GnomeShellFactory().get_shell() File "/usr/lib/python2.7/dist-packages/gtweak/utils.py", line 38, in getinstance instances[cls] = cls() File "/usr/lib/python2.7/dist-packages/gtweak/gshellwrapper.py", line 123, in __init__ v = map(int,proxy.version.split(".")) File "/usr/lib/python2.7/dist-packages/gtweak/gshellwrapper.py", line 46, in version return json.loads(self.execute_js('const Config = imports.misc.config; Config.PACKAGE_VERSION')) File "/usr/lib/python2.7/dist-packages/gtweak/gshellwrapper.py", line 39, in execute_js result, output = self.proxy.Eval('(s)', js) File "/usr/lib/python2.7/dist-packages/gi/overrides/Gio.py", line 148, in __call__ kwargs.get('flags', 0), kwargs.get('timeout', -1), None) File "/usr/lib/python2.7/dist-packages/gi/types.py", line 43, in function return info.invoke(*args, **kwargs) GError: GDBus.Error:org.freedesktop.DBus.Error.ServiceUnknown: The name org.gnome.Shell was not provided by any .service files WARNING : Could not list shell extensions Traceback (most recent call last): File "/usr/lib/python2.7/dist-packages/gtweak/tweaks/tweak_shell.py", line 62, in __init__ extensions = self._shell.list_extensions() AttributeError: ShellThemeTweak instance has no attribute '_shell' (gnome-tweak-tool:5323): Gtk-CRITICAL **: gtk_widget_get_preferred_height_for_width: assertion `width >= 0' failed (gnome-tweak-tool:5323): Gtk-CRITICAL **: gtk_widget_get_preferred_height_for_width: assertion `width >= 0' failed (gnome-tweak-tool:5323): Gtk-CRITICAL **: gtk_widget_get_preferred_height_for_width: assertion `width >= 0' failed (gnome-tweak-tool:5323): Gtk-CRITICAL **: gtk_widget_get_preferred_height_for_width: assertion `width >= 0' failed (gnome-tweak-tool:5323): Gtk-CRITICAL **: gtk_widget_get_preferred_height_for_width: assertion `width >= 0' failed (gnome-tweak-tool:5323): Gtk-CRITICAL **: gtk_widget_get_preferred_height_for_width: assertion `width >= 0' failed (gnome-tweak-tool:5323): Gtk-CRITICAL **: gtk_widget_get_preferred_height_for_width: assertion `width >= 0' failed (gnome-tweak-tool:5323): Gtk-CRITICAL **: gtk_widget_get_preferred_height_for_width: assertion `width >= 0' failed (gnome-tweak-tool:5323): Gtk-CRITICAL **: gtk_widget_get_preferred_height_for_width: assertion `width >= 0' failed (gnome-tweak-tool:5323): Gtk-CRITICAL **: gtk_widget_get_preferred_height_for_width: assertion `width >= 0' failed (gnome-tweak-tool:5323): Gtk-CRITICAL **: gtk_widget_get_preferred_height_for_width: assertion `width >= 0' failed (gnome-tweak-tool:5323): Gtk-CRITICAL **: gtk_widget_get_preferred_height_for_width: assertion `width >= 0' failed (gnome-tweak-tool:5323): Gtk-CRITICAL **: gtk_widget_get_preferred_height_for_width: assertion `width >= 0' failed (gnome-tweak-tool:5323): Gtk-CRITICAL **: gtk_widget_get_preferred_height_for_width: assertion `width >= 0' failed (gnome-tweak-tool:5323): Gtk-CRITICAL **: gtk_widget_get_preferred_height_for_width: assertion `width >= 0' failed Please help me in fixing this. I have also restarted the computer many times it does not make a difference.

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  • DirectX particle system. ConstantBuffer

