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John Carmack discusses the art and science of software engineering

271 points by gb 14y ago

deleted 14y ago
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- pasbesoin 14y ago
  For me, it stated that Javascript for Safari Mobile was turned off. Same result, though; remove two overlays -- one for the JS message, and another that simply masks the underlying content, and that underlying content is perfectly visible. I guess it's kind of pointless to comment, but I continue to resent the applicationization of basic content (data). In good part because it remains a security concern.
- smspence 14y ago
  ...who cares? Do you have any thoughts or comments about the actual topic of the post? This is an article written by one of the most innovative, influential, and successful software developers in the world, giving a lot of interesting insights and thoughts on his craft. ...and you're concerned about the HTML/JS of some shitty wordpress template? We get it, you probably work in web development. Yes, poorly-coded websites exist. That's not what the content of the post is actually about. This is part of the decline in quality of Hacker News. When an article is posted, let's talk about the article, instead of pedantic off-topic garbage.
  - deleted 14y ago
    [deleted]
cobrausn 14y ago
Running your code through static analysis can be eye-opening. And just like when you opened your eyes for the first time... you'll probably cry.
- figglesonrails 14y ago
  If I had a dollar for every time I saw this... if(obj == null && obj.isValid()) I'd have approximately 960 dollars per project.
  - jabbernotty 14y ago
    > if(obj == null && obj.isValid()) Why would you encounter this (often)? It seems to me that this code would never evaluate to true.
    - mathgladiator 14y ago
      I hope he means > if (obj != null && obj.isValid()) { } Which is semantically correct due to the fail-fast evaluate of AND, it does require a double check since it's strange from a logic point of view. This is one the reasons that brace languages are hard to optimize since you can't commute things that ought to commute.
      - astrange 14y ago
        That statement can't be commuted because it expresses a concept that can't be commuted. If the two checks were independent (pure functions), it's not difficult for a compiler to determine that given enough program visibility.
    - arnsholt 14y ago
      It's a braino, I think. Instead of the right thing, which would be what mathgladiator posted below, this is a guaranteed null pointer exception when obj actually is null.
    - figglesonrails 14y ago
      This is Java code. If you test for a null reference AND THEN dereference it, you get a NullPointerException. The check was supposed to be "!= null". This check is obviously erroneous, and found via SCA. I was saying "if I had a dollar for every time I found this [via SCA] I'd have a lot of money."
VMG 14y ago
If he wrote a book about programming, I'd buy it in a heartbeat. Too bad that even he probably is still figuring everything out.
- bsphil 14y ago
  The more you know, the more you realize you don't know. That would be a great book though.
  - K2h 14y ago
    I came to that same conclusion a few years ago. Sometime in college I was pretty happy, felt I was making good progression on real knowledge in a field. Now, a few years later - I'm not sure what I know is real and true, which are high order approximations, and which are flat out wrong, but still right enough to not cause too many problems. an example: in grade school you learn how to mix colors, primary colors with paints, etc. then a little later, in middle school you learn no.. for light based, its not the same type of addition. then a little later you learn there are like an infinite possible primary colors - then a little later you learn color is actually a frequency or combination of frequencies, and you start asking yourself if your friend detects these colors the same way you do. does red to you really look blue to your friend. it just gets weird.
    - lttlrck 14y ago
      love this example!
    - K2h 14y ago
      look what shows on HN today: negative frequency for light. things really do get weird. https://hackerne.ws/item?id=4429234 https://hackerne.ws/item?id=4429234
  - whalesalad 14y ago
    Yep. Also, the smarter you are the more you tend to doubt yourself. Whereas less intelligent people tend to have more confidence in what they're doing. Bites me in the ass all the time.
figglesonrails 14y ago
Actually, I think one of his strongest points is about making mistakes -- everyone does them and everyone makes the most amateur of them. If you haven't tried running SCA on your code, try it sometime. I've got a ridiculous ego, but when you get hundreds of warnings on your code, you realize just how imperfect you can be and how impossible it is to be cognizant of all things at all times. This is why teams are almost always better, and I'd prefer to review and be reviewed by someone else -- I'm my own biggest blind spot.
musashibaka 14y ago
I would suggest watching his entire talk on youtube: http://www.youtube.com/watch?v=wt-iVFxgFWk http://www.youtube.com/watch?v=wt-iVFxgFWk
- wwwtyro 14y ago
  I was glued to the screen for the entirety of that talk. That guy is completely engrossing to listen to.
- Keyframe 14y ago
  Three and a half hours?? I better grab some popcorns then.
- tkahn6 14y ago
  Definitely worth watching. It's more like a tech talk than a keynote. Extremely good insight in there.
dllthomas 14y ago
The talk itself is well worth the 3 hours.
prawks 14y ago
I look forward to the QuakeCon keynote every year. Anyone who engineers software should really listen to Carmack. Also, this article's kind of silly... there's almost no discussion? Just watch the video. EDIT: I guess it's not so much an article as a sharing of info. Still. Watch the video.
