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What's your take on this Javascript thingy?

- by Nischal

We've been having a discussion at our workplace on this with some for and some against the behavior. Wanted to hear views from you guys : <html> <body> <div> Test! <script> document.body.removeChild(document.getElementsByTagName('div')[0]); </script> </div> </body> </html> Should the above script work and do what it's supposed to do? First, let's see what's happening here : I have a javascript that's inside the <div> element. This javascript will delete the child node within body which happens to hold the div inside which the script itself exists. Now, the above script works fine in Firefox, Opera and IE8. But IE6 and IE7 give an alert saying they cannot open the page. Let's not debate on how IE should have handled this (they've accepted it as a bug and hence fixed it in IE8). The point here is since the 'SCRIPT' tag itself is a part of DOM, should it be allowed to do something like this? Should it even exist after such an operation?

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Java: How ArrayList memory management

- by cka3o4nik

In my Data Structures class we have studies the Java ArrayList class, and how it grows the underlying array when a user adds more elements. That is understood. However, I cannot figure out how exactly this class frees up memory when lots of elements are removed from the list. Looking at the source, there are three methods that remove elements: [code] public E remove(int index) { RangeCheck(index); modCount++; E oldValue = (E) elementData[index]; int numMoved = size - index - 1; if (numMoved 0) System.arraycopy(elementData, index+1, elementData, index, numMoved); elementData[--size] = null; // Let gc do its work return oldValue; } public boolean remove(Object o) { if (o == null) { for (int index = 0; index < size; index++) if (elementData[index] == null) { fastRemove(index); return true; } } else { for (int index = 0; index < size; index++) if (o.equals(elementData[index])) { fastRemove(index); return true; } } return false; } private void fastRemove(int index) { modCount++; int numMoved = size - index - 1; if (numMoved 0) System.arraycopy(elementData, index+1, elementData, index, numMoved); elementData[--size] = null; // Let gc do its work } {/code] None of them reduce the datastore array. I even started questioning if memory free up ever happens, but empirical tests show that it does. So there must be some other way it is done, but where and how? I checked the parent classes as well with no success.

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How to parse a string (by a "new" markup) with R ?

- by Tal Galili

Hi all, I want to use R to do string parsing that (I think) is like a simplistic HTML parsing. For example, let's say we have the following two variables: Seq <- "GCCTCGATAGCTCAGTTGGGAGAGCGTACGACTGAAGATCGTAAGGtCACCAGTTCGATCCTGGTTCGGGGCA" Str <- ">>>>>>>..>>>>........<<<<.>>>>>.......<<<<<.....>>>>>.......<<<<<<<<<<<<." Say that I want to parse "Seq" According to "Str", by using the legend here Seq: GCCTCGATAGCTCAGTTGGGAGAGCGTACGACTGAAGATCGTAAGGtCACCAGTTCGATCCTGGTTCGGGGCA Str: >>>>>>>..>>>>........<<<<.>>>>>.......<<<<<.....>>>>>.......<<<<<<<<<<<<. | | | | | | | || | +-----+ +--------------+ +---------------+ +---------------++-----+ | Stem 1 Stem 2 Stem 3 | | | +----------------------------------------------------------------+ Stem 0 Assume that we always have 4 stems (0 to 3), but that the length of letters before and after each of them can very. The output should be something like the following list structure: list( "Stem 0 opening" = "GCCTCGA", "before Stem 1" = "TA", "Stem 1" = list(opening = "GCTC", inside = "AGTTGGGA", closing = "GAGC" ), "between Stem 1 and 2" = "G", "Stem 2" = list(opening = "TACGA", inside = "CTGAAGA", closing = "TCGTA" ), "between Stem 2 and 3" = "AGGtC", "Stem 3" = list(opening = "ACCAG", inside = "TTCGATC", closing = "CTGGT" ), "After Stem 3" = "", "Stem 0 closing" = "TCGGGGC" ) I don't have any experience with programming a parser, and would like advices as to what strategy to use when programming something like this (and any recommended R commands to use). What I was thinking of is to first get rid of the "Stem 0", then go through the inner string with a recursive function (let's call it "seperate.stem") that each time will split the string into: 1. before stem 2. opening stem 3. inside stem 4. closing stem 5. after stem Where the "after stem" will then be recursively entered into the same function ("seperate.stem") The thing is that I am not sure how to try and do this coding without using a loop. Any advices will be most welcomed.

