reflex

C++ 实现反射机制

纵饮孤独 提交于 2020-10-29 13:30:56
C++ 实现反射机制 C++ 实现反射机制 一.前言: JAVA有着一个非常突出的动态相关机制:Reflection,用在Java身上指的是我们可以于运行时加载、探知、使用编译期间完全未知的classes。换句话说,Java程序可以加载一个运行时才得知名称的class,获悉其完整构造(但不包括methods定义),并生成其对象实体、或对其fields设值、或唤起其methods。然而C ++是不支持反射机制,虽然C++有RTTI(运行时类型识别)。但是想要实现C++ 对象序列化,序列化就是存储到磁盘上,将对象变成一定格式的二进制编码,然后要用的时候再将保存在磁盘上的二进制编码转化成一个内存中的对象,这个过程中总是需要有一个指示来告诉编译器要生成什么样的对象,最简单的方式当然就是类名了,例如:将一个ClassXXX对象存储到磁盘上,再从磁盘读取的时候让编译器根据“ClassXXX”名称来new一个对象。 ClassT * obj = FactoryCreate( " ClassT " ); 类似于以上的语法,虽然C ++没有自带的语法可以实现,但是我们可以自己通过其他方法来实现。(由于本人能力有限,所以该篇博客只是讲解如何简单的实现这个反射机制,而对C++ 中拥有这个反射机制是否有必要不做任何讨论。当然,如果博客中有什么地方说的有错误还望大家可以在下面评论指出谢谢) 二.实现: 1

Geek的办公桌长什么样?

懵懂的女人 提交于 2020-08-06 19:54:12
每当有人看到我的办公桌时,总少不了问关于我“特有”的键盘设置的问题。然后就有人建议我花些时间来分享一下我多年来收集的各种可以有效提高工作效率的Geek产品/技巧。因此,也就有了下面的这一整张列表:这些产品和工具可帮助我在公司和在家中都能持续保持高效的生产力。 这里的大多数技巧都是比较个人向的。如果你像我一样,一天中的大部分时间内都在使用计算机,那你工作区域的布置就显得尤为重要了。 请不要直接抱着你的笔记本电脑工作。 我在阿姆斯特丹Uber的办公桌 1. MacBook Pro 我的这台笔记本电脑是我老板给我的。两年前我加入Uber时,选择了MacBook Pro 13英寸型号,因为它的重量比同品牌其他型号的要轻很多。所以在这里,我愿意在CPU功率和屏幕尺寸之间做一些取舍,因为我在家里和办公室都拥有大型显示器,因此我不太在乎屏幕尺寸。但有意思的是,我目前正在开发一个基于云计算的项目,因此我们正在使用容器进行远程开发。突然之间,所有工作都可以跑在云上,而我笔记本电脑的劣势现在瞬间变成了优势。 2. APEX笔记本电脑支架 我最喜欢的笔记本电脑支架的极简桌面设置 Apex笔记本电脑支架是我早期注册的kickstarter项目之一( https://www. kickstarter.com/? ref=nav )。这个支架花了很长时间才定制完成寄到我手上。但我收到它时,真的感到非常满意

java 反射(Reflection)-干货

本小妞迷上赌 提交于 2020-04-27 04:01:33
看了很多关于java 反射的文章,自己把所看到的总结一下。对自己,对他人或多或少有帮助吧。 Java Reflection是什么? 首先来看看 官方文档 Oracle里面对Reflection的描述: Reflection is commonly used by programs which require the ability to examine or modify the runtime behavior of applications running in the Java virtual machine. This is a relatively advanced feature and should be used only by developers who have a strong grasp of the fundamentals of the language. With that caveat in mind, reflection is a powerful technique and can enable applications to perform operations which would otherwise be impossible. JAVA反射机制是在运行状态中,对于任意一个类,都能够知道这个类的所有属性和方法;对于任意一个对象

