11/21/12

Tribulations in porting software

Long time no update, time to fix that!

So, last night my friend Morg asked me to port a certain tool (namely, ttm_unpack) to Python from C, since he didn't want to introduce a C-compiler as a dependency for GOGonLinux project. A quick note about GOGonLinux - the project's main task is to make installing games from GOG on Linux as easy as possible. I'm an avid supporter and follower and this is my first major contribution to the project. Join us on #gogonlinux @ freenode and contribute to the codebase!

Back to the topic at hand, since we already had the C-code available I thought "why not?" and said yes, since I thought it would take an hour at maximum with testing.

How wrong can a man be?  Very wrong, I'll tell you that. But in the end, we succeeded, and you can download ttm_unpack_py from my Github-page.

So, what kind of problems did we have while porting the tool?

8/16/12

Curious look into code evaluation

If you have been programming for a while, you already should know about operator precedence. If you for some reason don't, now is a good time to read about it on from Wikipedia or the documentation of your language of choice.

Before proceeding, remember that this may contain some erroneous information, and if you notice any, please inform me so that article can be fixed.

Let's take a rather simple set of expressions:

int i = 5; 
i = ++i + ++i;

This seems rather simple, doesn't it? So did I think, but the results (which we'll see a bit late) left me thinking wtf was actually going on. If we look at the Wikipedia-article, we can see that unary operators such as prefix and suffix increment and decrement come before the addition and substraction, at least in C-family of languages. Now, what do you think the answer will be? Write your guess down somewhere, we'll take a small plunge in to the world of compilers soon.

So, you got your answer? Good. If you did a quick test with a short code of piece, shame on you. Now, let me guess what you got.

If you used Python or Ruby, you got 10.
If you used JS, Java or C#, you got 13.
If you used C, C++ or Perl, you got 14.

Wait, what? How does this even happen?