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Can a member struct be zero-init from the constructor initializer list without calling memset?

- by selbie

Let's say I have the following structure declaration (simple struct with no constructor). struct Foo { int x; int y; int z; char szData[DATA_SIZE]; }; Now let's say this struct is a member of a C++ class as follows: class CFoobar { Foo _foo; public: CFoobar(); }; If I declare CFoobar's constructor as follows: CFoobar::CFoobar() { printf("_foo = {%d, %d, %d}\n", _foo.x, _foo.y,_foo.z); for (int x = 0; x < 100; x++) printf("%d\n", _foo.szData[x]); } As you would expect, when CFoobar's constructor runs, garbage data gets printed out Obviously, the easy fix is to memset or ZeroMemory &_foo. It's what I've always done... However, I did notice that if add _foo to the constructor's initialization list with no parameters as follows: CFoobar::CFoobar() : _foo() { That this appears to zero-out the member variables of _foo. At least that was the case with g++ on linux. Now here's my question: Is this standard C++, or is this compiler specific behavior? If it's standard behavior, can someone quote me a reference from an official source? Any "gotchas" in regards to implicit zero-init behavior with more complicated structs and classes?

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recursive wget with hotlinked requisites

- by dongle

I often use wget to mirror very large websites. Sites that contain hotlinked content (be it images, video, css, js) pose a problem, as I seem unable to specify that I would like wget to grab page requisites that are on other hosts, without having the crawl also follow hyperlinks to other hosts. For example, let's look at this page https://dl.dropbox.com/u/11471672/wget-all-the-things.html Let's pretend that this is a large site that I would like to completely mirror, including all page requisites – including those that are hotlinked. wget -e robots=off -r -l inf -pk ^^ gets everything but the hotlinked image wget -e robots=off -r -l inf -pk -H ^^ gets everything, including hotlinked image, but goes wildly out of control, proceeding to download the entire web wget -e robots=off -r -l inf -pk -H --ignore-tags=a ^^ gets the first page, including both hotlinked and local image, does not follow the hyperlink to the site outside of scope, but obviously also does not follow the hyperlink to the next page of the site. I know that there are various other tools and methods of accomplishing this (HTTrack and Heritrix allow for the user to make a distinction between hotlinked content on other hosts vs hyperlinks to other hosts) but I'd like to see if this is possible with wget. Ideally this would not be done in post-processing, as I would like the external content, requests, and headers to be included in the WARC file I'm outputting.

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Should I learn two (or more) programming languages in parallel?

- by c_maker

I found entries on this site about learning a new programming language, however, I have not come across anything that talks about the advantages and disadvantages of learning two languages at the same time. Let's say my goal is to learn two new languages in a year. I understand that the definition of learning a new language is different for everyone and you can probably never know everything about a language. I believe in most cases the following things are enough to include the language in your resume and say that you are proficient in it (list is not in any particular order): Know its syntax so you can write a simple program in it Compare its underlying concepts with concepts of other languages Know best practices Know what libraries are available Know in what situations to use it Understand the flow of a more complex program At least know most of what you do not know I would probably look for a good book and pick an open source project for both of these languages to start with. My questions: Is it best to spend 5 months learning language#1 then 5 months learning language#2, or should you mix the two. Mixing them I mean you work on them in parallel. Should you pick two languages that are similar or different? Are there any advantages/disadvantages of let's say learning Lisp in tandem with Ruby? Is it a good idea to pick two languages with similar syntax or would it be too confusing? Please tell me what your experiences are regarding this. Does it make a difference if you are a beginner or a senior programmer?

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Determining an object's variable name dynamically?