    - by Liuka
    I'm new in DirectX and I'm making a 2D game. I want to use a particle system to simulate a 3D starfield, so each star has to set its own constant buffer for the vertexshader es. to set it's world matrix. So if i have 500 stars (that move every frame) i need to call 500 times VSsetconstantbuffer, and map/unmap each buffer. with 500 stars i have an average of 220 fps and that's quite good. My bottelneck is Vs/PsSetconstantbuffer. If i dont call this function i have 400 fps(obliviously nothing is display, since i dont set the position of the stars). So is there a method to speed up the render of the particle system?? Ps. I'm using intel integrate graphic (hd 2000-3000). with a nvidia (or amd) gpu will i have the same bottleneck?? If, for example, i dont call setshaderresource i have 10-20 fps more (for 500 objcets), that is not 180.Why does SetConstantBuffer take so long?? LPVOID VSdataPtr = VSmappedResource.pData; memcpy(VSdataPtr, VSdata, CszVSdata); context->Unmap(VertexBuffer, 0); result = context->Map(PixelBuffer, 0, D3D11_MAP_WRITE_DISCARD, 0, &PSmappedResource); if (FAILED(result)) { outputResult.OutputErrorMessage(TITLE, L"Cannot map the PixelBuffer", &result, OUTPUT_ERROR_FILE); return; } LPVOID PSdataPtr = PSmappedResource.pData; memcpy(PSdataPtr, PSdata, CszPSdata); context->Unmap(PixelBuffer, 0); context->VSSetConstantBuffers(0, 1, &VertexBuffer); context->PSSetConstantBuffers(0, 1, &PixelBuffer); this update and set the buffer. It's part of the render method of a sprite class that contains a the vertex buffer and the texture to apply to the quads(it's a 2d game) too. I have an array of 500 stars (sprite setup with a star texture). Every frame: clear back buffer; draw the array of stars; present the backbuffer; draw also call the function update( which calculate the position of the sprite on screen based on a "camera class") Ok, create a vertex buffer with the vertices of each quads(stars) seems to be good, since the stars don't change their "virtual" position; so.... In a particle system (where particles move) it's better to have all the object in only one vertices array, rather then an array of different sprite/object in order to update all the vertices' position with a single setbuffer call. In this case i have to use a dynamic vertex buffer with the vertices positions like this: verticesForQuad={{ XMFLOAT3((float)halfDImensions.x-1+pos.x, (float)halfDImensions.y-1+pos.y, 1.0f), XMFLOAT2(1.0f, 0.0f) }, { XMFLOAT3((float)halfDImensions.x-1+pos.x, -(float)halfDImensions.y-1+pos.y, 1.0f), XMFLOAT2(1.0f, 1.0f) }, { XMFLOAT3(-(float)halfDImensions.x-1+pos.x, (float)halfDImensions.y-1.pos.y, 1.0f), XMFLOAT2(0.0f, 0.0f) }, { XMFLOAT3(-(float)halfDImensions.x-1.pos.x, -(float)halfDImensions.y-1+pos.y, 1.0f), XMFLOAT2(0.0f, 1.0f) }, ....other quads} where halfDimensions is the halfsize in pixel of a texture and pos the virtual position of a star. than create an array of verticesForQuad and create the vertex buffer ZeroMemory(&vertexDesc, sizeof(vertexDesc)); vertexDesc.Usage = D3D11_USAGE_DEFAULT; vertexDesc.BindFlags = D3D11_BIND_VERTEX_BUFFER; vertexDesc.ByteWidth = sizeof(VertexType)* 4*numStars; ZeroMemory(&resourceData, sizeof(resourceData)); resourceData.pSysMem = verticesForQuad; result = device->CreateBuffer(&vertexDesc, &resourceData, &CvertexBuffer); and call each frame Context->IASetVertexBuffers(0, 1, &CvertexBuffer, &stride, &offset); But if i want to add and remove obj i have to recreate the buffer each time, havent i?? There is a faster way? I think i can create a vertex buffer with a max size (es. 10000 objs) and when i update it set only the 250 position (for 250 onjs for example) and pass this number as the vertexCount to the draw function (numObjs*4), or i'm worng

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  • I need to modify a program to use arrays and a method call. Should I modify the running file, the data collection file, or both?

    - by g3n3rallyl0st
    I have to have multiple classes for this program. The problem is, I don't fully understand arrays and how they work, so I'm a little lost. I will post my program I have written thus far so you can see what I'm working with, but I don't expect anyone to DO my assignment for me. I just need to know where to start and I'll try to go from there. I think I need to use a double array since I will be working with decimals since it deals with money, and my method call needs to calculate total price for all items entered by the user. Please help: RUNNING FILE package inventory2; import java.util.Scanner; public class RunApp { public static void main(String[] args) { Scanner input = new Scanner( System.in ); DataCollection theProduct = new DataCollection(); String Name = ""; double pNumber = 0.0; double Units = 0.0; double Price = 0.0; while(true) { System.out.print("Enter Product Name: "); Name = input.next(); theProduct.setName(Name); if (Name.equalsIgnoreCase("stop")) { return; } System.out.print("Enter Product Number: "); pNumber = input.nextDouble(); theProduct.setpNumber(pNumber); System.out.print("Enter How Many Units in Stock: "); Units = input.nextDouble(); theProduct.setUnits(Units); System.out.print("Enter Price Per Unit: "); Price = input.nextDouble(); theProduct.setPrice(Price); System.out.print("\n Product Name: " + theProduct.getName()); System.out.print("\n Product Number: " + theProduct.getpNumber()); System.out.print("\n Amount of Units in Stock: " + theProduct.getUnits()); System.out.print("\n Price per Unit: " + theProduct.getPrice() + "\n\n"); System.out.printf("\n Total cost for %s in stock: $%.2f\n\n\n", theProduct.getName(), theProduct.calculatePrice()); } } } DATA COLLECTION FILE package inventory2; public class DataCollection { String productName; double productNumber, unitsInStock, unitPrice, totalPrice; public DataCollection() { productName = ""; productNumber = 0.0; unitsInStock = 0.0; unitPrice = 0.0; } //setter methods public void setName(String name) { productName = name; } public void setpNumber(double pNumber) { productNumber = pNumber; } public void setUnits(double units) { unitsInStock = units; } public void setPrice(double price) { unitPrice = price; } //getter methods public String getName() { return productName; } public double getpNumber() { return productNumber; } public double getUnits() { return unitsInStock; } public double getPrice() { return unitPrice; } public double calculatePrice() { return (unitsInStock * unitPrice); } }