pnathan 14y ago
One of the things I've been persuaded of is that software writing is fundamentally a non-scientific activity. Outside of the time and space constraints for a given subsystem, the craft of software is almost entirely subjective and limited only by mental capacities and flaws.
jcdavison 14y ago
i just finished the devbootcamp program so as a person who was thrown into oo programming with no real cs underpinnings, it is interesting to hear him talk about the social component . it is also pretty interesting to here him talk about making mistakes and the need to just get things done versus optimization.
nightski 14y ago
He is definitely right about the social aspect of software engineering. But I think he sells a lot of the tools short. For example, he brings up things like Monads, Lambda Calculus, and whatnot - but then immediately dismisses them as not affecting what one truly does. But I think this really misses the point. In our industry it is really easy to disguise oneself as a professional (or even just someone who knows what they are doing), without really knowing much of anything. Meaning, our focus as an industry has been on making the simple things as simple as possible (i.e. scripting/dynamic languages, code generation, frameworks). But what I see happening in the Haskell space for example (and even further in languages such as Agda) are attempts to distill things down to their elements. To find the true semantics behind a problem. This not only helps by producing cleaner and more readable code, but it also helps with communication. I really do believe software is a scientific (and mathematical) exercise. The problem is most of industry does not treat it as such, and hence we end up in the mess we are in.
- rprospero 14y ago
  While I love what Haskell has done for me as a programmer, I don't think that it's finding the true semantics behind our problems. I rather think that it's finding a different basis. To take an analogy, monads and lambda calculus are like Fourier series. For many classes of problems, they produce a cleaner, simpler understanding of the solution. I'd hate to try and solve a boundary value problem with just Taylor series. However, while expressing linear functions with Fourier series is possible, it's less clear than the Taylor series and you're more likely to mess it up. In the same way, monads, arrows, and recursion are great ways of describing many classes of programs. Additionally, they help with communication when your problem is a monad or an arrow. However, certain classes of problems are better described under other paradigms than being forced into the functional one. This comes back to Carmack's point. It's important to know Haskell, since it's distilled computation down to a set of elements which are useful for describing a large class of problems. Being able to communicate these solutions is important. However, other paradigms are less error prone and do communicate solutions more clearly on other classes of problems.
  - nightski 14y ago
adjwilli 14y ago
I program mostly in Objective-C nowadays, but I started professionally with PHP. When I first started Objective-C, I found it really constricting in comparison. In PHP you can do things a thousand ways, most of the terrible. In Objective-C, specifically with Cocoa, things are a lot more rigid and prescribed. I found this frustrating, but love it now. It's made my PHP better too when I do occasionally go back. It forced me to think more about architecture. I also understand why my CS dept taught us Scheme first, not Java. To link that back to the post, this is the type of constriction he's talking about to make better programmers. Cocoa and Objective-C restricted me to only writing at least halfway decent code. With PHP, because of it's flexibility, you're free to get things done quickly, but in a terrible way. Sure with PHP you can do things right too, but it takes a lot more self-discipline and also a priori knowledge. Sorry to post yet another rag on PHP.
- Androsynth 14y ago
  Its not ragging when its constructive with a thoughtful argument.
HeyLaughingBoy 14y ago
With the NASA style development process, they can deliver very very low bug rates, but it’s at a very very low productivity rate I wonder how many non-developers understand this. I, along with the rest of my team, am trained in PSP (http://www.sei.cmu.edu/library/abstracts/reports/00tr022.cfm http://www.sei.cmu.edu/library/abstracts/reports/00tr022.cfm) and TSP (http://www.sei.cmu.edu/tsp/ http://www.sei.cmu.edu/tsp/) and we use it in our day-to-day development. It definitely helps us keep our defect rate below one bug/kLOC but it's an expensive process that results in very low LOC/day productivity. If very low shipped bug counts are very important to your organization, great. But most businesses these days seem to care more about having a usable product than they do a perfect (or close to it) product. Especially if it's on the Web where you can do multiple releases per day. As an industry, we really need to bear in mind that different business domains need radically different approaches to software engineering.
- pnathan 14y ago
  Can you follow up with some information about the (P|T)SP experience? I looked into it about a year ago and thought it was a ridiculous amount of overhead, and the blurbs about the initial data Humphrey used to create it was not persuasive. The "take our class" ads were not encouraging either. So if its working for you in actual development, I'd LOVE to hear more about what it does/doesn't do for you.
  - HeyLaughingBoy 14y ago
