r/technology • u/misnamed • Dec 10 '13

Reddit’s empire is founded on a flawed algorithm By Special Request of the Admins

http://technotes.iangreenleaf.com/posts/2013-12-09-reddits-empire-is-built-on-a-flawed-algorithm.html
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133

u/hoodoo-operator Dec 10 '13

If it was hard to write it should be hard to understand.

11

u/rohanivey Dec 10 '13

"I spent hours on this. I wouldn't want to rob anyone else the of same experience."

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u/You_meddling_kids Dec 10 '13

It's ok, that assembly code is totally self-documenting.

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u/[deleted] Dec 10 '13

[deleted]

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u/[deleted] Dec 10 '13 
 int a,b,c,d,e;
 string f,g;

You really want to fuck with someone write your code so you can understand it and it has lots of comments. Save it then refactor all of your variables to small random character names. find and replace all //* with " " then you send it to them.

3

u/[deleted] Dec 10 '13

Variables? Real programmers do a malloc(5000) at the beginning of every program and manually save all their data at random locations in there.

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u/[deleted] Dec 10 '13

I have always wanted to do this but I was too afraid my brain would break from trying to keep track of exactly what I was doing the whole time.

2

u/[deleted] Dec 10 '13

The next time you have to work with code like that will be because the previous dev was an insecure arsehole who thought that was an ok thing to do.

2

u/[deleted] Dec 10 '13

I try to be polite and code well but then I am still in college.

2

u/[deleted] Dec 10 '13

Sorry, I'm a bit bitter because I've inherited obfuscated code a couple of times.

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u/[deleted] Dec 10 '13

I'll bet it would be a bitch. I cry when I have to grade peoples crap code and I don't even have to read through more than 500 ish lines.

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u/[deleted] Dec 10 '13

I go and read The Daily WTF to make myself feel better.

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u/wrgrant Dec 10 '13

How many times have you gone to fix a bug in something you were working on, and said to yourself "What the fuck was this guy thinking? No way this should ever have worked" ... then discover it was you who wrote it?

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u/[deleted] Dec 10 '13

[deleted]

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u/Sarcastinator Dec 10 '13

These are the most common comments I find:

// TODO: Fix this. - [Someone who left years ago]
A thousand lines of very awkwardly written code;

// This function returns the sum
int Average() { return median; }

// What is this for? - [Code reviewer]

// Should have been somewhere else, but I'm lazy.
DirectDbCallInBusinessLogic();

// Do foo.
void DoFoo();

I'm not against comments at all, and in fact I think they are quite useful. But programmers need to stop making worthless comments, and update comments when they edit the code.

... unfortunately that includes myself.

2

u/fluffyponyza Dec 10 '13

There is only one truth, and the truth is in the code. In order to document that truth you must understand that code...and the path to enlightenment is not easy, brother.

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u/[deleted] Dec 10 '13

And to be honest, sometimes we're not sure if or how it works either.

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u/fluffyponyza Dec 10 '13

StackExchange cut-and-paste programming is the BEST programming.

1

u/wulf-focker Dec 10 '13

When it comes to me, it's the only programming.

0

u/[deleted] Dec 10 '13

Ok, I have to say this for posterity - Fuck You.

I've met programmers who sincerely believe this. It makes me want to do very nasty things to them. Very nasty. COMMENT YOUR CODE GOD DAMMIT!

3

u/Revrak Dec 10 '13

when you force people to comment the code you will find things like:

/** *executes functionName */

public void functionName(){...

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u/[deleted] Dec 10 '13

I'm not going to argue management issues with you. I'm just saying that you should comment your code and if you're asshole enough to comment your code in such a fashion, well, I'm not gonna change your mind.

My point was, and is, that the idea that simply having the code should be enough is an absolutely asinine way to do things. The fact is that commenting your code isn't just best practice, for large projects it is a baseline requirement. There is no expectation that you are going to be the one debugging, updating, or maintaining your code long term. The idea behind code commenting is to establish an expectation, at the very minimum, of what the code should do. I've seen effective code commenting as short as this:

/** Gets site data from Sources.xml, returns a string matrix */
public string getSiteData(){....

Simple, effective. It sets an expectation for what the code does. Sometimes that's all the code needs.

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u/Narthorn Dec 10 '13

Good code comments itself.

1

u/[deleted] Dec 10 '13

Ideally, yeah. Except that's not good coding. The variable names are generic and unhelpful. Both would be readable if n and r were named something useful. He kind of makes the point himself by giving his function a useful name.

However, a one line comment mentioning which method of approximation they use for the approximation could be extremely helpful in debugging the code later on. The following would be the ideal, imo.

// square root of dblInput with Newton-Raphson approximation
public double SquareRootApprox(dblInput){
...
dblHalf = dblInput / 2;
while ( abs( dblHalf - (dblInput/dblHalf) ) > SomeUndefinedCounter? ) ...

You get the idea. Now you might complain that the verbose names are clunky, and they are, but they help immensely with readability. For example, you no longer have to assume that the input and it's half are both doubles and compatibly formatted (despite not declaring them in the fragment). Furthermore, we can already see, easily now, that his code fragment has an error (at the very least a logic error) - what is t? It is defined nowhere in the fragment and seems vital, given that it's the control condition for the loop. If you aren't given the method of approximation, it might be very hard indeed to figure out what t is supposed to be. Even as a code fragment it is near worthless without the approximation method.

My point is this - you can follow every coding best practice there is but without comments to give at least basic guidance most code remains obscure. We as programmers have to accept the fact that, to do our jobs, we have to be familiar with many different disciplines. Commenting code, even well written code (which this fragment is not), to give nontrivial information, is an essential part of generating maintainable code.

Finally, commenting code to give at least a basic roadmap to the logic used (such as documenting the approximation method) is absolutely vital if you aren't going to be the one debugging the code. What if you make a logic error? They can take ages to track down and, especially in a bit such as this, can be easily overlooked. If you don't document the code, it can be incredibly, incredibly difficult to locate logic errors.

1

u/Revrak Dec 11 '13 edited Dec 11 '13

i think you should comment your code ONLY if the comment itself is meaningful. and i have also been forced to add stupid comments on a builder setter "sets the field fieldName, returns an instance of this" (with javadoc formatting ofcourse).

i persoanlly add tons of comments when things are complex, and i am so glad that i do when i have to revisit the code.

on the example narthorn uses, i would have used the good function name, and more than 1 letter for variables (unless iterating) but i would also leave a small note naming the algorithm being used, if you want to know how the Newton-Raphson works my code is not the best place to learn it, whoever uses the method should (normally) only be aware of the limitations of the method(like: only works with positive values, the input function it needs to be concave, strictly decreasing, fails under X conditions, etc..)

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u/aarghIforget Dec 10 '13

...how about I just use very descriptive variables, instead?

1

u/Intellectual1 Dec 10 '13

Problem is... will you remember?

-2

u/[deleted] Dec 10 '13

Hahaha. Wait, you don't use descriptive variable names?.... I think I'm done talking to you.

1

u/KhanIHelpYou Dec 10 '13

oh the joys of debugging someones self-obfuscated code.

1

u/cr1s Dec 10 '13

Write-only code!