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  • AppEngine JRuby - OutOfMemoryError: Java heap space - can it be solved?

    - by elado
    I use AppEngine JRuby on Rails (SDK version 1.3.3.1) - a problem I encounter often is that after a few requests the server is getting really SLOW, until it dies and throws OutOfMemoryError on the terminal (OSX). The requests themselves are very lightweight, not more than looking for an entity or saving it, using DataMapper. On appspot, this problem is not happening. Is there any way to enlarge the heap space for JRuby? The exception log: Exception in thread "Timer-2" java.lang.OutOfMemoryError: Java heap space Apr 29, 2010 8:08:22 AM com.google.apphosting.utils.jetty.JettyLogger warn WARNING: Error for /users/close_users java.lang.OutOfMemoryError: Java heap space at org.jruby.RubyHash.internalPut(RubyHash.java:480) at org.jruby.RubyHash.internalPut(RubyHash.java:461) at org.jruby.RubyHash.fastASet(RubyHash.java:837) at org.jruby.RubyArray.makeHash(RubyArray.java:2998) at org.jruby.RubyArray.makeHash(RubyArray.java:2992) at org.jruby.RubyArray.op_diff(RubyArray.java:3103) at org.jruby.RubyArray$i_method_1_0$RUBYINVOKER$op_diff.call(org/jruby/RubyArray$i_method_1_0$RUBYINVOKER$op_diff.gen) at org.jruby.runtime.callsite.CachingCallSite.call(CachingCallSite.java:146) at org.jruby.ast.CallOneArgNode.interpret(CallOneArgNode.java:57) at org.jruby.ast.LocalAsgnNode.interpret(LocalAsgnNode.java:123) at org.jruby.ast.NewlineNode.interpret(NewlineNode.java:104) at org.jruby.ast.BlockNode.interpret(BlockNode.java:71) at org.jruby.runtime.InterpretedBlock.evalBlockBody(InterpretedBlock.java:373) at org.jruby.runtime.InterpretedBlock.yield(InterpretedBlock.java:346) at org.jruby.runtime.InterpretedBlock.yield(InterpretedBlock.java:303) at org.jruby.runtime.Block.yield(Block.java:194) at org.jruby.RubyArray.collect(RubyArray.java:2354) at org.jruby.RubyArray$i_method_0_0$RUBYFRAMEDINVOKER$collect.call(org/jruby/RubyArray$i_method_0_0$RUBYFRAMEDINVOKER$collect.gen) at org.jruby.runtime.callsite.CachingCallSite.callBlock(CachingCallSite.java:115) at org.jruby.runtime.callsite.CachingCallSite.call(CachingCallSite.java:122) at org.jruby.ast.CallNoArgBlockNode.interpret(CallNoArgBlockNode.java:64) at org.jruby.ast.CallNoArgNode.interpret(CallNoArgNode.java:61) at org.jruby.ast.LocalAsgnNode.interpret(LocalAsgnNode.java:123) at org.jruby.ast.NewlineNode.interpret(NewlineNode.java:104) at org.jruby.ast.BlockNode.interpret(BlockNode.java:71) at org.jruby.ast.EnsureNode.interpret(EnsureNode.java:98) at org.jruby.ast.BeginNode.interpret(BeginNode.java:83) at org.jruby.ast.NewlineNode.interpret(NewlineNode.java:104) at org.jruby.ast.BlockNode.interpret(BlockNode.java:71) at org.jruby.ast.EnsureNode.interpret(EnsureNode.java:96) at org.jruby.internal.runtime.methods.InterpretedMethod.call(InterpretedMethod.java:201) at org.jruby.internal.runtime.methods.DefaultMethod.call(DefaultMethod.java:183)

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  • Understanding the Silverlight Dispatcher