    First, it helps to understand that even before moving to PSP/TSP, we were already in a process-heavy regulated Medical Device development environment, so it wasn't a big change. My understanding is that many teams starting with TSP didn't have much of a process to begin with. The good: PSP encourages a high level of developer responsibility for quality. So you use a checklist to review your code before running the unit tests. You record every defect you find and if applicable, use that information to make a better checklist. Every team has a TSP-trained Coach to guide the process, answer questions, and keep the team on track. The metrics generated from the process are analyzed weekly to see if the team is on target, if quality is where the predictions say it should be and if there are any roadblocks. The bad: it can be a major change to how you are used to working. The data collection, while as automated as possible, is annoying. The constant emphasis on tracking time on various stages of fixing a bug/adding a feature adds a noticeable amount of friction to your workflow. While it's not Waterfall, TSP is definitely not Agile. Its entire focus is on predictability of output. It's an attempt to take what works well for Manufacturing and apply some of that to software dev. In short, TSP/PSP is a good idea at heart for those types of development where initial product quality is critical or where you may never have a chance to fix a defect. This is not the case for most instances of modern software projects.
zxcvbn 14y ago
Richard Feynman wrote[1]: "We could, of course, use any notation we want; do not laugh at notations; invent them, they are powerful. In fact, mathematics is, to a large extent, invention of better notations. The whole idea of a four-vector, in fact, is an improvement in notation so that the transformations can be remembered easily." What he said about mathematics, I think it applies even more to programming. [1] The Feynman Lecture on Physics, Volume 1, Chapter 17
- 6ren 14y ago
  At PARC we had a slogan: "Point of view is worth 80 IQ points." It was based on a few things from the past like how smart you had to be in Roman times to multiply two numbers together; only geniuses did it. We haven't gotten any smarter, we've just changed our representation system. We think better generally by inventing better representations; that's something that we as computer scientists recognize as one of the main things that we try to do. Alan Kay http://billkerr2.blogspot.com.au/2006/12/point-of-view-is-worth-80-iq-points.html http://billkerr2.blogspot.com.au/2006/12/point-of-view-is-wo...
  - taybin 14y ago
    According to this, multiplication wasn't so bad: http://turner.faculty.swau.edu/mathematics/materialslibrary/roman/ http://turner.faculty.swau.edu/mathematics/materialslibrary/...
    - e12e 14y ago
      Without a table? Just from memory? I think I'd prefer decimal.
    - btilly 14y ago
      Actually real Romans did multiplication on an abacus. Reading from Roman numerals to/from an abacus is an incredibly natural operation. In Europe the disappearance of abacuses was directly tied to the rise of Arabic notation.
jberryman 14y ago
I don't want to be an ass, but this seems like a lot of vague contradictory rambling. Maybe I missed some big ideas in the parts I skimmed?
- rapala 14y ago
  I was also a bit confused. He said that stuff like monads are nice, but not that useful in the end. On the other hand, he seemed concerned about how to enforce best practices, to which I count monads in.
Arjuna 14y ago
Interesting comments on Mac and Linux platforms [1]: "Other interesting sort of PC-ish platforms, we have... the Mac still remains a viable platform for us. The Mac has never required any charity from id, all of those ports have carried their own weight there; they've been viable business platforms. I actually think that the Mac is going to become a little bit more important for us. Interestingly, we have a ton of people that use, like Macbooks at the office, but we don't have any really rabid, OS X fanboys at the company that drive us to go ahead and get the native ports out early. But, one of my pushes on the greater use of static analysis and verification technologies, is I pretty strongly suspect that the Clang LLVM sort of ecosystem that's living on OS X is going to be, I hope, fertile ground for a whole lot of analysis tools and we'll wind up benefiting by moving more of our platform continuously onto OS X just for that ability to take advantage of additional tools there. Linux is an issue that's taken a lot more currency with Valve announcing Steam for Linux, and that does change, factor, you know, changes things a bit, but we've made two forays into the Linux commercial market, most recently with Quake Live client, and, you know, that platform just hasn't carried its weight compared to the Mac on there. It's great that people are enthusiastic about it, but there's just not nearly as many people that are interested in paying for a game on the platform, and that just seems to be the reality. Valve will probably pull a bunch more people there. I know absolutely nothing about any Valve plans for console, Steam-box stuff on there; I can speculate without violating anything. One thing that also speaks to the favor of Linux and potential open source things is that the integrated graphics cards are getting better and better, and they really are good enough now. Intel's latest integrated graphics cards are good. The drivers still have issues. They're still certainly not going to blow away somebody's top of the line SLI system, but they are completely competent parts that are delivering pretty good performance. And one of the wonderful things is that Intel has been completely supportive of open source driver efforts, that they have chipset docs out there, and they work openly with community to develop that, and that's pretty wonderful. I mean, anybody that's a graphics guy, if you program to a graphics API, use D3D or OpenGL, you