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362 points mmphosis | 2 comments | | HN request time: 0.42s | source
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leetrout ◴[] No.42165704[source]
> It's better to have some wonky parameterization than it is to have multiple implementations of nearly the same thing. Improving the parameters will be easier than to consolidate four different implementations if this situation comes up again.

Hard disagree. If you cant decompose to avoid "wonky parameters" then keep them separate. Big smell is boolean flags (avoid altogether when you can) and more than one enum parameter.

IME "heavy" function signatures are always making things harder to maintain.

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thfuran ◴[] No.42165868[source]
I think it's especially bad advice with the "copy paste once is okay". You absolutely do not want multiple (even just two) copies of what's meant to be exactly the same functionality, since now they can accidentally evolve separately. But coupling together things that only happen to be mostly similar even at the expense of complicating their implementation and interface just makes things harder to reason about and work with.
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atoav ◴[] No.42166007[source]
My experience is totally different. Sure the popular beginners advice is to never repeat yourself, but in many cases that can actually be a viable operation, especially when you are okay with functions drifting apart or the cases they handle are allowed to differ.

And that happens.

The beginners problem lies in the reasons why that happens — e.g. very often the reason is that someone didn't really think about their argument and return data types, how functions access needed context data, how to return when functions can error in multiple ways etc, so if you find yourself reimplementing the same thing twice because of that — sure thing, you shouldn't — what you should do is go back and think better about how data is supposed to flow.

But if you have a data flow that you are very confident with and you need to do two things that just differ slightly just copy and paste it into two distinct functions, as this is what you want to have in some cases.

Dogmatism gets you only so far in programming.

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wruza ◴[] No.42167672[source]
I think that it’s our tooling sucks, not us. Cause we only have functions and duplicated code, but there’s no named-common-block idea, which one could insert, edit and

1) see how it differs from the original immediately next time

2) other devs would see that it’s not just code, but a part of a common block, and follow ideas from it

3) changes to the original block would be merge-compatible downwards (and actually pending)

4) can eject code from this hierarchy in case it completely diverges and cannot be maintained as a part of it anymore

Instead we generate this thread over and over again but no one can define “good {structure,design,circumstances}” etc. It’s all at the “feeling” level and doing so or so in the clueless beginning makes it hard to change later.

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1. rileymat2 ◴[] No.42171430[source]
Without the encapsulation of a function, won’t the code around the common block depend on the details of the block in ways that cause coupling that make the common block hard to change without detailed analysis of all usages.

I like what you are saying, i think, but am stuck on this internal coupling.

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2. wruza ◴[] No.42191382[source]
It will share nuance with non-hygienic macros, yes. The difference here is that (1) unlike macros which hide what’s going on, the code is always expanded and can be patched locally with the visual indication of an edit, and (2) the changes to the origin block aren’t automatically propagated, you simply see +-patch clutter everywhere, which is actionable but not mandatory.

If you want to patch the origin without cluttering other locations, just move it away from there and put another copy into where it was, and edit.

The key idea is to still have the same copied blocks of code. Code will be there physically repeated at each location. You can erase “block <name> {“ parts from code and nothing will change.

But instead of being lost in the trees these blocks get tagged, so you can track their state and analyze and make decisions in a convenient systemic way. It’s an analysis tool, not a footgun. No change propagates automatically, so coupling problem is not a bigger problem that you would have already with duplicated code approach.

You can even gradually block-ize existing code. See a common snippet again? Wrap it into “block <myname> {…}” and start devtime-tracking it together with similar snippets. Don’t change anything, just take it into real account.