    - by Matt
    I had a Invalid Cross Thread access issue, but a little research and I managed to fix it by using the Dispatcher. Now in my app I have objects with lazy loading. I'd make an Async call using WCF and as usual I use the Dispatcher to update my objects DataContext, however it didn't work for this scenario. I did however find a solution here. Here's what I don't understand. In my UserControl I have code to call an Toggle method on my object. The call to this method is within a Dispatcher like so. Dispatcher.BeginInvoke( () => _CurrentPin.ToggleInfoPanel() ); As I mentioned before this was not enough to satisfy Silverlight. I had to make another Dispatcher call within my object. My object is NOT a UIElement, but a simple class that handles all its own loading/saving. So the problem was fixed by calling Deployment.Current.Dispatcher.BeginInvoke( () => dataContext.Detail = detail ); within my class. Why did I have to call the Dispatcher twice to achieve this? Shouldn't a high-level call be enough? Is there a difference between the Deployment.Current.Dispatcher and the Dispatcher in a UIElement?

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  • Vim script to compile TeX source and launch PDF only if no errors

    - by Jeet
    Hi, I am switching to using Vim for for my LaTeX editing environment. I would like to be able to tex the source file from within Vim, and launch an external viewing if the compile was successful. I know about the Vim-Latex suite, but, if possible, would prefer to avoid using it: it is pretty heavy-weight, hijacks a lot of my keys, and clutters up my vimruntime with a lot of files. Here is what I have now: if exists('b:tex_build_mapped') finish endif " use maparg or mapcheck to see if key is free command! -buffer -nargs=* BuildTex call BuildTex(0, <f-args>) command! -buffer -nargs=* BuildAndViewTex call BuildTex(1, <f-args>) noremap <buffer> <silent> <F9> <Esc>:call BuildTex(0)<CR> noremap <buffer> <silent> <S-F9> <Esc>:call BuildTex(1)<CR> let b:tex_build_mapped = 1 if exists('g:tex_build_loaded') finish endif let g:tex_build_loaded = 1 function! BuildTex(view_results, ...) write if filereadable("Makefile") " If Makefile is available in current working directory, run 'make' with arguments echo "(using Makefile)" let l:cmd = "!make ".join(a:000, ' ') echo l:cmd execute l:cmd if a:view_results && v:shell_error == 0 call ViewTexResults() endif else let b:tex_flavor = 'pdflatex' compiler tex make % if a:view_results && v:shell_error == 0 call ViewTexResults() endif endif endfunction function! ViewTexResults(...) if a:0 == 0 let l:target = expand("%:p:r") . ".pdf" else let l:target = a:1 endif if has('mac') execute "! open -a Preview ".l:target endif endfunction The problem is that v:shell_error is not set, even if there are compile errors. Any suggestions or insight on how to detect whether a compile was successful or not would be greatly appreciated! Thanks!

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  • MIPS return address in main

    - by Alexander
    I am confused why in the code below I need to decrement the stack pointer and store the return address again. If I don't do that... then PCSpim keeps on looping.. Why is that? ######################################################################################################################## ### main ######################################################################################################################## .text .globl main main: addi $sp, $sp, -4 # Make space on stack sw $ra, 0($sp) # Save return address # Start test 1 ############################################################ la $a0, asize1 # 1st parameter: address of asize1[0] la $a1, frame1 # 2nd parameter: address of frame1[0] la $a2, window1 # 3rd parameter: address of window1[0] jal vbsme # call function # Printing $v0 add $a0, $v0, $zero # Load $v0 for printing li $v0, 1 # Load the system call numbers syscall # Print newline. la $a0, newline # Load value for printing li $v0, 4 # Load the system call numbers syscall # Printing $v1 add $a0, $v1, $zero # Load $v1 for printing li $v0, 1 # Load the system call numbers syscall # Print newline. la $a0, newline # Load value for printing li $v0, 4 # Load the system call numbers syscall # Print newline. la $a0, newline # Load value for printing li $v0, 4 # Load the system call numbers syscall ############################################################ # End of test 1 lw $ra, 0($sp) # Restore return address addi $sp, $sp, 4 # Restore stack pointer jr $ra # Return ######################################################################################################################## ### vbsme ######################################################################################################################## #.text .globl vbsme vbsme: addi $sp, $sp, -4 # create space on the stack pointer sw $ra, 0($sp) # save return address exit: add $v1, $t5, $zero # (v1) x coordinate of the block in the frame with the minimum SAD add $v0, $t4, $zero # (v0) y coordinate of the block in the frame with the minimum SAD lw $ra, 0($sp) # restore return address addi $sp, $sp, 4 # restore stack pointer jr $ra # return If I delete: addi $sp, $sp, -4 # create space on the stack pointer sw $ra, 0($sp) # save return address and lw $ra, 0($sp) # restore return address addi $sp, $sp, 4 # restore stack pointer on vbsme: PCSpim keeps on running... Why??? I shouldn't have to increment/decrement the stack pointer on vbsme and then do the jr again right? The jal in main is supposed to handle that

