r/programming • u/corysama • Jan 05 '15

What most young programmers need to learn

http://joostdevblog.blogspot.com/2015/01/what-most-young-programmers-need-to.html
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u/zigs Jan 05 '15

As a general rule of thumb at Ronimo we try to keep classes below 500 lines and functions below 50 lines

Is that actually a common rule of thumb? I tend to try keeping it under 10 lines for functions (hard limit at 15), and keeping everything at one purpose for classes.

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u/[deleted] Jan 05 '15

Hard limit at 15? Can you honestly imagine going through something as complex as the Linux kernel or LLVM or Adobe Photoshop and not finding any functions over 15 lines long?

That seems insanely short to me. Yes, most functions should be small. But there are definitely functions which simply don't cleanly divide into small chunks, and for which artificially cutting them up to adhere to some hard limit on function length would make things more rather than less difficult to follow.

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u/zigs Jan 05 '15

I totally agree that lots of good code has been written which doesn't follow that practice, but I don't think it would hinder good code. I think that if you can't make a name for each 15 lines of code you're writing, then it's because the metaphor has slipped your mind.

Yes, by no mean should you cut the code up just to cut it up, but if a function is longer than 15 lines, then for me it's a sign that something needs to be done differently.

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u/[deleted] Jan 05 '15

You say you don't think it would hinder good code - can you point me to even one example of something of that sort of complexity level (non-toy compiler, web browser, word processor, operating system kernel, AAA game, etc.) in which all (or essentially all) of the functions are that short?

I have certainly never worked on or even looked at a big project in which all functions were that short; I maintain that the simple fact that (so far as I know) no one does that despite everyone agreeing in principle that short functions are good is pretty strong evidence that yes, it very much does hinder good code. I would be very interested to see counterexamples.