Today's Question:  What does your personal desk look like?        GIVE A SHOUT

SEARCH KEYWORD -- Obj

  How to write your own DSL in Ruby

DSL(Domain Specific Language) is a language defined to fulfill some domain specific requirements to ease people's work. It can be used to define attributes and actions of a domain easily and cleanly. And it is often created based on some common observations or micro patterns of some domain. In Ruby world, there are quite a few places people can find DSL. For example, Ruby itself, Chef recipes. To create a class in Ruby, the traditional OOP way would look like. class User @name = nil @email =...

   RUBY,DSL,TUTORIAL     2017-03-04 09:40:34

  Learn from Haskell - Functional, Reusable JavaScript

Learn You a Haskell: For Great Good? For the last couple months I have been learning Haskell. Because there are so many unfamiliar concepts, it feels like learning to program all over again. At i.TV, we write a lot of JavaScript (node.js and front end). While many functional/haskell paradigms don’t translate, there are a few techniques that JS can benefit from. There are Haskell library functions for everything. At first I thought this was just because it was mature, but then I notice...

   JavaScript,Haskell,Functional,Reusability,Feature     2012-02-21 05:30:51

  this in JavaScript in detail

this in JavaScript is always confusing, it is one of the most frequently seen traps in JavaScript. this is not a good design in JavaScript(You can refer some other design flaws of JavaScript here), since it's lazy binding feature, it can be a global object, the current object or.... Some people even avoid using this in JavaScript. Actually if you master how this works, then you will know how to stay away from these traps. Let's take a look at what this points to in below situations. 1. In global...

   JavaScript,this,bind     2013-05-09 18:35:12

  Mutli-inheritance bug between python 2.7 and 3.7

When we have run a py3.7 code under py2.x or a py2.x code under 3.x ,if a class do mutli-inheritance from 2 parent and the 2 parents also got inheritance from same parent, the different way to handle inheritance chain between python 2 and 3 will cause some running time bug: Assume we got this sample program inheritTest.py : # Purpose: Test mutli-inheritance different between python2 and 3 # Author: Yuancheng Liu # Created: 2019/05/16 class A: def getVal(self): print("cal...

   PYTHON,PYTHON 3,INHERITANCE     2019-05-16 08:33:52

  An Object is not a Hash

Following my article A String is not an Error, I want to bring attention to an issue that similarly applies to JavaScript in general, but has special relevance in the Node.JS environment. The problem boils down to the usage of {} as a data-structure where the keys are supplied by untrusted user input, and the mechanisms that are normally used to assert whether a key exists. Consider the example of a simple blog created with Express. We decide to store blog posts in memory in a {}, indexed ...

   Object,Hash,Node.js,JavaScript     2012-01-19 10:16:10

  Can a === 1 && a === 2 && a === 3 be true in JavaScript?

Lots of you may be aware that there is famous interview question which asks whether a == 1 && a == 2 && a == 3 can be true in JavaScript. And the answer to this question is YES. The reason is that == will do a non-strict comparison which will evaluate a to a number and this provides the possibility of dynamically return the value when every time a is accessed. Have you ever wondered whether a === 1 && a === 2 && a === 3 can be true? At first glance, it seems this ...

   JAVASCRIPT,===,STRICT COMPARISON     2018-04-06 12:17:29

  JavaScript's Two Zeros

JavaScript has two zeros: -0 and +0. This post explains why that is and where it matters in practice. The signed zero Numbers always need to be encoded to be stored digitally. Why do some encodings have two zeros? As an example, let’s look at encoding integers as 4-digit binary numbers, via the sign-and-magnitude method. There, one uses one bit for the sign (0 if positive, 1 if negative) and the remaining bits for the magnitude (absolute value). Therefore, -2 and +2 are encoded as f...

   JavaScript,zeros     2012-03-24 05:21:49

  Prototypes in JavaScript

Following on from his previous article, David Chisnall explores JavaScript as an example of prototype-based object orientation. In this article, he shows how it's possible to implement more complex object models on top of this simple abstraction.My previous article, Prototypes and Object Orientation, considered the differences between class-based and prototype-based object orientation. In this article, we'll look in a bit more detail at the workings of the JavaScript object model, since it'...

   JavaScript,Prototype,Object oriented,Obj     2011-09-02 11:44:12

  A simple tutorial on writing Java native program

Java provides Java Native Interface(JNI) to enable developers to write programs which can utilize the underlying native libraries of the operating system. The benefits of writing native code are that they normally provide better performance compared to Java codes. Sometimes if you want to utilize some system specific functions you may also want to use JNI. One main drawback of writing native code is that your application may not be platform independent anymore. This is not what Java is desi...

   Java native interface, JNI, Native code, Sample     2015-08-15 08:28:15

  High performance web apps with C++

It is Christmas over here, and it is time of giving. So I decided to give something back to the community. I guess this is as old as web programming itself. Trying to create C++ web framework. If you search on the web, you can find dozen of guys that had exactly the same idea. I am not different. For one of the previous projects(discontinued now) I created simple web framework in C++. If you like to hack in C++, here it is. Code is provided as-is, as part of larger application. You can ex...

   C++,Web apps,Web framework     2012-01-08 10:06:48

RECENT