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  • catching a deadlock in a simple odd-even sending

    - by user562264
    I'm trying to solve a simple problem with MPI, my implementation is MPICH2 and my code is in fortran. I have used the blocking send and receive, the idea is so simple but when I run it it crashes!!! I have absolutely no idea what is wrong? can anyone make quote on this issue please? there is a piece of the code: integer,parameter::IM=100,JM=100 REAL,ALLOCATABLE ::T(:,:),TF(:,:) CALL MPI_COMM_RANK(MPI_COMM_WORLD,RNK,IERR) CALL MPI_COMM_SIZE(MPI_COMM_WORLD,SIZ,IERR) prv = rnk-1 nxt = rnk+1 LIM = INT(IM/SIZ) IF (rnk==0) THEN ALLOCATE(TF(IM,JM)) prv = MPI_PROC_NULL ELSEIF(rnk==siz-1) THEN NXT = MPI_PROC_NULL LIM = LIM+MOD(IM,SIZ) END IF IF (MOD(RNK,2)==0) THEN CALL MPI_SEND(T(2,:),JM+2,MPI_REAL,PRV,10,MPI_COMM_WORLD,IERR) CALL MPI_RECV(T(1,:),JM+2,MPI_REAL,PRV,20,MPI_COMM_WORLD,STAT,IERR) ELSE CALL MPI_RECV(T(LIM+2,:),JM+2,MPI_REAL,NXT,10,MPI_COMM_WORLD,STAT,IERR) CALL MPI_SEND(T(LIM+1,:),JM+2,MPI_REAL,NXT,20,MPI_COMM_WORLD,IERR) END IF as I understood even processes are not receiving anything while the odd ones finish sending successfully, in some cases when I added some print to observe what is going on I saw that the variable NXT is changing during the sending procedure!!! for example all the odd process was sending message to process 0 not their next one!

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  • how to do introspection in R (stat package)

    - by Lebron James
    Hi all, I am somewhat new to R, and i have this piece of code which generates a variable that i don't know the type for. Are there any introspection facility in R which will tell me which type this variable belongs to? The following illustrates the property of this variable: I am working on linear model selection, and the resource I have is lm result from another model. Now I want to retrieve the lm call by the command summary(model)$call so that I don't need to hardcode the model structure. However, since I have to change the dataset, I need to do a bit of modification on the "string", but apparently it is not a simple string. I wonder if there is any command similar to string.replace so that I can manipulate this variable from the variable $call. Thanks > str<-summary(rdnM)$call > str lm(formula = y ~ x1, data = rdndat) > str[1] lm() > str[2] y ~ x1() > str[3] rdndat() > str[3] <- data Warning message: In str[3] <- data : number of items to replace is not a multiple of replacement length > str lm(formula = y ~ x1, data = c(10, 20, 30, 40)) > str<-summary(rdnM)$call > str lm(formula = y ~ x1, data = rdndat) > str[3] <- 'data' > str lm(formula = y ~ x1, data = "data") > str<-summary(rdnM)$call > type str Error: unexpected symbol in "type str" >

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  • RMI no such object in table, Server communication error

    - by ben-casey
    My goal is to create a Distributed computing program that launches a server and client at the same time. I need it to be able to install on a couple of machines and have all the machines communicating with each other, i.e. Master node and 5 slave nodes all from one application. My problem is that I cannot properly use unicastRef, I'm thinking that it is a problem with launching everything on the same port, is there a better way I am overlooking? this is part of my code (the part that matters) try { RMIServer obj = new RMIServer(); obj.start(5225); } catch (Exception e) { e.printStackTrace(); } try { System.out.println("We are slave's "); Registry rr = LocateRegistry.getRegistry("127.0.0.1", Store.PORT, new RClient()); Call ss = (Call) rr.lookup("FILLER"); System.out.println(ss.getHello()); } catch (Exception e) { e.printStackTrace(); } } this is my main class (above) this is the server class (below) public RMIServer() { } public void start(int port) throws Exception { try { Registry registry = LocateRegistry.createRegistry(port, new RClient(), new RServer()); Call stuff = new Call(); registry.bind("FILLER", stuff); System.out.println("Server ready"); } catch (Exception e) { System.err.println("Server exception: " + e.toString()); e.printStackTrace(); } } I don't know what I am missing or what I am overlooking but the output looks like this. Listen on 5225 Listen on 8776 Server ready We are slave's Listen on 8776 java.rmi.NoSuchObjectException: no such object in table at sun.rmi.transport.StreamRemoteCall.exceptionReceivedFromServer(StreamRemoteCall.java:255) at sun.rmi.transport.StreamRemoteCall.executeCall(StreamRemoteCall.java:233) at sun.rmi.server.UnicastRef.invoke(UnicastRef.java:359) at sun.rmi.registry.RegistryImpl_Stub.lookup(Unknown Source) at Main.main(Main.java:62) line 62 is this ::: Call ss = (Call) rr.lookup("FILLER");