owe it to yourself at some point to go download the Intel chipset docs. There's hundreds of pages of them, but you really should read through and see what happens at the hardware level. It's not the same architecture that Invida and AMD have on there, but there's a lot of commonalities there. You'll grow as a graphics developer to know what happens down at the bit level. Another one of those things, if I had more time, if I could go ahead and clone myself a few times, I would love to be involved in working on optimizing the Intel open source drivers there. So, it's enticing, the thought there that you might have a well-supported, completely open platform that you could deliver content through the Steam ecosystem there. It's a tough sell on there, but Valve gets huge kudos for having the vision for what they did with Steam, sticking through all of it. It's funny talking about Doom 3, where we can remember back in the days when they're like, 'Well, should you ship Doom 3 on Steam, go out there, make a splash?' ... I'm like, 'You're kidding, right?' That made no sense at all at that time, but you know Valve stuck with it and they're in a really enviable position from all of that now. It still seems, probably crazy to me that they would be doing anything like that, you know, but, it's something that's not technically impossible, but would be really difficult from a market, sort of ecosystems standpoint." [1] https://www.youtube.com/watch?v=wt-iVFxgFWk#t=44m28s https://www.youtube.com/watch?v=wt-iVFxgFWk#t=44m28s
aantix 14y ago
Software development is usually about creating some sort of competitive advantage. And a fundamental tenant of competitive advantage is differentiation. Standard implementations/algorithms/patterns are commodities and are purposely so.
adastra 14y ago
I've gotten to know John a little bit, and I have to say it's a strange feeling to have a conversation with a person of his off-the-charts intelligence. I consider myself to be pretty smart-- was known as "the math whiz" in high school, went to top engineering universities and did very well there, have a couple of (minor) entrepreneurial accomplishments, etc. And yet talking to Carmack I feel like I'm talking to someone who is a full two standard deviations beyond me in raw intelligence horsepower. It's a pretty sobering and humbling experience. Part of it is that he really does spend 8+ hours per day coding, every weekday, and has done so for 20 years. You'd think his experience level there is about as high as you can get, so it's always cool to hear him talk about the new things he's still learning at his work. I have to wonder if there's anyone else in the world that has both his raw ability and all those man-years of programming experience. It seems like most successful technical people end up doing management and business. There's a couple of things people probably don't know about Carmack. For one, he can talk intelligently on a lot of different topics. A lot of nitty-gritty aerospace engineering, as well as the history of the space program and NASA for example. He's also up to speed on the latest across a wide range of technology, including things like cleantech. Second, he has a pretty good sense of humor and can be quite funny. Which is surprising I think just because he spends so little time (effectively zero) out being traditionally social, which you'd think would be necessary to getting good at making people laugh. But in conversation he has a pretty sense of comedy and timing. An example from his twitter feed that I clipped a while back: https://twitter.com/ID_AA_Carmack/status/167739644853747712 https://twitter.com/ID_AA_Carmack/status/167739644853747712 "Adding film grain, chromatic aberration, and rendering at 24 hz for film look is like putting horse shit in a car for the buggy experience."
iandanforth 14y ago
The quest for perfection may be futile. DNA is also code, and it's full of bugs. That code lives for hundred of thousands of years, if not millions. Biological processes offer the suggestion that your system can be functional in the face of constant failures and random variations in behavior. Biology can even offer a very high reliability rate. While we get sick all the time, and people are born with all sorts of genetically disadvantageous traits, many key processes are mind-bogglingly reliable. (No sight v No sense of touch: Compare the rates of blindness to the rates of congenital analgesia type 2) While the math behind CS offers tantalizing guarantees of reliability the reality of software development and developers deliver a reliability far lower. I think it is a fascinating thought experiment to imagine a development process where instead of writing any code, all you're writing is tests (or feature descriptions) and let the code adapt to the environment you've defined.
- CamperBob2 14y ago
  The quest for perfection may be futile. Agreed, and I think it's easy to observe that fact with nothing more than your DNA example. In biology, perfection will always be outcompeted by "good enough."
benthumb 14y ago
As much as I respect John Carmack, I have to say that I'm a little disappointed that he is rehashing this meme of software development not being a science... OK, wonderful, the state of the art in his shop doesn't rise to the level of being a consistently reproducible, measurable process, but that doesn't mean that this is a permanent condition or that its an insurmountable one.
- rapala 14y ago
  I didn't get the same impression that you got. To me, Carmack is saying that the biggest thing to focus is how to enforce the known best practices. That we need to understand the social aspects of software development well enough to reap the benefits of improvements in the engineering side. There is science involved in that, but it is mainly stuff from the social sciencies.

