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Writing good code: how to reduce the cognitive load of your code

chrismm.com

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Re: Writing good code: how to reduce the cognitive load of your code

#11

Post by watwut »

kccqzy wrote: post #2

I don't understand the first example. if (null != variable) If this was C, it should be NULL, and it is almost always better to just write `if (variable)` to check for NULL pointers instead. If this was JavaScript, this check includes undefined too. Not sure why it didn't use triple equal. If this was just talking about placing a constant value to be compared before a more complicated expression, I really don't see a…

I haven't wrote in c for years and still don't get what is supposed to be confusing about it.

Maybe he wanted to check for undefined too? Most often you want to treat it the same as null.

Re: Writing good code: how to reduce the cognitive load of your code

#12

Post by flohofwoe »

kccqzy wrote: post #2

I don't understand the first example. if (null != variable) If this was C, it should be NULL, and it is almost always better to just write `if (variable)` to check for NULL pointers instead. If this was JavaScript, this check includes undefined too. Not sure why it didn't use triple equal. If this was just talking about placing a constant value to be compared before a more complicated expression, I really don't see a…

I also don't understand this, nothing wrong about Yoda conditions and I don't understand the 'cognitive load' argument since the condition is just as readable. And: Visual Studio 2015 does not warn in the case of "if (a = 5)", not even at the highest warning level, only the VS2015 static code analyser catches this.

Re: Writing good code: how to reduce the cognitive load of your code

#13

Post by afarrell »

reikonomusha wrote: post #8

Some good previous discussion: Simple Ways of Reducing the Cognitive Load in Code https://news.ycombinator.com/item?id=11992684 My comment there is still relevant here: I've noticed recently that especially in online discussions, the term "cognitive load" is used as a catch-all excuse to rag on code that someone doesn't like. It appears to be a thought-terminating cliché. There's definitely room to talk about objecti…

It is hard to judge the cognitive cost to someone without knowing what that person's pre-existing mental models are.

I don't quite see how cognitive load is a thought-terminating cliche though.

Re: Writing good code: how to reduce the cognitive load of your code

#15

Post by gravity13 »

reikonomusha wrote: post #8

Some good previous discussion: Simple Ways of Reducing the Cognitive Load in Code https://news.ycombinator.com/item?id=11992684 My comment there is still relevant here: I've noticed recently that especially in online discussions, the term "cognitive load" is used as a catch-all excuse to rag on code that someone doesn't like. It appears to be a thought-terminating cliché. There's definitely room to talk about objecti…

I think cognitive load is a perfectly acceptable term here. Taken within the context of Cognitive Load Theory, we assume that any individual can only maintain a few items into their working memory. These items are portions of the code that you need to think about at once in order to achieve a task, and good code partitions off the logic so that in order to understand individual components you only need to reserve a few slots of your working memory.

Of course this is a bit contrived, but I would argue that pretty much everything we've come to understand as "easy to read code" all reduces down to how effectively it organizes itself given the limitations of our working memory. And in that case, it's one of the first things you should be sure to understand on your path to becoming a better programmer.

Re: Writing good code: how to reduce the cognitive load of your code

#16

Post by haswell »

sdegutis wrote: post #9
kccqzy wrote: post #2

I don't understand the first example. if (null != variable) If this was C, it should be NULL, and it is almost always better to just write `if (variable)` to check for NULL pointers instead. If this was JavaScript, this check includes undefined too. Not sure why it didn't use triple equal. If this was just talking about placing a constant value to be compared before a more complicated expression, I really don't see a…

The article says: // This was useful in C to avoid accidentally // typing variable = null. These days it will // confuse most people, with little benefit. The use of "was" and "these days" in the link shows that the author of this piece is in a tiny little bubble of development, and is far from being able to give general advice for programming. C is not past-tense. C, C++, Objective-C, these are all still widely used…

He follows this up with:

> Don’t code “your way”. Just follow the coding standards. This stuff is already figured out. Make your code predictable and easy to read by coding the way people expect.

I'm not a C dev, but is "(null != thing)" still a convention? (Based on your comment it sounds like yes). If yes, it seems to me like he's saying: keep doing that!

Nowhere does he claim that his advice about this convention applies to every language (this would be silly) and not writing C should not preclude someone from giving programming advice.

The "generally applicable" advice that he does give is exactly that: general. Is it possible to write a blog post about code quality/complexity/insert-thing-here that applies to all circumstances? I don't believe it is. It doesn't mean that there is no value to be gained from exploring concepts that may apply.

Re: Writing good code: how to reduce the cognitive load of your code

#17

Post by adamnemecek »

stevecalifornia wrote: post #3

I like code that reads like a Dick & Jane book ("See Dick. See Jane. See Dick run. See Jane run."). However, it appears to be trendy to write insanely difficult to read code. To use the analogy, Shakespearean code. Instead of one line of code doing one thing the developers will write a ton of functionality into one line of code by using fluent and method chaining. As someone reviewing the code I have to keep this men…

This only a problem in dynamically typed languages.

Re: Writing good code: how to reduce the cognitive load of your code

#18

Post by ser0 »

Sometimes I find myself writing in reviews for less experienced developers the comment: this is clever but not clear.

I think as developers we get too enthralled in the problem solving and forget that in the long run we are more like journalists noting business rules at a snap-shot in time, which a future maintainer of our software must act as historian/archaeologist in order to understand.

What's funny is that often our future selves is the maintainer of our software. However, as we lament choices in the past, we continue to write intricate code in the name of elegance/conciseness.

These days I'm pretty pleased when I can say a piece of code utilises only syntax and statements taught in an introductory programming course.

Re: Writing good code: how to reduce the cognitive load of your code

#19

Post by gravity13 »

ser0 wrote: post #18

Sometimes I find myself writing in reviews for less experienced developers the comment: this is clever but not clear. I think as developers we get too enthralled in the problem solving and forget that in the long run we are more like journalists noting business rules at a snap-shot in time, which a future maintainer of our software must act as historian/archaeologist in order to understand. What's funny is that often…

Everything is unclear until you become used to it, though. I mean, used to it, as in, you can read it without stepping yourself through the steps manually. And to a novice programmer, pretty much everything they come up against represents this.

Turning five lines into one line with a reduce function sounds like a normal thing to do for experienced programmers, but to a beginner, they'll think you're a genius for pointing it out to them. So it's not surprising when they try to apply their genius and come up with something clever, too.

Re: Writing good code: how to reduce the cognitive load of your code

#20

Post by to3m »

paxcoder wrote: post #5
kccqzy wrote: post #2

I don't understand the first example. if (null != variable) If this was C, it should be NULL, and it is almost always better to just write `if (variable)` to check for NULL pointers instead. If this was JavaScript, this check includes undefined too. Not sure why it didn't use triple equal. If this was just talking about placing a constant value to be compared before a more complicated expression, I really don't see a…

To paraphrase the comment above that line, they say its purpose is to avoid accidental assignment. That's not an issue with "not equals" though, but that may just be their point. As for whether it's more readable, I'm skeptical: It may save you going through some of the condition, but I believe getting used to it would make you more likely to overlook parts of the condition. Plus, the way it reads is the opposite of…

A NULL literal in c is always zero. The compiler generates code to produce the right address (which may not have all bits reset).
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