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  • video calling (center)

    - by rrejc
    We are starting to develop a new application and I'm searching for information/tips/guides on application architecture. Application should: read the data from an external (USB) device send the data to the remote server (through internet) receive the data from the remote server perform a video call with to the calling (support) center receive a video call call from the calling (support) center support touch screens In addition: some of the data should also be visible through the web page. So I was thinking about: On the server side: use the database (probably MS SQL) use ORM (nHibernate) to map the data from the DB to the domain objects create a layer with business logic in C# create a web (WCF) services (for client application) create an asp.net mvc application (for item 7.) to enable data view through the browser On the client side I would use WPF 4 application which will communicate with external device and the wcf services on the server. So far so good. Now the problem begins. I have no idea how to create a video call (outgoing or incoming) part of the application. I believe that there is no problem to communicate with microphone, speaker, camera with WPF/C#. But how to communicate with the call center? What protocol and encoding should be used? I think that I will need to create some kind of server which will: have a list of operators in the calling center and track which operator is occupied and which operator is free have a list of connected end users receive incoming calls from end users and delegate call to free operator delegate calls from calling center to the end user Any info, link, anything on where to start would be much appreciated. Many thanks!

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  • Vim script to TeX source, and launch PDF only if no errors

    - by Jeet
    Hi, I am switching to using Vim for for my LaTeX editing environment. I would like to be able to tex the source file from within Vim, and launch an external viewing if the compile was successful. I know about the Vim-Latex suite, but, if possible, would prefer to avoid using it: it is pretty heavy-weight, hijacks a lot of my keys, and clutters up my vimruntime with a lot of files. Here is what I have now: if exists('b:tex_build_mapped') finish endif " use maparg or mapcheck to see if key is free command! -buffer -nargs=* BuildTex call BuildTex(0, <f-args>) command! -buffer -nargs=* BuildAndViewTex call BuildTex(1, <f-args>) noremap <buffer> <silent> <F9> <Esc>:call BuildTex(0)<CR> noremap <buffer> <silent> <S-F9> <Esc>:call BuildTex(1)<CR> let b:tex_build_mapped = 1 if exists('g:tex_build_loaded') finish endif let g:tex_build_loaded = 1 function! BuildTex(view_results, ...) write if filereadable("Makefile") " If Makefile is available in current working directory, run 'make' with arguments echo "(using Makefile)" let l:cmd = "!make ".join(a:000, ' ') echo l:cmd execute l:cmd if a:view_results && v:shell_error == 0 call ViewTexResults() endif else let b:tex_flavor = 'pdflatex' compiler tex make % if a:view_results && v:shell_error == 0 call ViewTexResults() endif endif endfunction function! ViewTexResults(...) if a:0 == 0 let l:target = expand("%:p:r") . ".pdf" else let l:target = a:1 endif if has('mac') execute "! open -a Preview ".l:target endif endfunction The problem is that v:shell_error is not set, even if there are compile errors. Any suggestions or insight on how to detect whether a compile was successful or not would be greatly appreciated! Thanks!

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  • Implementing Java Priority Queue

    - by Kay
    public class PriorityQueue<T> { private PriorityNode<T> head, tail; private int numItems; public PriorityQueue(){ numItems = 0; head=null; tail=null; } public void add(int priority, T value){ PriorityNode<T> newNode = new PriorityNode<T>(priority,value); if(numItems == 0){ head = newNode; tail = newNode; } else{ head.setNext(newNode); head = newNode; } } } Where PriorityNode is defined as: public class PriorityNode<T> implements Comparable<T> { private T value; private PriorityNode<T> next; private int priority; public PriorityNode(int priority,T newValue){ value = newValue; next = null; priority = 0; } public PriorityNode(T newValue){ value = newValue; next = null; priority = 0; } public void setPriority(int priority){ this.priority = priority; } public int getPriority(){ return this.priority; } public T getValue(){ return value; } public PriorityNode<T> getNext(){ return next; } public void setNext(PriorityNode<T> nextNode){ this.next = nextNode; } public void setValue(T newValue){ value = newValue; } public int compareTo(int pri) { // TODO Auto-generated method stub if(this.priority<pri){ return -1; } else if(this.priority == pri){ return 0; } else{ return 1; } } } I'm having a lot of difficulty using the Comparator here and implementing a priority queue - please point me in the right direction.