- by ZenBlender

Let's say I have some objects: ArrayList<SomeObject> list = new ArrayList<SomeObject>(); SomeObject A = new SomeObject(); SomeObject B = new SomeObject(); SomeObject C = new SomeObject(); SomeObject D = new SomeObject(); These constructors automatically add each object to the ArrayList so I can iterate over them but still maintain the variable names for direct access: public SomeObject(){ // init stuff here list.add(this); } But then, let's say I want to output some debug info, and iterate through list and print out the NAME of each object? How can I do that? Essentially, when "SomeObject A = new SomeObject();" is executed, I want to use reflection (if possible) to determine that this variable's name is "A" (a String) and either store that in the object when the constructor executes, or determine it dynamically through reflection when referencing this object with the variable named "A". Does that make sense? How can I do this? Thanks!

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XCode Obj-C: Make new NSArray from one key each out of an Array of Dictionaries

- by user323772

This actually could be a multipart question. But here's the first part ... I have an array (actually in a plist) of dictionaries. Each dictionary has 3 keys in it: (title), (points), and (description). I am trying to make a NEW array with the values of the key "title" from each dictionary in that first array. Let me explain WHY I am doing this and maybe that will provide a better all around explanation. I am trying to let people pick from a pre-determined list. Heck, if this was a web page it would be very simple since all I really care about are the "points" and the "Title". On a web site I could simply do a drop down combo-box with the "points" being the value and the title being the text for each row. But this is not a web page. So what I am trying to do here is pop out a modal picker when they click the text field. The modal picker shows the alphabetical ordered "titles" from our new array. And whichever one they select, it closes the modal view and assigns that "title" text to the UITextField which cannot be edited by the user. I have some code to get my modal picker to pop out. But I need to feed it an array of just the "titles" of each dictionary in my real array. Thanks in advance (and yes I am a newbie)

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Haskell: How to compose `not` with a function of arbitrary arity?

- by Hynek -Pichi- Vychodil

When I have some function of type like f :: (Ord a) => a -> a -> Bool f a b = a > b I should like make function which wrap this function with not. e.g. make function like this g :: (Ord a) => a -> a -> Bool g a b = not $ f a b I can make combinator like n f = (\a -> \b -> not $ f a b) But I don't know how. *Main> let n f = (\a -> \b -> not $ f a b) n :: (t -> t1 -> Bool) -> t -> t1 -> Bool Main> :t n f n f :: (Ord t) => t -> t -> Bool *Main> let g = n f g :: () -> () -> Bool What am I doing wrong? And bonus question how I can do this for function with more and lest parameters e.g. t -> Bool t -> t1 -> Bool t -> t1 -> t2 -> Bool t -> t1 -> t2 -> t3 -> Bool

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How to access parents' members from a inner class in WPF?

- by black sensei

Hello Experts! I'm trying to do scheduled operation let's say to check for user's credit left via web service call and update the user interface. i've tried with quartz.net to implement the scheduling bit.i created an inner class in the window class i need to update.That inner class has the method that calls the webservice and the result needs to be displayed back to the UI. here is an example of what i did. public partial class Window2 : Window { private int i; public Window2() { InitializeComponent(); } public class Myclass :IJob { public void Execute(JobExecutionContext context) { string result = doMyOperation(); //i'll like to call parent label member of name lblNotif //is something like parent.lblNotif.Content = result; //possible? } public string doMyOperation() { //calling the wermethod to retreive user's balance return result = service.GetUsersBalace(user); } } } Well the quartz bit is working and this post is not about quartz. here are my questions Question 1 : How is it possible to access Window2 controls, for instace lable lblNotif? Question 2 : If my thinking about this is wrong, what is done as best practice to solve my kind of problem, where an application need to do an operation let's say every 5mn and update the the UI. Question 3 : i at first tried to use the backgroundworker and i felt like i can't do the scheduling bit with it.Is that correct or i'm wrong. thanks for those who commented already and sorry for those who didn't get the meaning of my post.I hope this will be a bit clearer.Thanks for reading

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C++: Vector of objects vs. vector of pointers to new objects?

