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

SEARCH KEYWORD -- Code highlight

  Including Related Objects in Queries

Every time you hit a mobile network, it slows your users down and introduces another point of failure. So when you're designing your application, you need to take advantage of every opportunity to omit needless requests. Parse's philosophy is to help make this easier by providing standard ways to reduce network requests. One example is caching queries, which lets you avoid resending requests you've already sent. Another example, which we've launched in the most recent version of the...

   Software design,Request,Network load,Resource manage,Mobile     2011-12-07 08:51:56

  C Macro Tips and Tricks

Preprocessor vs Compiler To properly understand C macros, you must understand how a C program is compiled. In particular, you must understand the different things that happen in the preprocessor and in the compiler. The preprocessor runs first, as the name implies. It performs some simple textual manipulations, such as: Stripping comments. Resolving #include directives and replacing them with the contents of the included file. Evaluating #if and #ifdef directives. Evaluating #defin...

   C,Macro,Preprocessor,Trick     2012-05-01 06:49:05

  Let 's write some front end codes

I've seen a lot of arguments that there is no much technical value writing web portal, I think that the vast majority of good programmers will try many different things. The low level development and machine learning are not the only technologies which are  full of wisdom and challenges, I wrote web site for a few years, it is difficult to say that this is my initial interest, although I touched on other technologies as well, I still feel building website is challenging. Front end developme...

   Front end development, JavaScript,CSS     2013-01-22 04:00:24

  Understanding lvalues and rvalues in C and C++

The terms lvalue and rvalue are not something one runs into often in C/C++ programming, but when one does, it’s usually not immediately clear what they mean. The most common place to run into these terms are in compiler error & warning messages. For example, compiling the following with gcc: int foo() {return 2;} int main() { foo() = 2; return 0; } You get: test.c: In function 'main': test.c:8:5: error: lvalue required as left operand of assignment True, this code ...

   lvalue,rvalue,C++,locator value,elaboration     2011-12-15 07:51:38

  How big are PHP arrays (and values) really? (Hint: BIG!)

Upfront I want to thank Johannes and Tyrael for their help in finding some of the more hidden memory usage. In this post I want to investigate the memory usage of PHP arrays (and values in general) using the following script as an example, which creates 100000 unique integer array elements and measures the resulting memory usage: <?php $startMemory = memory_get_usage(); $array = range(1, 100000); echo memory_get_usage() - $startMemory, ' bytes'; How much would you expect it to ...

   PHP,Array,Memory occupation,Garbage collection     2011-12-16 10:06:04

  Scala Macros

This is the home page of project Kepler, an ongoing effort towards bringing compile-time metaprogramming to Scala. Our flavor of macros is reminiscent of Lisp macros, adapted to incorporate type safety and rich syntax. Unlike infamous C/C++ preprocessor macros, Scala macros: 1) are written in full-fledged Scala, 2) work with expression trees, not with raw strings, 3) cannot change syntax of Scala. You can learn more about our vision of metaprogramming from our talks. We propose to enrich Scala ...

   Scala,Macro,Efficiency,Maintainebility     2012-02-01 00:12:15

  Forgotten TODOs: ideas for contributing to open-source projects

I often talk to students that want to contribute to open-source projects, but just don't have an idea what to work on. Here's a tip if you're in a similar situation (e.g. you want to apply for GSOC) : 1 git clone repository_url_of_some_open_source_project target_directory 2 grep -RIn TODO target_directory/* So, find the URL of the repository project you want to contribute to, checkout the repository using git/mercurial/svn and then find all the TODOs in the source code using grep. The -RI...

   Open source,constribution,TODO,participation     2012-03-03 22:30:28

  Python internals: adding a new statement to Python

This article is an attempt to better understand how the front-end of Python works. Just reading documentation and source code may be a bit boring, so I’m taking a hands-on approach here: I’m going to add an until statement to Python. All the coding for this article was done against the cutting-edge Py3k branch in the Python Mercurial repository mirror. The until statement Some languages, like Ruby, have an until statement, which is the complement to while (until num == 0 is equi...

   Python,New statement,Research,Addition     2012-03-12 07:32:24

  Python object creation sequence

[The Python version described in this article is 3.x] This article aims to explore the process of creating new objects in Python. As I explained in a previous article, object creation is just a special case of calling a callable. Consider this Python code: class Joe: pass j = Joe() What happens when j = Joe() is executed? Python sees it as a call to the callable Joe, and routes it to the internal function PyObject_Call, with Joe passed as the first argument. PyObject_Call looks at the ty...

   Python,Object creation     2012-04-16 15:03:55

  Supercolliding a PHP array

Did you know that inserting 2^16 = 65536 specially crafted values into a normal PHP array can take 30 seconds? Normally this would take only 0.01 seconds. This is the code to reproduce it: <?php echo '<pre>'; $size = pow(2, 16); // 16 is just an example, could also be 15 or 17 $startTime = microtime(true); $array = array(); for ($key = 0, $maxKey = ($size - 1) * $size; $key <= $maxKey; $key += $size) { $array[$key] = 0; } $endTime = microtime(true); echo 'Inserting...

   PHP,Array,hashtable,Slow,Colliding     2011-12-29 09:02:01

RECENT