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  • Python subprocess: 64 bit windows server PIPE doesn't exist :(

    - by Spaceman1861
    I have a GUI that launches selected python scripts and runs it in cmd next to the gui window. I am able to get my launcher to work on my (windows xp 32 bit) laptop but when I upload it to the server(64bit windows iss7) I am running into some issues. The script runs, to my knowledge but spits back no information into the cmd window. My script is a bit of a Frankenstein that I have hacked and slashed together to get it to work I am fairly certain that this is a very bad example of the subprocess module. Just wondering if i could get a hand :). My question is how do i have to alter my code to work on a 64bit windows server. :) from Tkinter import * import pickle,subprocess,errno,time,sys,os PIPE = subprocess.PIPE if subprocess.mswindows: from win32file import ReadFile, WriteFile from win32pipe import PeekNamedPipe import msvcrt else: import select import fcntl def recv_some(p, t=.1, e=1, tr=5, stderr=0): if tr < 1: tr = 1 x = time.time()+t y = [] r = '' pr = p.recv if stderr: pr = p.recv_err while time.time() < x or r: r = pr() if r is None: if e: raise Exception(message) else: break elif r: y.append(r) else: time.sleep(max((x-time.time())/tr, 0)) return ''.join(y) def send_all(p, data): while len(data): sent = p.send(data) if sent is None: raise Exception(message) data = buffer(data, sent) The code above isn't mine def Run(): print filebox.get(0) location = filebox.get(0) location = location.__str__().replace(listbox.get(ANCHOR).__str__(),"") theTime = time.asctime(time.localtime(time.time())) lastbox.delete(0, END) lastbox.insert(END,theTime) for line in CookieCont: if listbox.get(ANCHOR) in line and len(line) > 4: line[4] = theTime else: "Fill In the rip Details to record the time" if __name__ == '__main__': if sys.platform == 'win32' or sys.platform == 'win64': shell, commands, tail = ('cmd', ('cd "'+location+'"',listbox.get(ANCHOR).__str__()), '\r\n') else: return "Please use contact admin" a = Popen(shell, stdin=PIPE, stdout=PIPE) print recv_some(a) for cmd in commands: send_all(a, cmd + tail) print recv_some(a) send_all(a, 'exit' + tail) print recv_some(a, e=0) The Code above is mine :)

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  • What is wrong with this recursive Windows CMD script? It won't do Ackermann properly

    - by boost
    I've got this code that I'm trying to get to calculate the Ackermann function so that I can post it up on RosettaCode. It almost works. I thought maybe there'd be a few batch file wizards on StackOverflow. ::echo off set depth=0 :ack if %1==0 goto m0 if %2==0 goto n0 :else set /a n=%2-1 set /a depth+=1 call :ack %1 %n% set t=%errorlevel% set /a depth-=1 set /a m=%1-1 set /a depth+=1 call :ack %m% %t% set t=%errorlevel% set /a depth-=1 if %depth%==0 ( exit %t% ) else ( exit /b %t% ) :m0 set/a n=%2+1 if %depth%==0 ( exit %n% ) else ( exit /b %n% ) :n0 set /a m=%1-1 set /a depth+=1 call :ack %m% %2 set t=%errorlevel% set /a depth-=1 if %depth%==0 ( exit %t% ) else ( exit /b %t% ) I use this script to test it @echo off cmd/c ackermann.cmd %1 %2 echo Ackermann of %1 %2 is %errorlevel% A sample output, for Test 1 1, gives: >test 1 1 >set depth=0 >if 1 == 0 goto m0 >if 1 == 0 goto n0 >set /a n=1-1 >set /a depth+=1 >call :ack 1 0 >if 1 == 0 goto m0 >if 0 == 0 goto n0 >set /a m=1-1 >set /a depth+=1 >call :ack 0 0 >if 0 == 0 goto m0 >set/a n=0+1 >if 2 == 0 (exit 1 ) else (exit /b 1 ) >set t=1 >set /a depth-=1 >if 1 == 0 (exit 1 ) else (exit /b 1 ) >set t=1 >set /a depth-=1 >set /a m=1-1 >set /a depth+=1 >call :ack 0 1 >if 0 == 0 goto m0 >set/a n=1+1 >if 1 == 0 (exit 2 ) else (exit /b 2 ) >set t=2 >set /a depth-=1 >if 0 == 0 (exit 2 ) else (exit /b 2 ) Ackermann of 1 1 is 2

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  • Why is there a time lag when trying to change the text on a button in IE using JQuery?