- by metamemetics

Hello, I am seeking to improve my C++ skills by writing a sample software renderer. It takes objects consisting of points in a 3d space and maps them to a 2d viewport and draws circles of varying size for each point in view. Which is better: class World{ vector<ObjectBaseClass> object_list; public: void generate(){ object_list.clear(); object_list.push_back(DerivedClass1()); object_list.push_back(DerivedClass2()); or... class World{ vector<ObjectBaseClass*> object_list; public: void generate(){ object_list.clear(); object_list.push_back(new DerivedClass1()); object_list.push_back(new DerivedClass2()); ?? Would be using pointers in the 2nd example to create new objects defeat the point of using vectors, because vectors automatically call the DerivedClass destructors in the first example but not in the 2nd? Are pointers to new objects necessary when using vectors because they handle memory management themselves as long as you use their access methods? Now let's say I have another method in world: void drawfrom(Viewport& view){ for (unsigned int i=0;i<object_list.size();++i){ object_list.at(i).draw(view); } } When called this will run the draw method for every object in the world list. Let's say I want derived classes to be able to have their own versions of draw(). Would the list need to be of pointers then in order to use the method selector (-) ?

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C++ - Where to throw exception?

- by HardCoder1986

Hello! I have some kind of an ideological question, so: Suppose I have some templated function template <typename Stream> void Foo(Stream& stream, Object& object) { ... } which does something with this object and the stream (for example, serializes that object to the stream or something like that). Let's say I also add some plain wrappers like (and let's say the number of these wrappers equals 2 or 3): void FooToFile(const std::string& filename, Object& object) { std::ifstream stream(filename.c_str()); Foo(stream, object); } So, my question is: Where in this case (ideologically) should I throw the exception if my stream is bad? Should I do this in each wrapper or just move that check to my Foo, so that it's body would look like if (!foo.good()) throw (something); // Perform ordinary actions I understand that this may be not the most important part of coding and these solutions are actually equal, but I just wan't to know "the proper" way to implement this. Thank you.

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How can I bind the same dependency to many dependents in Ninject?

- by Mike Bantegui

Let's I have three interfaces: IFoo, IBar, IBaz. I also have the classes Foo, Bar, and Baz that are the respective implementations. In the implementations, each depends on the interface IContainer. So for the Foo (and similarly for Bar and Baz) the implementation might read: class Foo : IFoo { private readonly IDependency Dependency; public Foo(IDependency dependency) { Dependency = dependency; } public void Execute() { Console.WriteLine("I'm using {0}", Dependency.Name); } } Let's furthermore say I have a class Container which happens to contain instances of the IFoo, IBar and IBaz: class Container : IContainer { private readonly IFoo _Foo; private readonly IBar _Bar; private readonly IBaz _Baz; public Container(IFoo foo, IBar bar, IBaz baz) { _Foo = foo; _Bar = bar; _Baz = baz; } } In this scenario, I would like the implementation class Container to bind against IContainer with the constraint that the IDependency that gets injected into IFoo, IBar, and IBaz be the same for all three. In the manual way, I might implement it as: IDependency dependency = new Dependency(); IFoo foo = new Foo(dependency); IBar bar = new Bar(dependency); IBaz baz = new Baz(dependency); IContainer container = new Container(foo, bar, baz); How can I achieve this within Ninject? Note: I am not asking how to do nested dependencies. My question is how I can guarantee that a given dependency is the same among a collection of objects within a materialized service. To be extremely explicit, I understand that Ninject in it's standard form will generate code that is equivalent to the following: IContainer container = new Container(new Foo(new Dependency()), new Bar(new Dependency()), new Baz(new Dependency())); I would not like that behavior.

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Database tables with dynamic information

- by Tim Fennis

I've googled this and found that it's almost impossible to create a database with dynamic collumns. I'll explain my problem first. I am making a webshop for a customer. It has multiple computer products for sale. CPU's HDD's RAM ect. All these products have different properties, a CPU has an FSB, RAM has a CAS latency. But this is very inconvenient because my orders table needs foreign keys to different tables which is impossible. An other option is to store all the product specific information in a varchar or blob field and let PHP figure it out. The problem with this solution is that the website needs a PC builder. A step-by-step guide to building your PC. So for instance if a customer decides he wants a new "i7 920" or whatever i want to be able to sellect all motherboards for socket 1366, which is impossible because all the data is stored in one field. I know it's possible to select all motherboards form the DB and let PHP figure out which ones are for socket 1366 but i was wondering, is there a better solution?

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Should a "script" tag be allowed to remove itself?

