3 ms·

This thread is, predictably, another demonstration of conflating optimisation with being aware of performance. The presented transformation of code away from “

This thread is, predictably, another demonstration of conflating optimisation with being aware of performance. The presented transformation of code away from “clean” code had nothing to do with optimisation. In fact, it made the code more readable IMO. Then it demonstrated that most of those “clean” code commandments are detrimental to performance. So obviously when people saw the word “performance”, they immediately jumped “omg, you’re optimising, stop immediately!” Another irritating reaction here is the straw man of optimising every last instruction: the course so far has been about demonstrating how much performance there even is on the table with reasonable code, to build up an intuition about what orders of magnitude are even possible. Casey repeated several times that what level of performance is right for your situation will depend on you and your situation. But you should be aware of what’s possible, about the multipliers you get from all those decisions. And of course people bring up profilers: no profiler will tell you whether a function is optimal or not — only what portion of runtime is spent where. And if all your life you’ve been programming in Python, then your intuition about performance often is on the level of “well I guess in C it could be 5-10 times faster; I’ll focus on something else”, which always comes up in response to complaints about Python. Not even close.

loup-vaillant 4y ago
Agreed, but most people here haven't paid for the rest of the course, and Casey sometimes forgot that here he's addressing a wider audience. For instance he fails to explain why he didn't bother addressing the tail of his unrolled loop. He does in the course, but here he's just assuming it's irrelevant, and doesn't address again potential criticism like "he doesn't even bother to write correct code, look at that lazy unrolling!". Thankfully there's a free lecture that explains the broad concept with an example. It's this lecture that convinced me to try out his course, where I hope he'll go into more details: https://www.youtube.com/watch?v=pgoetgxecw8&list=PLEMXAbCVnmY4JbNByvpgEzWsLRKVaF_pk&index=7 https://www.youtube.com/watch?v=pgoetgxecw8&list=PLEMXAbCVnm...
hinkley 4y ago
>what level of performance is right for your situation will depend on you and your situation A lot of my performance and code quality chops came from projects where the team was comfortable with the performance of the system but the business was not. They wanted to stop when it was right for them but not right for the situation. It ended up negatively affecting my opinion of them because ultimately I started to see it as deflecting. It's fine because I don't know what else to do, not because this is the best that can be done.
oleg_antonyan 4y ago
Despite being based on science, software development is full of bs, opinions and lacks measurable metrics. How "clean" this code is? In numbers between 0 and 1 for example. What's the metric there? Does using polymorphism automatically make your code clean? We cannot reliably reason about even single responsibility b/c there's no real measure how to count responsibilities of a function. In such la-la-land some desperately seek any formal measure, and there's one - performance - you can actually put a number on a piece of code. But you cannot do this for code "cleanliness". So some people prefer to ignore unmensurable trait and replace it with measurable
- pnt12 4y ago
  Just because something is hard to measure, doesn't mean it's not important to do - I think there's even a fallacy for that? I think it's also important to separate computer science from software engineering. Algorithms and data structures can be reasoned about mathematically, but what about agile VS waterfall or functional VS oop? Maybe software engineering relates more to philosophy than math. There are theories and some are more sound than others, but there is no objective truth. Most of us agree that it's important for code to be readable, but we still don't have the answer for what's the best readable code. Even first principle such as DRY are challenged, eg by WET. I recall vaguely that there was a situation where there were two schools of thought with different approaches. One was about hacking away things, the other about having correct programs. Maybe Berkeley vs MIT? Such different opinions at the basic level of a discipline are more likely in philosophy than math, I think.
- fartsucker69 4y ago
  Who told you software dev is based on science? It's clearly based on toilet plumbing.

loup-vaillant 4y ago

Agreed, but most people here haven't paid for the rest of the course, and Casey sometimes forgot that here he's addressing a wider audience. For instance he fails to explain why he didn't bother addressing the tail of his unrolled loop. He does in the course, but here he's just assuming it's irrelevant, and doesn't address again potential criticism like "he doesn't even bother to write correct code, look at that lazy unrolling!". Thankfully there's a free lecture that explains the broad concept with an example. It's this lecture that convinced me to try out his course, where I hope he'll go into more details: https://www.youtube.com/watch?v=pgoetgxecw8&list=PLEMXAbCVnmY4JbNByvpgEzWsLRKVaF_pk&index=7 https://www.youtube.com/watch?v=pgoetgxecw8&list=PLEMXAbCVnm...

hinkley 4y ago

>what level of performance is right for your situation will depend on you and your situation A lot of my performance and code quality chops came from projects where the team was comfortable with the performance of the system but the business was not. They wanted to stop when it was right for them but not right for the situation. It ended up negatively affecting my opinion of them because ultimately I started to see it as deflecting. It's fine because I don't know what else to do, not because this is the best that can be done.

oleg_antonyan 4y ago

Despite being based on science, software development is full of bs, opinions and lacks measurable metrics. How "clean" this code is? In numbers between 0 and 1 for example. What's the metric there? Does using polymorphism automatically make your code clean? We cannot reliably reason about even single responsibility b/c there's no real measure how to count responsibilities of a function. In such la-la-land some desperately seek any formal measure, and there's one - performance - you can actually put a number on a piece of code. But you cannot do this for code "cleanliness". So some people prefer to ignore unmensurable trait and replace it with measurable

pnt12 4y ago
Just because something is hard to measure, doesn't mean it's not important to do - I think there's even a fallacy for that? I think it's also important to separate computer science from software engineering. Algorithms and data structures can be reasoned about mathematically, but what about agile VS waterfall or functional VS oop? Maybe software engineering relates more to philosophy than math. There are theories and some are more sound than others, but there is no objective truth. Most of us agree that it's important for code to be readable, but we still don't have the answer for what's the best readable code. Even first principle such as DRY are challenged, eg by WET. I recall vaguely that there was a situation where there were two schools of thought with different approaches. One was about hacking away things, the other about having correct programs. Maybe Berkeley vs MIT? Such different opinions at the basic level of a discipline are more likely in philosophy than math, I think.
fartsucker69 4y ago
Who told you software dev is based on science? It's clearly based on toilet plumbing.