12 ms·

20 years of application development and I’ve used bit shifting a couple times, none of them were all that essential or much better than the alternatives. It’s a

20 years of application development and I’ve used bit shifting a couple times, none of them were all that essential or much better than the alternatives. It’s a bit condesending and par for the course on HN to be flabbergasted at someone’s lack of knowledge of something but honestly there are career paths where it truely does not matter.

AnIdiotOnTheNet 5y ago
Because it is something that naturally flows from having an understanding of boolean logic and that computers store data in binary digits. Being a "software engineer" who doesn't understand this seems to me like being an architect who doesn't understand trigonometry or something.
- WJW 5y ago
  I mean, if you work as a Staff engineer in a department that only does web app development (say, working at Shopify on their rails codebase) I can easily see that you wouldn't come into any contact with bitwise operators at all. Rather, your time is probably better spent on scaling databases, refactoring codebases and other such higher-level things.
- pcthrowaway 5y ago
  Believe it or not, there are many different kinds of software engineering, many of which don't require you to know anything about binary or bitwise arithmetic. I don't know that I've ever used these as a full stack web developer, but I did learn it in my Computer Science program; the only time I think about the bit position of something is when setting/viewing file permissions, or reading source code for a library which does deal with this (there are legitimate reasons to use bitwise operators in JS for things like hashing, cryptography, secure string generation, etc.) But really, there are people doing software engineering who have never thought about this, and while I agree that any blind spot in knowledge is detrimental (and everyone has some blind spots), it's condescending to suggest that this specific blind spot is noteworthy to the point of lacking foundational knowledge. Your software engineering isn't the only type of software engineering.
  - AnIdiotOnTheNet 5y ago
    I must question the value of a "software engineer" who is working at a layer so abstracted from the reality of implementation that they don't have to understand binary. > the only time I think about the bit position of something is when setting/viewing file permissions, or reading source code for a library which does deal with this (there are legitimate reasons to use bitwise operators in JS for things like hashing, cryptography, secure string generation, etc.) People should understand how the libraries they use work. Not necessarily in detail, but they shouldn't be a magic box they're helpless to understand if it isn't working right. > it's condescending to suggest that this specific blind spot is noteworthy to the point of lacking foundational knowledge. Possibly. I'll admit that though it seems foundationally important to my understanding of computing it may not necessarily be foundational to understanding of computing in a conceptual sense. However, it is so basic, and follows so naturally from boolean logic (which is foundational), that it is quite surprising it never came up for someone in this profession. I mean, if you already know how logic gates work it is trivial to leverage that into understanding bitwise operations.
    - pcthrowaway 5y ago
      > People should understand how the libraries they use work. Not necessarily in detail, but they shouldn't be a magic box they're helpless to understand if it isn't working right. What I'm saying is that 'should' is unfairly prescriptive. There are things I don't understand that would be massively beneficial such as being able to understand drivers and driver code, C (we didn't learn it to any meaningful capacity in my program), and many other skills. Fortunately, I've managed to take what I do know about computing, software, and programming, and find places I can apply that knowledge in a software engineering discipline that utilizes the knowledge I do have most