271 points by gb 14y ago

deleted 14y ago

[deleted]

pasbesoin 14y ago
For me, it stated that Javascript for Safari Mobile was turned off. Same result, though; remove two overlays -- one for the JS message, and another that simply masks the underlying content, and that underlying content is perfectly visible. I guess it's kind of pointless to comment, but I continue to resent the applicationization of basic content (data). In good part because it remains a security concern.
smspence 14y ago
...who cares? Do you have any thoughts or comments about the actual topic of the post? This is an article written by one of the most innovative, influential, and successful software developers in the world, giving a lot of interesting insights and thoughts on his craft. ...and you're concerned about the HTML/JS of some shitty wordpress template? We get it, you probably work in web development. Yes, poorly-coded websites exist. That's not what the content of the post is actually about. This is part of the decline in quality of Hacker News. When an article is posted, let's talk about the article, instead of pedantic off-topic garbage.
- deleted 14y ago
  [deleted]

cobrausn 14y ago

Running your code through static analysis can be eye-opening. And just like when you opened your eyes for the first time... you'll probably cry.

figglesonrails 14y ago
If I had a dollar for every time I saw this... if(obj == null && obj.isValid()) I'd have approximately 960 dollars per project.
- jabbernotty 14y ago
  > if(obj == null && obj.isValid()) Why would you encounter this (often)? It seems to me that this code would never evaluate to true.
  - mathgladiator 14y ago
    I hope he means > if (obj != null && obj.isValid()) { } Which is semantically correct due to the fail-fast evaluate of AND, it does require a double check since it's strange from a logic point of view. This is one the reasons that brace languages are hard to optimize since you can't commute things that ought to commute.
    - astrange 14y ago
      That statement can't be commuted because it expresses a concept that can't be commuted. If the two checks were independent (pure functions), it's not difficult for a compiler to determine that given enough program visibility.
  - arnsholt 14y ago
    It's a braino, I think. Instead of the right thing, which would be what mathgladiator posted below, this is a guaranteed null pointer exception when obj actually is null.
  - figglesonrails 14y ago
    This is Java code. If you test for a null reference AND THEN dereference it, you get a NullPointerException. The check was supposed to be "!= null". This check is obviously erroneous, and found via SCA. I was saying "if I had a dollar for every time I found this [via SCA] I'd have a lot of money."

