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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

#81

Post by optimuspaul »

dualogy wrote: post #52
MrLeap wrote: post #30

Earlier quoted context omitted.

To get you started, I'd like to compare my problems regarding `if = ` with yours. This assumes you aren't the kind of lunatic to actually assign a constant inside of an if's condition. 1. I can't articulate exactly why, but that should totally be flipped. The constant should be on the right side! `if(3.17 == possiblyPi)` would make me seriously question the author's motives. 2. It's personal preference, but in almost…

> 3.17 == possiblyPi Seems bad style to me, but also contrived. Whereas > PI == validate(parseFloat(fetchUserInput({ timeout: minutes(1), defaultOnCancel: 0.0 }))) as pseudo-code example seems rather more insta-grokkable to me than flipped. Get my drift? And it's lit==varExpr

I don't agree...

but I also generally use languages that don't have equality and assignment operators that are so similar that people are prone to mixing up the two.

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

#83

Post by MaulingMonkey »

haswell wrote: post #16
sdegutis wrote: post #9

Earlier quoted context omitted.

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…

> I'm not a C dev, but is "(null != thing)" still a convention?

Configuring the warning your compiler gives for 'if (x=y)' to generate an error instead is a vastly better convention that completely supersedes Yoda style, IMO. 'if ((x=y))' remains available for those who really want to assign in conditionals.

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

#84

Post by to3m »

flohofwoe wrote: post #12
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.

With Visual Studio 2015 update 3, and /W4, I get "warning C4706: assignment within conditional expression" for stuff like "if(a=5)", both in C and C++.

(C4706: https://msdn.microsoft.com/en-us/library/7hw7c1he.aspx)

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

#85

Post by dualogy »

optimuspaul wrote: post #81
dualogy wrote: post #52

Earlier quoted context omitted.

> 3.17 == possiblyPi Seems bad style to me, but also contrived. Whereas > PI == validate(parseFloat(fetchUserInput({ timeout: minutes(1), defaultOnCancel: 0.0 }))) as pseudo-code example seems rather more insta-grokkable to me than flipped. Get my drift? And it's lit==varExpr

I don't agree... but I also generally use languages that don't have equality and assignment operators that are so similar that people are prone to mixing up the two.

Who has ever mixed up == and =? Might glasses be in order? ;)

No danger in languages allowing for FP-style immutables (whether via `readonly` or `const`) luckily

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

#86

Post by MaulingMonkey »

flohofwoe wrote: post #12
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.

A non-static-analysis option:

  #pragma warning(error: 4706)
Interestingly I cannot seem to enable this warning at all via the command line. EDIT: From bellow, possibly a VS2015 U1 bug fixed on-or-before VS2015 U3.

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

#87

Post by MaulingMonkey »

to3m wrote: post #84
flohofwoe wrote: post #12

Earlier quoted context omitted.

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.

With Visual Studio 2015 update 3, and /W4, I get "warning C4706: assignment within conditional expression" for stuff like "if(a=5)", both in C and C++. (C4706: https://msdn.microsoft.com/en-us/library/7hw7c1he.aspx )

I cannot generate the warning via command line flags only (including getting very insistent with /wall /w14706 /we4706 ) on VS2015 update 1, presumably a bug.

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

#88

Post by lacampbell »

awinter-py wrote: post #53
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…

Hmm -- you're talking about programming in the small, as in line-by-line style. Cognitive load also affects devs at the scale of a whole project, i.e. understanding how the program fits together across different modules, across state changes and across time. What's the dick & jane solution for project-scale organization?

Bingo. People like to hold forth on the small scale - but what about communication between components?

I watched "The Art of Destroying Software" [1] the other day and I've been thinking about the concepts a lot. Thought provoking talk - apart from the surveys he keeps conducting.

Making a nice method isn't that great. But a nice "component" or "module" or "service" - that's the key. Try and break your program up into little programs. But not too little... maybe that's the way?

[1] https://vimeo.com/108441214

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

#89

Post by psyc »

onion2k wrote: post #39
MrLeap wrote: post #30

Earlier quoted context omitted.

To get you started, I'd like to compare my problems regarding `if = ` with yours. This assumes you aren't the kind of lunatic to actually assign a constant inside of an if's condition. 1. I can't articulate exactly why, but that should totally be flipped. The constant should be on the right side! `if(3.17 == possiblyPi)` would make me seriously question the author's motives. 2. It's personal preference, but in almost…

I can't articulate exactly why, but that should totally be flipped. Should it? If you accidentally use an assignment operator (eg = ) instead of a comparison (eg === )[1] with the constant on the left your code will throw an exception, which is what you want. If you put the variable on the left and accidentally use an assignment then you'll overwrite the variable with the constant value and return true, consequently…

This 'reason' is as old as C, and it's always seemed to me like tying bells to your shoelaces because it would be bad if you forgot to tie them and tripped. I.e. the 'solution' is orthogonal to the problem. If you can train yourself to put the constant first, you can train yourself to use the right operator.

And you can test your code.

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

#90

Post by [deleted] »

TimJYoung wrote: post #21
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…

I can't up-vote this enough. As someone that started doing development in the late 80's, I find this style of coding to be infuriating. It completely destroys the ability to map lines of code directly to function calls without resorting to manual coding rules that require that each .function() be on a separate line, and makes debugging way harder than it needs to be. And, for what purpose ? To avoid a local, temporar…

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