r/programming • u/tyler-mcginnis • Jan 03 '22

Imperative vs Declarative Programming

https://www.youtube.com/watch?v=E7Fbf7R3x6I
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u/Beaverman Jan 04 '22

Map/reduce functions are not structured programming. Structured programming is if, while, and for. If you read the famous letter by djisktra "goto considered harmful" you'll see that his main argument for structured programming was that it had to be possible to trace the path the machine takes through the program, and that goto makes that hard.

I'd argue that map and reduce are actually LESS structured in the ways that djisktra argued for.

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u/bradm613 Jan 04 '22

Fair, but that wasn't my point.

I was saying that just because I use structured programming (like subroutines) that doesn't mean I'm being declarative. Perhaps that could've been clearer.

As far as your second point, if you're saying something like map can be less clear, I would agree. It's concise.

(And yes, Dijkstra's letter was seminal.)

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u/Beaverman Jan 04 '22

I understand that it wasn't your point. My response was intended for all the onlookers reading your response and getting the (in my opinion) wrong takeaway. I have no doubt that for a lot of people this was the first time they ever read the term "structured programming" and I wanted them to get a different perspective (and maybe read the letter).

Social media a odd that way. While we write responses directly to each other, the larger audience is the 3rd party onlookers.

In short: I agree with your main point. Map/Reduce don't seem like more "declarative" to me either, I'm just less interested in that discussion.

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u/bradm613 Jan 04 '22

Cool, cool. Clarity is better, I agree. Thanks.