VMG 14y ago

If he wrote a book about programming, I'd buy it in a heartbeat. Too bad that even he probably is still figuring everything out.

bsphil 14y ago
The more you know, the more you realize you don't know. That would be a great book though.
- K2h 14y ago
  I came to that same conclusion a few years ago. Sometime in college I was pretty happy, felt I was making good progression on real knowledge in a field. Now, a few years later - I'm not sure what I know is real and true, which are high order approximations, and which are flat out wrong, but still right enough to not cause too many problems. an example: in grade school you learn how to mix colors, primary colors with paints, etc. then a little later, in middle school you learn no.. for light based, its not the same type of addition. then a little later you learn there are like an infinite possible primary colors - then a little later you learn color is actually a frequency or combination of frequencies, and you start asking yourself if your friend detects these colors the same way you do. does red to you really look blue to your friend. it just gets weird.
  - lttlrck 14y ago
    love this example!
  - K2h 14y ago
    look what shows on HN today: negative frequency for light. things really do get weird. https://hackerne.ws/item?id=4429234 https://hackerne.ws/item?id=4429234
- whalesalad 14y ago
  Yep. Also, the smarter you are the more you tend to doubt yourself. Whereas less intelligent people tend to have more confidence in what they're doing. Bites me in the ass all the time.

figglesonrails 14y ago

Actually, I think one of his strongest points is about making mistakes -- everyone does them and everyone makes the most amateur of them. If you haven't tried running SCA on your code, try it sometime. I've got a ridiculous ego, but when you get hundreds of warnings on your code, you realize just how imperfect you can be and how impossible it is to be cognizant of all things at all times. This is why teams are almost always better, and I'd prefer to review and be reviewed by someone else -- I'm my own biggest blind spot.

musashibaka 14y ago

I would suggest watching his entire talk on youtube: http://www.youtube.com/watch?v=wt-iVFxgFWk http://www.youtube.com/watch?v=wt-iVFxgFWk

wwwtyro 14y ago
I was glued to the screen for the entirety of that talk. That guy is completely engrossing to listen to.
Keyframe 14y ago
Three and a half hours?? I better grab some popcorns then.
tkahn6 14y ago
Definitely worth watching. It's more like a tech talk than a keynote. Extremely good insight in there.

dllthomas 14y ago

The talk itself is well worth the 3 hours.

prawks 14y ago

I look forward to the QuakeCon keynote every year. Anyone who engineers software should really listen to Carmack. Also, this article's kind of silly... there's almost no discussion? Just watch the video. EDIT: I guess it's not so much an article as a sharing of info. Still. Watch the video.

pnathan 14y ago

One of the things I've been persuaded of is that software writing is fundamentally a non-scientific activity. Outside of the time and space constraints for a given subsystem, the craft of software is almost entirely subjective and limited only by mental capacities and flaws.

jcdavison 14y ago

i just finished the devbootcamp program so as a person who was thrown into oo programming with no real cs underpinnings, it is interesting to hear him talk about the social component . it is also pretty interesting to here him talk about making mistakes and the need to just get things done versus optimization.

nightski 14y ago

He is definitely right about the social aspect of software engineering. But I think he sells a lot of the tools short. For example, he brings up things like Monads, Lambda Calculus, and whatnot - but then immediately dismisses them as not affecting what one truly does. But I think this really misses the point. In our industry it is really easy to disguise oneself as a professional (or even just someone who knows what they are doing), without really knowing much of anything. Meaning, our focus as an industry has been on making the simple things as simple as possible (i.e. scripting/dynamic languages, code generation, frameworks). But what I see happening in the Haskell space for example (and even further in languages such as Agda) are attempts to distill things down to their elements. To find the true semantics behind a problem. This not only helps by producing cleaner and more readable code, but it also helps with communication. I really do believe software is a scientific (and mathematical) exercise. The problem is most of industry does not treat it as such, and hence we end up in the mess we are in.