- by Nischal

We've been having a discussion at our workplace on this with some for and some against the behavior. Wanted to hear views from you guys : <html> <body> <div> Test! <script> document.body.removeChild(document.getElementsByTagName('div')[0]); </script> </div> </body> </html> Should the above script work and do what it's supposed to do? First, let's see what's happening here : I have a javascript that's inside the <div> element. This javascript will delete the child node within body which happens to hold the div inside which the script itself exists. Now, the above script works fine in Firefox, Opera and IE8. But IE6 and IE7 give an alert saying they cannot open the page. Let's not debate on how IE should have handled this (they've accepted it as a bug and hence fixed it in IE8). The point here is since the 'SCRIPT' tag itself is a part of DOM, should it be allowed to do something like this? Should it even exist after such an operation? Edit: Firefox, Opera, IE9 etc. do not remove the 'script' tag if I run the above code. But, document.getElementsByTagName('script').length returns 0! To understand what I mean, add alert(document.getElementsByTagName('script').length); before and after document.body.removeChild(document.getElementsByTagName('div')[0]); in the code above.

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Generic file container for quick read of data

- by DreamCodeR

Since there are some major privacy issues with alot of social networking sites I am trying to think about alternatives. One is to let the user keep all the information stored in some kind of file container. Now, I haven't found a single type of container that can hold "generic" information. Only for audio/video. What I want is a container that can be read by PHP with some kind of index file that lists up the users pictures in a image/ directory in the container, FOAF files (or some alternative XML-file describing users information and friends, etc.). My thoughts was to let the user keep all their information and data stored in a container that can be imported/exported and deleted from my server (the prototype social networking site I am trying to create), and then uploaded to another site that might use the same format (not that I think that will ever happen, but the user still keeps all their pictures, data, comments, messages, etc). The only thing I have come up with yet is to create a tar archive with the Archive_tar library which extracts and creates Tar-archives with an index-file describing which files are holding the messages (there might be several so each file won't be so large), what pictures are in the image/ folder and what are their names and what comments they have gotten etc. Maybe also the permissions for viewing each type of content. Does there exist any generic file format of a container that I can use to keep all this information in one file with a tree-like index file? Or must i try and create something like this myself?

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Clustered Graphs Visualization Techniques

- by jameszhao00

I need to visualize a relatively large graph (6K nodes, 8K edges) that has the following properties: Distinct Clusters. Approximately 50-100 Nodes per cluster and moderate interconnectivity at the cluster level Minimal (5-10 inter-cluster edges per cluster) interconnectivity between clusters Let global edge overlap = The edge overlaps caused by directly visualizing a graph of Clusters = {A, B, C, D, E}, Edges = {Pentagram of those clusters, which is non-planar by the way and will definitely generate edge overlap if you draw it out directly} Let Local Edge Overlap = the above but { A, B, C, D, E } are just nodes. I need to visualize graphs with the above in a way that satisfies the following requirements No global edge overlap (i.e. edge overlaps caused by inter-cluster properties is not okay) Local edge overlap within a cluster is fine Anyone have thoughts on how to best visualize a graph with the requirements above? One solution I've come up with to deal with the global edge overlap is to make sure a cluster A can only have a max of 1 direct edge to another cluster (B) during visualization. Any additional inter-cluster edges between cluster A - C, A - D, ... are disconnected and additional node/edges A - A_C, C - C_A, A - A_D, D - D_A... are created. Anyone have any thoughts?

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memcached: which is faster, doing an add (and checking result), or doing a get (and set when returni

- by Mike Sherov

The title of this question isn't so clear, but the code and question is straightforward. Let's say I want to show my users an ad once per day. To accomplish this, every time they visit a page on my site, I check to see if a certain memcache key has any data stored on it. If so, don't show an ad. If not, store the value '1' in that key with an expiration of 86400. I can do this 2 ways: //version a $key='OPD_'.date('Ymd').'_'.$type.'_'.$user; if($memcache->get($key)===false){ $memcache->set($key,'1',false,$expire); //show ad } //version b $key='OPD_'.date('Ymd').'_'.$type.'_'.$user; if($memcache->add($key,'1',false,$expire)){ //show ad } Now, it might seem obvious that b is better, it always makes 1 memcache call. However, what is the overhead of "add" vs. "get"? These aren't the real comparisons... and I just made up these numbers, but let's say 1 add ~= 1 set ~= 5 get in terms of effort, and the average user views 5 pages a day: a: (5 get * 1 effort) + (1 set * 5 effort) = 10 units of effort b: (5 add * 5 effort) = 25 units of effort Would it make sense to always do the add call? Is this an unnecessary micro-optimization?

