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DRY is an over-rated programming principle?

gordonc.bearblog.dev

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Re: DRY is an over-rated programming principle?

#241

Post by [deleted] »

lowercased wrote: post #207
captainmuon wrote: post #190

Every time I read an article like this, "why is overrated", I think, yeah you are right in theory. But most places I have worked, these best practices were not overused, but underused. If you have the problem that your coworkers create unneccessary abstractions, I envy you, because I have so often had the opposite problem. Maybe this is not the case if you work in a great software development team. But if you work so…

> People not able to factor out functions or structure their code in a readable way. Variables are called v1, v2, v3. Unit testing seen as a waste of time. CI seen as a fun toy. They lack the experience to even notice the difference. Had a colleague work under a 'team lead'. Needed to take a form with variable amount of rows of input data - max 50 - and take data, parse it, and store it. Took 20-30 lines of code. Nex…

[deleted]

Re: DRY is an over-rated programming principle?

#242

Post by nevinera »

captainmuon wrote: post #190

Every time I read an article like this, "why is overrated", I think, yeah you are right in theory. But most places I have worked, these best practices were not overused, but underused. If you have the problem that your coworkers create unneccessary abstractions, I envy you, because I have so often had the opposite problem. Maybe this is not the case if you work in a great software development team. But if you work so…

In rails shops, "dry" is _always_ overused. It was part of the red->green cycle in TDD culture, and got mentioned in every context, and as a result nearly all legacy rails apps are filled with weird abstractions introduced in a commit with a message like "dry it up". The problem is that it's phrased as a rule rather than a smell.

DRY deserves to be listed with other code smells that may indicate a missing abstraction (and there are many), but there is never a reason to blindly extract chunks of code based purely on repetition. That's not a "first step toward good programming", it's a step in the wrong direction.

Re: DRY is an over-rated programming principle?

#243

Post by xigoi »

wruza wrote: post #238
xigoi wrote: post #199

Earlier quoted context omitted.

Why not turn your snippets into actual templates?

What do you mean? I’m currently using vim-snipmate.

I mean, if you have repetitive pieces of code that can be parametrized, why not parametrize them directly in the code instead of using a tool to produce the same code over and over?

Re: DRY is an over-rated programming principle?

#245

Post by fareesh »

DRY requires some judgment

If you have two features that have N parts in common, and you are certain that they will never diverge for feature-specific customization or special cases, then DRY is probably a good idea

If they may diverge at some point, then structuring the code in anticipation of that divergence is a good idea, else you end up with a messy DRY implementation that inevitably has to fork

Re: DRY is an over-rated programming principle?

#246

Post by 12thwonder »

tpoacher wrote: post #221
layer8 wrote: post #188

A better formulation of DRY is SPOT (Single Point Of Truth). Definitions (code, data) that represent the same “truth”, i.e. when one changes all have to change to represent a consistent truth, should be reduced to a single definition. For example, if there is a rule that pizzas need at least one topping, there should only be a single place where that condition is expressed, so that when the rule changes, it isn’t jus…

Occasionally, it's not clear if a single point of truth is entirely appropriate, or even if it is it can lead to tiresome extra levels of abstraction. In this case, I sometimes prefer a slightly different approach; let's call it CRAP - Cross Reference Against Protocol: instead of definitions effectively referring physically to the same point of truth, they are designed instead such that they simply cross reference ag…

can you elaborate on what "protocol" looks like? or can you give us some example?

Re: DRY is an over-rated programming principle?

#247

Post by amcpu »

lowercased wrote: post #207
captainmuon wrote: post #190

Every time I read an article like this, "why is overrated", I think, yeah you are right in theory. But most places I have worked, these best practices were not overused, but underused. If you have the problem that your coworkers create unneccessary abstractions, I envy you, because I have so often had the opposite problem. Maybe this is not the case if you work in a great software development team. But if you work so…

> People not able to factor out functions or structure their code in a readable way. Variables are called v1, v2, v3. Unit testing seen as a waste of time. CI seen as a fun toy. They lack the experience to even notice the difference. Had a colleague work under a 'team lead'. Needed to take a form with variable amount of rows of input data - max 50 - and take data, parse it, and store it. Took 20-30 lines of code. Nex…

Sounds like something out of https://blog.codinghorror.com ! :)

Re: DRY is an over-rated programming principle?

#248

Post by zasdffaa »

awestroke wrote: post #222
lowercased wrote: post #207

Earlier quoted context omitted.

> People not able to factor out functions or structure their code in a readable way. Variables are called v1, v2, v3. Unit testing seen as a waste of time. CI seen as a fun toy. They lack the experience to even notice the difference. Had a colleague work under a 'team lead'. Needed to take a form with variable amount of rows of input data - max 50 - and take data, parse it, and store it. Took 20-30 lines of code. Nex…

Which country was this in?

Elbonia perhaps?

Re: DRY is an over-rated programming principle?

#249

Post by CTmystery »

codesnik wrote: post #206
captainmuon wrote: post #190

Every time I read an article like this, "why is overrated", I think, yeah you are right in theory. But most places I have worked, these best practices were not overused, but underused. If you have the problem that your coworkers create unneccessary abstractions, I envy you, because I have so often had the opposite problem. Maybe this is not the case if you work in a great software development team. But if you work so…

I sometimes use term "mid-level engineer syndrome", for "too many levels of abstraction in the codebase". It is very common in my experience. And untangling it's usually harder then extracting common stuff from "dumb" code. I usually don't DRY things up until three repetitions. And in test code - try to not DRY at all, copypaste is a friend of readable and mantainable specs.

You're almost there, IMO. This internet stranger encourages you to ditch the rule of DRYing based on the number of repetitions at all, and instead think of DRYing based on what deserves to change to together. Sometimes a single repetition in code deserves to be DRY. Sometimes 10 repetitions don't deserve to be DRY.

Re: DRY is an over-rated programming principle?

#250

Post by goodpoint »

kstenerud wrote: post #118

DRY absolutely can get this ugly and messy (I've seen it many times), but I believe that this is largely an experience problem. You have many tiers of DRY knowledge: - Have heard of it and it sounds like a good idea - Let's DRY everywhere! - OK, maybe don't DRY everywhere... - There are multiple ways to implement DRY, and it all depends on circumstance Taking the article example, a better approach would be to DRY the…

That's quite ugly.
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