effectively. Would I be able to write a driver if I was being paid to do it? Probably; there would be some learning required, maybe not even that much, but someone would be paying me to learn things outside of my general experience. I'd welcome it as well, but it just hasn't happened. Similarly, there are people whose knowledge encompasses a subset of what I know (but possibly excluding binary and bitwise operations in totality) who are also very effective software engineers. If you can think about browser state, reactivity, CSS specificity, the DOM, and git, you can be a very effective front-end engineer, and you never have to know much about how computers work. There are absolute wizards with 'front-of-front-end' who will be much more effective at animations, effects, device breakpoints, and visually pleasing layouts than I will ever be, who will never think about binary. And it will never be remotely relevant to them.
- afavour 5y ago
  > and that computers store data in binary digits I know that computers store data in binary digits but it has absolutely no impact on how I do my job. I'm vaguely aware of how bitwise operators work but have never had to use them in my work, only in random hacky side projects. > like being an architect who doesn't understand trigonometry or something I'd equate it with a an architect that doesn't know where the brick supplier they are working with sources their bricks from. It's absolute essential to the project, nothing is going to get built without the bricks. But the architect can still plan the use of those bricks and the project can be entirely successful without them needing that knowledge.
  - stickfigure 5y ago
    I'd say it's a bit more like a truck driver who doesn't know how an engine or transmission works. Sure, you can learn the habits just fine, and maybe go your entire career without knowing what goes on under the hood. But sooner or later you're going to get stuck on the side of the road waiting for someone else to come out and fix something trivial.
    - confidantlake 5y ago
      But then you can call AAA and get fixed in under a hour. I would guess the number of truck drivers that know enough about their engine or transmission to fix a trivial issue is <10%. For Uber drivers I would be flabbergasted if it was over 1%. I actually think this is a pretty good analogy. A truck driver does not need to know how to fix their truck to do their job. A web developer does not need to know how to bitshift. For mechanics or low level programmers it is a different story.
  - fungiblecog 5y ago
    But this is like an architect trying to lay bricks without knowing how
    - bandyaboot 5y ago
      It really isn’t.
- wpietri 5y ago
  People can understand that without knowing about bit-shift operators in a given language. I know about them because I had to. My first computer had 4K of RAM. When I hit the limits of Applesoft BASIC, which didn't take long, I had to learn 6502 assembler. Later, I've done things like writing protocol decoders, so I've also learned them in Python. But I think it's perfectly reasonable to have a solid career and never use these. To forget that they ever existed, because one is solving problems where they're just not relevant anymore. Our field is too big to know everything, so I think it's fine that people focus on different aspects of the work.
  - rcurry 5y ago
    Same here, I started on 6502 assembly and you had to know a lot of that stuff just because we didn’t have cool libraries like the STL and so on. You want to sort something, well you’d better write a sort routine.
8ytecoder 5y ago
The common use for bitwise I have seen is to represent multiple boolean states in a single variable. It's not required for most people at all. A more descriptive multi-value hash/struct with each state explicitly listed as a boolean will create a more readable code. Unless there's a strong need for memory management or a binary protocol implementation, I don't see a need for it.
fungiblecog 5y ago
it's the attitude that's the problem. Rolling your own terrible solution without asking someone or just googling first.