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How can I provide property-level string formatting?

- by jhubsharp

Not sure if the question wording is accurate, but here's what I want to do: I want to databind a class with some strings in it: class MyClass { public string MyProperty { get; set; } public string MyProperty2 { get; set; } } When databinding, everything behaves normally. On the back end, I'm writing to a file and I want MyProperty2 to always be encrypted using some encryption algorithm. I want my back-end code to write each string without needing to know that encryption is required (I want the class to know it should be encrypted, not the consumer). Can I do this with a type converter, or something similar? EDIT: There are other scenarios as well. Some booleans I want to format as "Y" or "N", other booleans I want formatted as "Enabled" / "Disabled", etc. I can write (and have written) helper methods and let the file writer call the helper methods as appropriate, I'm just wondering if there's a way to do this without the file writer needing to know which objects need which kind of formatting and let the objects tell that to the file writer.

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How should a multi-threaded C application handle a failed malloc()?

- by user294463

A part of an application I'm working on is a simple pthread-based server that communicates over a TCP/IP socket. I am writing it in C because it's going to be running in a memory constrained environment. My question is: what should the program do if one of the threads encounters a malloc() that returns NULL? Possibilities I've come up with so far: No special handling. Let malloc() return NULL and let it be dereferenced so that the whole thing segfaults. Exit immediately on a failed malloc(), by calling abort() or exit(-1). Assume that the environment will clean everything up. Jump out of the main event loop and attempt to pthread_join() all the threads, then shut down. The first option is obviously the easiest, but seems very wrong. The second one also seems wrong since I don't know exactly what will happen. The third option seems tempting except for two issues: first, all of the threads need not be joined back to the main thread under normal circumstances and second, in order to complete the thread execution, most of the remaining threads will have to call malloc() again anyway. What shall I do?

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QLearning and never-ending episodes

- by devoured elysium

Let's imagine we have an (x,y) plane where a robot can move. Now we define the middle of our world as the goal state, which means that we are going to give a reward of 100 to our robot once it reaches that state. Now, let's say that there are 4 states(which I will call A,B,C,D) that can lead to the goal state. The first time we are in A and go to the goal state, we will update our QValues table as following: Q(state = A, action = going to goal state) = 100 + 0 One of 2 things can happen. I can end the episode here, and start a different one where the robot has to find again the goal state, or I can continue exploring the world even after I found the goal state. If I try to do this, I see a problem though. If I am in the goal state and go back to state A, it's Qvalue will be the following: Q(state = goalState, action = going to A) = 0 + gamma * 100 Now, if I try to go again to the goal state from A: Q(state = A, action = going to goal state) = 100 + gamma * (gamma * 100) Which means that if I keep doing this, as 0 <= gamma <= 0, both qValues are going to rise forever. Is this the expected behavior of QLearning? Am I doing something wrong? If this is the expected behavior, can't this lead to problems? I know that probabilistically, all the 4 states(A,B,C and D), will grow at the same rate, but even so it kinda bugs me having them growing forever. The ideia of allowing the agent to continue exploring even after finding the goal has to do with that the nearer he is from the goal state, the more likely it is to being in states that can be updated at the moment.

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What guarantees are there on the run-time complexity (Big-O) of LINQ methods?

