Small functions considered harmful • Hacker News Board

Re: Small functions considered harmful

#21

Post by shados » Fri, Aug 11, 2017, 12:53 PM UTC

Denzel wrote: post #20

chinhodado wrote: post #10

Earlier quoted context omitted.

> The goal is to develop the wisdom, that makes you a great engineer, not to "follow all of the rules" This is why books like Clean Code can be harmful. It can be extremely dogmatic if blindly followed, which is very common unfortunately.

Clean Code can be harmful? Or the person dogmatically applying the advice? Martin warns against such blind dogmatism. He even goes so far as to explain the thought process behind most of his recommendations so that one may consider whether the rule applies or not. On balance, Clean Code does far more good than it does bad. I have yet to see these dogmatic Clean Coders blindly applying Martin's advice. Not in industry…

> I have yet to see these dogmatic Clean Coders blindly applying Martin's advice.

You're lucky. I've seen it plenty of time. In one extreme case we even had to let go a perfectly (formerly) competent dev after he read that book and went crazy (yeah, seriously).

Re: Small functions considered harmful

#22

Post by sickbeard » Fri, Aug 11, 2017, 12:54 PM UTC

Interestingly the author provides so many reasons why you should use small functions, and less convincing reasons why you should not. Generally, smaller functions are better than the problems that come with their implementations.

Also is it normal to add so many tweets to an article?

Re: Small functions considered harmful

#23

Post by blunte » Fri, Aug 11, 2017, 1:06 PM UTC

The goal is not to make small functions for the sake of making small functions, but it's to compartmentalize some functionality into a nice, easier to reason about thing (function).

Then you compose these easy to reason about things into more complex, but yet still easy to reason about things.

For people like me who struggle to maintain multiple layers of complex abstractions in our minds, being able to see a small function and say, "Ok, I trust this one - it does X." makes it easier to navigate up and down through the abstractions.

Perhaps part of my appreciation comes from living in Clojure and Elixir (after many years of several OOP languages).

Re: Small functions considered harmful

#24

Post by mannykannot » Fri, Aug 11, 2017, 1:11 PM UTC

calafrax wrote: post #17

This discussion is predicated on the concept that function size is calculated by the number of lines which is completely wrong. function size (function complexity actually) is measured primarily by indent levels not length and when there are multiple indent levels with nested branches and loops this is when you are supposed to create functions. length is not really an issue in most cases.

Most of the arguments in the article are agnostic to the size metric - offhand, I cannot think of any claim that is invalidated by changing to your measure. Furthermore, it is the proponents of short functions quoted in the article who are using line count as a metric, so it is not as if the author of this article has created a straw man by choosing a misleading metric.

Re: Small functions considered harmful

#25

Post by whack » Fri, Aug 11, 2017, 1:17 PM UTC

During my earlier years, I would get into all types of dogmatic debates, such as "DRY-considered-harmful" or "small-functions-considered-harmful". With experience, I've realized that such abstract debates are generally pointless. Any principal can lead to bad results when taken to an extreme, or badly implemented. Thus leading to people declaring that-principal-considered-harmful, swinging the pendulum to the opposite extreme, and beginning the cycle all over again.

Now, I find such discussions valuable, but only in the context of concrete examples. Devoid of concrete and realistic examples, the discussion often devolves into attacking strawmen and airy philosophizing. If this article had presented realistic examples of small functions that should have been duplicated and inlined, I think we can then have a much better discussion around it.

That said, I do have to offer a word of warning. It's possible that the author is a good programmer who knows how to incorporate long functions in a way that is still clear and readable. Unfortunately, I've had the misfortune of working with horrendous programmers who write functions that are hundreds of lines long, duplicated all over the place, and are a pain to understand and maintain. Having short-functions and DRYness is indeed prone to abuse, but it still works as a general guideline. Great programmers may be able to ignore these guidelines, but at least it prevents the mediocre ones from shooting themselves (and others) in the foot.

Re: Small functions considered harmful

#26

Post by yen223 » Fri, Aug 11, 2017, 1:20 PM UTC

blunte wrote: post #23

The goal is not to make small functions for the sake of making small functions, but it's to compartmentalize some functionality into a nice, easier to reason about thing (function). Then you compose these easy to reason about things into more complex, but yet still easy to reason about things. For people like me who struggle to maintain multiple layers of complex abstractions in our minds, being able to see a small f…

Small functions are certainly more pleasant to work with in languages that support first-class function composition. Context switching is less of a problem when you can build large functions with only a couple lines of code, just by stitching together multiple small functions.

One big reason why Unix's "one thing well" philosophy works so well for Unix is the ability to chain commands together cheaply, with pipes and redirects.

Re: Small functions considered harmful

#27

Post by enqk » Fri, Aug 11, 2017, 1:22 PM UTC

My theory is that the small functions motif appeared with practitioners of languages where the function is the only tool introducing a new scope / block for variable definitions. Languages like Python or Javascript. What about Smalltalk?

In language where blocks can be introduced at will (stricter Algol descendants like Pascal/C/C++/Java) or are introduced by control structures, then the need for such rule is much less necessary, and only the harm done (friction, readability) by fragmenting and obscuring logic remains.

Re: Small functions considered harmful

#28

Post by al2o3cr » Fri, Aug 11, 2017, 1:25 PM UTC

throwanem wrote: post #15

Obsessive decomposition of the sort Fowler, for example, is cited preferring, very quickly becomes pathological - I suspect that the codebase Fowler describes in that tweet, to the developer as yet unfamiliar with it, reads like one of those old IBM field engineer manuals where a giant circuit diagram is spread across 800 letter-size pages, all bordered with dozens of numbered arrows each referencing the page on whic…

    But if the stuff that needs to change is abstracted, it only has to change in one place.

IMO, the point of "prefer duplication over the wrong abstraction" is that "all the stuff that needs to change" is a partially-to-totally unknown quantity. You can either guess at the time you have the minimum possible amount of knowledge (when the code is initially written) or wait and make that decision later with more evidence.

Even good tests won't save you from premature abstractions with the seams in the wrong places when a change request that cuts across them comes in; they will help as you try to disentangle multiple use cases that go through the same code paths that now need to be different, but it's still a mess. Or worse - you might not disentangle them, and wind up with "generic" code littered with 'if special_case' fragments.

Re: Small functions considered harmful

#29

Post by [deleted] » Fri, Aug 11, 2017, 1:25 PM UTC

coroxout wrote: post #2

I find a lot to agree with here. It's all very conceptually neat and (if you're lucky) easy to read from the top down, where you enter one function and read off a list of other functions which are called in order. But then if you look into any of those other functions they also call more functions and so on, several levels deep. And when you have to debug someone else's code because the data after function 15 of 17 i…

[deleted]

Re: Small functions considered harmful

#30

Post by wiz21c » Fri, Aug 11, 2017, 1:25 PM UTC

coroxout wrote: post #2

I find a lot to agree with here. It's all very conceptually neat and (if you're lucky) easy to read from the top down, where you enter one function and read off a list of other functions which are called in order. But then if you look into any of those other functions they also call more functions and so on, several levels deep. And when you have to debug someone else's code because the data after function 15 of 17 i…

This is a very valuable comment. Indeed pushing the abstraction to small functions actually remove abstraction in the "system of function". So there is a tension.

what I find super interesting in your comment is that you solve this as a team.

So, my point is, this demonstrates (a bit) the fact that coding is also a social activity.

Of course, anything a team produces is a reflection of the team itself.

But here you pinpoint the fact that you adapt your solution to the team as well as to the problem itself (anyone else would have said "I choose this solution because it's the best for the problem")

I like that :-)