Acess a servant server with a reflex-dom client

元气小坏坏 提交于 2020-01-21 10:03:10
问题 I'm using version 0.4 of reflex-dom and I have a tiny reflex-dom client: {-# LANGUAGE OverloadedStrings #-} import Reflex.Dom import qualified Data.Text as T import Data.Monoid main :: IO () main = mainWidget body body :: MonadWidget t m => m () body = el "div" $ do pb <- getPostBuild snd <- button "Send" -- Use one of the following URL's: let defReq = "http://localhost:8080/name/3" -- let defReq = "https://api.nasa.gov/planetary/apod?api_key=DEMO_KEY" let req = XhrRequest "GET" defReq (def {

Acess a servant server with a reflex-dom client

≡放荡痞女 提交于 2020-01-21 10:02:33
问题 I'm using version 0.4 of reflex-dom and I have a tiny reflex-dom client: {-# LANGUAGE OverloadedStrings #-} import Reflex.Dom import qualified Data.Text as T import Data.Monoid main :: IO () main = mainWidget body body :: MonadWidget t m => m () body = el "div" $ do pb <- getPostBuild snd <- button "Send" -- Use one of the following URL's: let defReq = "http://localhost:8080/name/3" -- let defReq = "https://api.nasa.gov/planetary/apod?api_key=DEMO_KEY" let req = XhrRequest "GET" defReq (def {

Where to put the css file when using obelisk

为君一笑 提交于 2020-01-04 06:04:01
问题 I want to make two div's float side by side using Obelisk. For this I used the information from this post, How to place div side by side and for this solution classes have to be declared in css. Following the advice of this tutorial (https://github.com/hansroland/reflex-dom-inbits/blob/master/tutorial.md), more specifically the part about mainWidgetWithHead, I put the commands in a different file. The problem is, however, that I can't find where the css-file should be stored in order to get

How do I build stack configuration that allows me to build project with reflex-frp as dependency?

徘徊边缘 提交于 2019-12-24 09:56:30
问题 As in question. I can't get working stack configuration. I want to build project that uses reflex with ghc, preferably 8.0.2 or higher. How do I do it, cause specifying it as an extra deps doesn't seem to work either.. 回答1: Looks like no published version of reflex supports ghc 8.0.2. There are a lot of changes on the develop branch since the 0.4 release: https://github.com/reflex-frp/reflex/compare/cc62c11a6cde31412582758c236919d4bb766ada...develop So first I tried this: resolver: lts-9.5

Installing reflex-dom likely to break ghcjs

老子叫甜甜 提交于 2019-12-23 21:41:28
问题 I am trying to install reflex and reflex-dom using cabal install I got the following error messages: $ cabal install reflex-dom ... cabal: The following packages are likely to be broken by the reinstalls: lens-4.15.1 ghcjs-0.2.0 free-4.12.4 kan-extensions-5.0.1 adjunctions-4.3 Use --force-reinstalls if you want to install anyway. ghcjs on GitHub is at 0.2.0 on the "master" branch and 0.2.1 on a branch called "dedupe". And I am also scared of breaking lens . Is there any way to install reflex

How can I branch on the value inside a Reflex Dynamic?

耗尽温柔 提交于 2019-12-20 02:56:10
问题 in the simplest case, say I have a Dynamic t Bool , and when the value is true, I want a single empty div to exist, and when the value is false, I don't want there to be any dom element. slightly more generally, if I have a Dynamic t (Either MyA MyB) , and I have functions that know how to render given a Dynamic t MyA or a Dynamic t MyB , how to I call the appropriate function to render? 回答1: If you need to switch the widget you probably need one of: dyn :: MonadWidget t m => Dynamic t (m a)

How can I efficiently branch on the value inside a Reflex.Dynamic?

为君一笑 提交于 2019-12-07 18:14:50
问题 Let's say I have some application state, maintained on some backend system. It looks like this data MyState = State1 MyState1 | State2 MyState2 data MyState1 = MyState1 { ms1_text :: Text, ms1_int :: Int } data MyState2 = MyState2 { ms2_bool :: Bool, ms2_maybe_char :: Maybe Char } I also have a function to get the latest state from the backend system getLatestState :: IO MyState I'm pretty sure I can figure out how to package that up into a Dynamic by repeatedly querying the backend, so that