- by tzaman

I've recently started using LINQ quite a bit, and I haven't really seen any mention of run-time complexity for any of the LINQ methods. Obviously, there are many factors at play here, so let's restrict the discussion to the plain IEnumerable LINQ-to-Objects provider. Further, let's assume that any Func passed in as a selector / mutator / etc. is a cheap O(1) operation. It seems obvious that all the single-pass operations (Select, Where, Count, Take/Skip, Any/All, etc.) will be O(n), since they only need to walk the sequence once; although even this is subject to laziness. Things are murkier for the more complex operations; the set-like operators (Union, Distinct, Except, etc.) work using GetHashCode by default (afaik), so it seems reasonable to assume they're using a hash-table internally, making these operations O(n) as well, in general. What about the versions that use an IEqualityComparer? OrderBy would need a sort, so most likely we're looking at O(n log n). What if it's already sorted? How about if I say OrderBy().ThenBy() and provide the same key to both? I could see GroupBy (and Join) using either sorting, or hashing. Which is it? Contains would be O(n) on a List, but O(1) on a HashSet - does LINQ check the underlying container to see if it can speed things up? And the real question - so far, I've been taking it on faith that the operations are performant. However, can I bank on that? STL containers, for example, clearly specify the complexity of every operation. Are there any similar guarantees on LINQ performance in the .NET library specification?

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Generic list/sublist handling

- by user628661

Let's say we have a class class ComplexCls { public int Fld1; public string Fld2; //could be more fields } class Cls { public int SomeField; } and then some code class ComplexClsList: List<ComplexCls>; ComplexClsList myComplexList; // fill myComplexList // same for Cls class ClsList : List<Cls>; ClsList myClsList; We want to populate myClsList from myComplexList, something like (pseudocode): foreach Complexitem in myComplexList { Cls ClsItem = new Cls(); ClsItem.SomeField = ComplexItem.Fld1; } The code to do this is easy and will be put in some method in myClsList. However I'd like to design this as generic as possible, for generic ComplexCls. Note that the exact ComplexCls is known at the moment of using this code, only the algorithm shd be generic. I know it can be done using (direct) reflection but is there other solution? Let me know if the question is not clear enough. (probably isn't). [EDIT] Basically, what I need is this: having myClsList, I need to specify a DataSource (ComplexClsList) and a field from that DataSource (Fld1) that will be used to populate my SomeField

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SAS V9.1.3 - Error when combining %INC and CALL EXECUTE

- by Mark

Hi, I am getting a resolution error with some SAS v9.1.3 code. Here is some code I want to store in a .txt file (called problem2.txt) and bring into SAS with a %INC %macro email020; %if &email = 1 %then %do; %put THIS RESOLVED AT 1; %end; %else %if &email = 2 %then %do; %put THIS RESOVLED AT 2; %end; %put _user_; %mend email020; %email020; Then this is the main code: filename problem2 'C:\Documents and Settings\Mark\My Documents\problem2.txt'; %macro report1; %let email = 1; %inc problem2; %mend report1; %macro report2 (inc); %let email = 2; %inc problem2; %mend report2; data test; run = 'YES'; run; data _null_; set test; call execute("%report1"); call execute("%report2"); run; The log shows: NOTE: CALL EXECUTE generated line. 1 + %inc problem2; MLOGIC(EMAIL020): Beginning execution. WARNING: Apparent symbolic reference EMAIL not resolved. ERROR: A character operand was found in the %EVAL function or %IF condition where a numeric operand is required. The condition was: &email = 1 ERROR: The macro EMAIL020 will stop executing. MLOGIC(EMAIL020): Ending execution. So the question is why does CALL EXECUTE generate %inc problem2 rather than %report1, causing SAS to miss the assignment and what can I do about it?

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Set tier price on different products (special conditions) in Magento?

- by user1547625

Let’s say I sell mobile phones. I might sell phones with the following tiered pricing iPhone4 (1x$200ea. 3x$150ea. 10x$100ea.) iPhone4s (1x$300ea. 3x$250ea. 10x$200ea.) iPhone5 (1x$500ea. 3x$400ea. 10x$1300ea.) Plus maybe I sell Samsungs, Nokias, accessories, etc. So let’s say a customer wants to buy 3 iphones, but they want 1x iPhone 4, 1x iPhone 4s and 1x iPhone 5. Instead of getting the single unit price for each, we would want to group iphones, so that they would get the 3x price for each unit. So they would spend $150 on the iPhone 4, $250 on the iPhone 4s and $400 on the iPhone 5.... We’d have several categories and could create some type of spreadsheet for you, but would want to also have the ability to set up this categorization in the future. So please tell me how to get this done from magento admin or any other way?

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