AnIdiotOnTheNet 5y ago

Because it is something that naturally flows from having an understanding of boolean logic and that computers store data in binary digits. Being a "software engineer" who doesn't understand this seems to me like being an architect who doesn't understand trigonometry or something.

WJW 5y ago
I mean, if you work as a Staff engineer in a department that only does web app development (say, working at Shopify on their rails codebase) I can easily see that you wouldn't come into any contact with bitwise operators at all. Rather, your time is probably better spent on scaling databases, refactoring codebases and other such higher-level things.
pcthrowaway 5y ago
Believe it or not, there are many different kinds of software engineering, many of which don't require you to know anything about binary or bitwise arithmetic. I don't know that I've ever used these as a full stack web developer, but I did learn it in my Computer Science program; the only time I think about the bit position of something is when setting/viewing file permissions, or reading source code for a library which does deal with this (there are legitimate reasons to use bitwise operators in JS for things like hashing, cryptography, secure string generation, etc.) But really, there are people doing software engineering who have never thought about this, and while I agree that any blind spot in knowledge is detrimental (and everyone has some blind spots), it's condescending to suggest that this specific blind spot is noteworthy to the point of lacking foundational knowledge. Your software engineering isn't the only type of software engineering.
- AnIdiotOnTheNet 5y ago
  I must question the value of a "software engineer" who is working at a layer so abstracted from the reality of implementation that they don't have to understand binary. > the only time I think about the bit position of something is when setting/viewing file permissions, or reading source code for a library which does deal with this (there are legitimate reasons to use bitwise operators in JS for things like hashing, cryptography, secure string generation, etc.) People should understand how the libraries they use work. Not necessarily in detail, but they shouldn't be a magic box they're helpless to understand if it isn't working right. > it's condescending to suggest that this specific blind spot is noteworthy to the point of lacking foundational knowledge. Possibly. I'll admit that though it seems foundationally important to my understanding of computing it may not necessarily be foundational to understanding of computing in a conceptual sense. However, it is so basic, and follows so naturally from boolean logic (which is foundational), that it is quite surprising it never came up for someone in this profession. I mean, if you already know how logic gates work it is trivial to leverage that into understanding bitwise operations.
  - pcthrowaway 5y ago
    > People should understand how the libraries they use work. Not necessarily in detail, but they shouldn't be a magic box they're helpless to understand if it isn't working right. What I'm saying is that 'should' is unfairly prescriptive. There are things I don't understand that would be massively beneficial such as being able to understand drivers and driver code, C (we didn't learn it to any meaningful capacity in my program), and many other skills. Fortunately, I've managed to take what I do know about computing, software, and programming, and find places I can apply that knowledge in a software engineering discipline that utilizes the knowledge I do have most effectively. Would I be able to write a driver if I was being paid to do it? Probably; there would be some learning required, maybe not even that much, but someone would be paying me to learn things outside of my general experience. I'd welcome it as well, but it just hasn't happened. Similarly, there are people whose knowledge encompasses a subset of what I know (but possibly excluding binary and bitwise operations in totality) who are also very effective software engineers. If you can think about browser state, reactivity, CSS specificity, the DOM, and git, you can be a very effective front-end engineer, and you never have to know much about how computers work. There are absolute wizards with 'front-of-front-end' who will be much more effective at animations, effects, device breakpoints, and visually pleasing layouts than I will ever be, who will never think about binary. And it will never be remotely relevant to them.
afavour 5y ago
> and that computers store data in binary digits I know that computers store data in binary digits but it has absolutely no impact on how I do my job. I'm vaguely aware of how bitwise operators work but have never had to use them in my work, only in random hacky side projects. > like being an architect who doesn't understand trigonometry or something I'd equate it with a an architect that doesn't know where the brick supplier they are working with sources their bricks from. It's absolute essential to the project, nothing is going to get built without the bricks. But the architect can still plan the use of those bricks and the project can be entirely successful without them needing that knowledge.
- stickfigure 5y ago
  I'd say it's a bit more like a truck driver who doesn't know how an engine or transmission works. Sure, you can learn the habits just fine, and maybe go your entire career without knowing what goes on under the hood. But sooner or later you're going to get stuck on the side of the road waiting for someone else to come out and fix something trivial.
  - confidantlake 5y ago
    But then you can call AAA and get fixed in under a hour. I would guess the number of truck drivers that know enough about their engine or transmission to fix a trivial issue is <10%. For Uber drivers I would be flabbergasted if it was over 1%. I actually think this is a pretty good analogy. A truck driver does not need to know how to fix their truck to do their job. A web developer does not need to know how to bitshift. For mechanics or low level programmers it is a different story.
- fungiblecog 5y ago
  But this is like an architect trying to lay bricks without knowing how
  - bandyaboot 5y ago
    It really isn’t.
wpietri 5y ago
People can understand that without knowing about bit-shift operators in a given language. I know about them because I had to. My first computer had 4K of RAM. When I hit the limits of Applesoft BASIC, which didn't take long, I had to learn 6502 assembler. Later, I've done things like writing protocol decoders, so I've also learned them in Python. But I think it's perfectly reasonable to have a solid career and never use these. To forget that they ever existed, because one is solving problems where they're just not relevant anymore. Our field is too big to know everything, so I think it's fine that people focus on different aspects of the work.
- rcurry 5y ago
  Same here, I started on 6502 assembly and you had to know a lot of that stuff just because we didn’t have cool libraries like the STL and so on. You want to sort something, well you’d better write a sort routine.

8ytecoder 5y ago

The common use for bitwise I have seen is to represent multiple boolean states in a single variable. It's not required for most people at all. A more descriptive multi-value hash/struct with each state explicitly listed as a boolean will create a more readable code. Unless there's a strong need for memory management or a binary protocol implementation, I don't see a need for it.

fungiblecog 5y ago

it's the attitude that's the problem. Rolling your own terrible solution without asking someone or just googling first.