rprospero 14y ago
While I love what Haskell has done for me as a programmer, I don't think that it's finding the true semantics behind our problems. I rather think that it's finding a different basis. To take an analogy, monads and lambda calculus are like Fourier series. For many classes of problems, they produce a cleaner, simpler understanding of the solution. I'd hate to try and solve a boundary value problem with just Taylor series. However, while expressing linear functions with Fourier series is possible, it's less clear than the Taylor series and you're more likely to mess it up. In the same way, monads, arrows, and recursion are great ways of describing many classes of programs. Additionally, they help with communication when your problem is a monad or an arrow. However, certain classes of problems are better described under other paradigms than being forced into the functional one. This comes back to Carmack's point. It's important to know Haskell, since it's distilled computation down to a set of elements which are useful for describing a large class of problems. Being able to communicate these solutions is important. However, other paradigms are less error prone and do communicate solutions more clearly on other classes of problems.
- nightski 14y ago

adjwilli 14y ago

I program mostly in Objective-C nowadays, but I started professionally with PHP. When I first started Objective-C, I found it really constricting in comparison. In PHP you can do things a thousand ways, most of the terrible. In Objective-C, specifically with Cocoa, things are a lot more rigid and prescribed. I found this frustrating, but love it now. It's made my PHP better too when I do occasionally go back. It forced me to think more about architecture. I also understand why my CS dept taught us Scheme first, not Java. To link that back to the post, this is the type of constriction he's talking about to make better programmers. Cocoa and Objective-C restricted me to only writing at least halfway decent code. With PHP, because of it's flexibility, you're free to get things done quickly, but in a terrible way. Sure with PHP you can do things right too, but it takes a lot more self-discipline and also a priori knowledge. Sorry to post yet another rag on PHP.

Androsynth 14y ago
Its not ragging when its constructive with a thoughtful argument.

HeyLaughingBoy 14y ago

With the NASA style development process, they can deliver very very low bug rates, but it’s at a very very low productivity rate I wonder how many non-developers understand this. I, along with the rest of my team, am trained in PSP (http://www.sei.cmu.edu/library/abstracts/reports/00tr022.cfm http://www.sei.cmu.edu/library/abstracts/reports/00tr022.cfm) and TSP (http://www.sei.cmu.edu/tsp/ http://www.sei.cmu.edu/tsp/) and we use it in our day-to-day development. It definitely helps us keep our defect rate below one bug/kLOC but it's an expensive process that results in very low LOC/day productivity. If very low shipped bug counts are very important to your organization, great. But most businesses these days seem to care more about having a usable product than they do a perfect (or close to it) product. Especially if it's on the Web where you can do multiple releases per day. As an industry, we really need to bear in mind that different business domains need radically different approaches to software engineering.

pnathan 14y ago
Can you follow up with some information about the (P|T)SP experience? I looked into it about a year ago and thought it was a ridiculous amount of overhead, and the blurbs about the initial data Humphrey used to create it was not persuasive. The "take our class" ads were not encouraging either. So if its working for you in actual development, I'd LOVE to hear more about what it does/doesn't do for you.
- HeyLaughingBoy 14y ago
  First, it helps to understand that even before moving to PSP/TSP, we were already in a process-heavy regulated Medical Device development environment, so it wasn't a big change. My understanding is that many teams starting with TSP didn't have much of a process to begin with. The good: PSP encourages a high level of developer responsibility for quality. So you use a checklist to review your code before running the unit tests. You record every defect you find and if applicable, use that information to make a better checklist. Every team has a TSP-trained Coach to guide the process, answer questions, and keep the team on track. The metrics generated from the process are analyzed weekly to see if the team is on target, if quality is where the predictions say it should be and if there are any roadblocks. The bad: it can be a major change to how you are used to working. The data collection, while as automated as possible, is annoying. The constant emphasis on tracking time on various stages of fixing a bug/adding a feature adds a noticeable amount of friction to your workflow. While it's not Waterfall, TSP is definitely not Agile. Its entire focus is on predictability of output. It's an attempt to take what works well for Manufacturing and apply some of that to software dev. In short, TSP/PSP is a good idea at heart for those types of development where initial product quality is critical or where you may never have a chance to fix a defect. This is not the case for most instances of modern software projects.