    - by Deane
    I have some Ajax that runs on a button click. Sometimes it takes a few seconds to return, so I wanted a visual clue to the user that the browser was doing something. So, I have this: $('#SubmitButton').attr("value", "Working..."); $('#SubmitButton').attr("disabled", true); //Synchronous Ajax call goes here $('#SubmitButton').attr("value", "Submit"); $('#SubmitButton').attr("disabled", false); As you can see, it changes the text on the button, and disables it. When the Ajax call comes back (it's synchronous, remember), the button changes back. In Firefox, this works great. In IE, it's...odd. It doesn't run the code in order. It doesn't change the text of the button and launches right into the Ajax call. The browser blocks with the Submit active and saying "Submit." Right after the Ajax comes back, the button quickly flashes "Working..." then back to Submit." So, for some reason, IE isn't changing the text of the button until after the Ajax call, even though the code for it is before the Ajax call. It's acting like this: //Synchronous Ajax call goes here $('#SubmitButton').attr("value", "Working..."); $('#SubmitButton').attr("disabled", true); $('#SubmitButton').attr("value", "Submit"); $('#SubmitButton').attr("disabled", false); Again, this works perfectly in Firefox. But in IE, there's some kind of...lag?

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  • jquery ajaxstart ajaxstop show hide

    - by user1630583
    As usually seemingly simple things take days to resolve, maybe someone could point me to a solution but after 2 days I give up on the following problem; In html, in a form I have a button that is supposed to trigger loading of data through ajax call: <button type="" class="btn" onclick="getData(); return false;">Show Data</button> in javascript: $(document).ajaxStart(function() { $("#qloader").show(); }).ajaxStop(function() { $("#qloader").hide('slow'); });? and in html div with id qloader is defined with 100% width and height and spinner centered as the background, z-index above other: <div id="qloader" class="myLoader" >&nbsp;</div> Now, when page loads, ajax call is executed to get initial data, qloader div is brought up and it shows the spinner - animated, after ajax call finishes, qloader is hidden by ajaxStop. Next, when I click on a button (show data) to initiate another ajax call, ajaxStart is triggered, but it does not show qloader, it waits until ajaxStop is triggered and then in a blink of eye it shows qloader and hides it. I suspected that ajaxStart is not executed, so I put alert before $("#qloader").show(), then alert would be displayed and after that qloader WOULD be displayed BUT spinner animation would be suspended - no spinning, and after ajaxStop it would get hidden. Without alert in ajaxStart trigger, in subsequent ajax calls div is not shown until just before ajaxStop is triggered. It works fine for the first ajax call, but for subsequent ajax call triggered by click on form button it does not work. Any idea what is wrong with this setup?

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  • Same IL code, different output - how is it possible?

    - by Hali
    When I compile this code with mono (gmcs) and run it, it outputs -1 (both with mono and .Net framework). When I compile it with VS (csc), it outputs -1 when I run it with mono, and 0 when I run it with the .Net framework. The code in question is: using System; public class Program { public static void Main() { Console.WriteLine(string.Compare("alo\0alo\0", "alo\0alo\0\0", false, System.Globalization.CultureInfo.InvariantCulture)); } } Compiled with VS: .method public hidebysig static void Main() cil managed { .entrypoint // Code size 29 (0x1d) .maxstack 8 IL_0000: nop IL_0001: ldstr bytearray (61 00 6C 00 6F 00 00 00 61 00 6C 00 6F 00 00 00 ) // a.l.o...a.l.o... IL_0006: ldstr bytearray (61 00 6C 00 6F 00 00 00 61 00 6C 00 6F 00 00 00 // a.l.o...a.l.o... 00 00 ) IL_000b: ldc.i4.0 IL_000c: call class [mscorlib]System.Globalization.CultureInfo [mscorlib]System.Globalization.CultureInfo::get_InvariantCulture() IL_0011: call int32 [mscorlib]System.String::Compare(string, string, bool, class [mscorlib]System.Globalization.CultureInfo) IL_0016: call void [mscorlib]System.Console::WriteLine(int32) IL_001b: nop IL_001c: ret } // end of method Program::Main Compiled with mono: .method public hidebysig static void Main() cil managed { .entrypoint // Code size 27 (0x1b) .maxstack 8 IL_0000: ldstr bytearray (61 00 6C 00 6F 00 00 00 61 00 6C 00 6F 00 00 00 ) // a.l.o...a.l.o... IL_0005: ldstr bytearray (61 00 6C 00 6F 00 00 00 61 00 6C 00 6F 00 00 00 // a.l.o...a.l.o... 00 00 ) IL_000a: ldc.i4.0 IL_000b: call class [mscorlib]System.Globalization.CultureInfo [mscorlib]System.Globalization.CultureInfo::get_InvariantCulture() IL_0010: call int32 [mscorlib]System.String::Compare(string, string, bool, class [mscorlib]System.Globalization.CultureInfo) IL_0015: call void [mscorlib]System.Console::WriteLine(int32) IL_001a: ret } // end of method Program::Main The only difference is the two extra NOP instructions in the VS version. How is it possible?

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