yield

Translation of yield into VB.NET

由 心已入冬 提交于 2019-12-17 20:27:17
问题 first i must assume that i'm not very familiar with the C# yield keyword and its function. What is the best/easiest way to "translate" it into VB.NET? Especially i tried to convert this code into VB.NET, but i failed with: yield return new MatchNode(++index, current.Value); What i have is: Imports System.Collections Imports System.Data.SqlTypes Imports System.Diagnostics.CodeAnalysis Imports System.Text.RegularExpressions Imports Microsoft.SqlServer.Server Class MatchNode Private _index As

Scala - can yield be used multiple times with a for loop?

由 ◇◆丶佛笑我妖孽 提交于 2019-12-17 19:37:31
问题 An example: val l = List(1,2,3) val t = List(-1,-2,-3) Can I do something like this? for (i <- 0 to 10) yield (l(i)) yield (t(i)) Basically I want to yield multiple results for every iteration. 回答1: It's not clear what you're asking for - what you expect the semantics of multiple yield to be. One thing, though, is that you probably never want to use indexes to navigate a list - each call to t(i) is O(i) to execute. So here's one possibility that you might be asking for scala> val l = List(1,2

Iterator pattern in VB.NET (C# would use yield!) [duplicate]

由 爷，独闯天下 提交于 2019-12-17 16:34:09
问题 This question already has answers here : Yield in VB.NET (8 answers) Closed 6 years ago . How do implement the iterator pattern in VB.NET, which does not have the yield keyword? 回答1: This is now supported in VS 2010 SP1, with the Async CTP, see: Iterators (C# and Visual Basic) on MSDN and download Visual Studio Async CTP (Version 3). Code such as this, works: Private Iterator Function SomeNumbers() As IEnumerable ' Use multiple yield statements. Yield 3 Yield 5 Yield 8 End Function 回答2: VB

Passing multiple code blocks as arguments in Ruby

由 旧城冷巷雨未停 提交于 2019-12-17 16:05:12
问题 I have a method which takes a code block. def opportunity @opportunities += 1 if yield @performances +=1 end end and I call it like this: opportunity { @some_array.empty? } But how do I pass it more than one code block so that I could use yield twice, something like this: def opportunity if yield_1 @opportunities += 1 end if yield_2 @performances +=1 end end and: opportunity {@some_other_array.empty?} { @some_array.empty? } I am aware that this example could be done without yield, but it's

What is the result of a yield expression in Python?

由 夙愿已清 提交于 2019-12-17 15:32:27
问题 I know that yield turns a function into a generator, but what is the return value of the yield expression itself? For example: def whizbang(): for i in range(10): x = yield i What is the value of variable x as this function executes? I've read the Python documentation: http://docs.python.org/reference/simple_stmts.html#grammar-token-yield_stmt and there seems to be no mention of the value of the yield expression itself. 回答1: You can also send values to generators. If no value is sent then x

What happens when promise is yielded in javascript?

由 半城伤御伤魂 提交于 2019-12-17 13:22:58
问题 Didn't find full answer .. What happens when promise is yielded? Is such construction var p = new Promise() p.resolve(value) function * (){ yield p } equivalent to function * (){ yield value } ? UPDATE How to mix different styles of async programming, for example for such framework as koa? Koa middlewares are working with generators, but there are lots of good packages which are promise-based (sequelize for ex.) 回答1: As Felix says, a promise is just another value to be yielded. However, there

Converting “yield from” statement to Python 2.7 code

由 白昼怎懂夜的黑 提交于 2019-12-17 02:47:27
问题 I had a code below in Python 3.2 and I wanted to run it in Python 2.7. I did convert it (have put the code of missing_elements in both versions) but I am not sure if that is the most efficient way to do it. Basically what happens if there are two yield from calls like below in upper half and lower half in missing_element function? Are the entries from the two halves (upper and lower) appended to each other in one list so that the parent recursion function with the yield from call and use both

Resetting generator object in Python

由 梦想的初衷 提交于 2019-12-17 02:09:30
问题 I have generator object returned by multiple yield. Preparation to call this generator is rather time-consuming operation. That is why I want to reuse generator several times. y = FunctionWithYield() for x in y: print(x) #here must be something to reset 'y' for x in y: print(x) Of course, I'm taking in mind copying content into simple list. 回答1: Another option is to use the itertools.tee() function to create a second version of your generator: y = FunctionWithYield() y, y_backup = tee(y) for

理解PHP中的Generator

由 ♀尐吖头ヾ 提交于 2019-12-17 01:42:56
PHP中Generator，似乎是在5.5版中引入了。 PHP中的协程必须依赖于Generator来实现，所以我觉得有必要先专门写一篇文章介绍Generator。 Generator这个单词在这里对应的中文词语应该是“生成器”，在编程这个领域，我们可以把它想象成一个可以生成一系列数据的工具，这个工具可以具体为一个类、一个函数或者是一个语句（由特殊的关键字构成），而且事实上也确实如此。在PHP中Generator是由函数生成的，但这个函数又跟普通的函数不同，具体有什么不同等会会慢慢道来。 我们先介绍Generator的另外一个特点，这个特点也是 php的官方文档 介绍Generator的第一句话：Generator提供了一种方便的实现简单的Iterator（迭代器）的方式，使用Generator实现Iterator不需要创建一个类来继承Iterator接口。 Iterator接口 所以如果想搞清楚Generator，需要先了解Iterator接口。我们通常使用foreach对数组进行遍历，如果要对对象进行遍历，那么这个对象的类就必须实现 Iterator 接口，并且实现Iterator接口所提供的5个方法： Iterator extends Traversable { /* Methods */ abstract public mixed current ( void ) /

多线程基础知识

由 亡梦爱人 提交于 2019-12-16 22:07:40
线程与进程的区别 　　1. 进程是资源分配的最小单元，线程是CPU调度的最小单元。所有与进程相关的资源，均被记录再PCB中。 　　2. 线程隶属于某一个进程，共享所有进程的资源。线程只由堆栈寄存器、程序计数器和TCB构成。 　　3. 进程可以看作独立的应用，线程不能看作独立的应用。 　　4. 进程有独立的地址空间，相互不影响，而线程只是进程的不同执行路径，如果线程挂了，进程也就挂了。所以多进程的程序比多线程程序健壮，但是切换消耗资源多。 　　 Java中进程与线程的关系 　　1. 运行一个程序会产生一个进程，进程至少包含一个线程。 　　2. 每个进程对应一个JVM实例，多线线程共享JVM中的堆。 　　3. Java采用单线程编程模型，程序会自动创建主线程。 　　4. 主线程可以创建子线程，原则上要后于子线程完成执行。 线程中start方法和run方法的区别 　　Java中创建线程的方式有两种，不管使用继承Thread的方法是hiRunnable接口的方法，都需要重写run方法。调用start方法会创建一个新的线程并启动，run方法只是启动线程后的回调函数，如果调用run方法，那么执行run方法的线程不会是新创建的线程，而如果使用start方法，那么执行run方法的线程就是我们刚刚启动的那个线程。 public class Main { public static void main
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