zxcvbn 14y ago

Richard Feynman wrote[1]: "We could, of course, use any notation we want; do not laugh at notations; invent them, they are powerful. In fact, mathematics is, to a large extent, invention of better notations. The whole idea of a four-vector, in fact, is an improvement in notation so that the transformations can be remembered easily." What he said about mathematics, I think it applies even more to programming. [1] The Feynman Lecture on Physics, Volume 1, Chapter 17

6ren 14y ago
At PARC we had a slogan: "Point of view is worth 80 IQ points." It was based on a few things from the past like how smart you had to be in Roman times to multiply two numbers together; only geniuses did it. We haven't gotten any smarter, we've just changed our representation system. We think better generally by inventing better representations; that's something that we as computer scientists recognize as one of the main things that we try to do. Alan Kay http://billkerr2.blogspot.com.au/2006/12/point-of-view-is-worth-80-iq-points.html http://billkerr2.blogspot.com.au/2006/12/point-of-view-is-wo...
- taybin 14y ago
  According to this, multiplication wasn't so bad: http://turner.faculty.swau.edu/mathematics/materialslibrary/roman/ http://turner.faculty.swau.edu/mathematics/materialslibrary/...
  - e12e 14y ago
    Without a table? Just from memory? I think I'd prefer decimal.
  - btilly 14y ago
    Actually real Romans did multiplication on an abacus. Reading from Roman numerals to/from an abacus is an incredibly natural operation. In Europe the disappearance of abacuses was directly tied to the rise of Arabic notation.

jberryman 14y ago

I don't want to be an ass, but this seems like a lot of vague contradictory rambling. Maybe I missed some big ideas in the parts I skimmed?

rapala 14y ago
I was also a bit confused. He said that stuff like monads are nice, but not that useful in the end. On the other hand, he seemed concerned about how to enforce best practices, to which I count monads in.

Arjuna 14y ago

Interesting comments on Mac and Linux platforms [1]: "Other interesting sort of PC-ish platforms, we have... the Mac still remains a viable platform for us. The Mac has never required any charity from id, all of those ports have carried their own weight there; they've been viable business platforms. I actually think that the Mac is going to become a little bit more important for us. Interestingly, we have a ton of people that use, like Macbooks at the office, but we don't have any really rabid, OS X fanboys at the company that drive us to go ahead and get the native ports out early. But, one of my pushes on the greater use of static analysis and verification technologies, is I pretty strongly suspect that the Clang LLVM sort of ecosystem that's living on OS X is going to be, I hope, fertile ground for a whole lot of analysis tools and we'll wind up benefiting by moving more of our platform continuously onto OS X just for that ability to take advantage of additional tools there. Linux is an issue that's taken a lot more currency with Valve announcing Steam for Linux, and that does change, factor, you know, changes things a bit, but we've made two forays into the Linux commercial market, most recently with Quake Live client, and, you know, that platform just hasn't carried its weight compared to the Mac on there. It's great that people are enthusiastic about it, but there's just not nearly as many people that are interested in paying for a game on the platform, and that just seems to be the reality. Valve will probably pull a bunch more people there. I know absolutely nothing about any Valve plans for console, Steam-box stuff on there; I can speculate without violating anything. One thing that also speaks to the favor of Linux and potential open source things is that the integrated graphics cards are getting better and better, and they really are good enough now. Intel's latest integrated graphics cards are good. The drivers still have issues. They're still certainly not going to blow away somebody's top of the line SLI system, but they are completely competent parts that are delivering pretty good performance. And one of the wonderful things is that Intel has been completely supportive of open source driver efforts, that they have chipset docs out there, and they work openly with community to develop that, and that's pretty wonderful. I mean, anybody that's a graphics guy, if you program to a graphics API, use D3D or OpenGL, you owe it to yourself at some point to go download the Intel chipset docs. There's hundreds of pages of them, but you really should read through and see what happens at the hardware level. It's not the same architecture that Invida and AMD have on there, but there's a lot of commonalities there. You'll grow as a graphics developer to know what happens down at the bit level. Another one of those things, if I had more time, if I could go ahead and clone myself a few times, I would love to be involved in working on optimizing the Intel open source drivers there. So, it's enticing, the thought there that you might have a well-supported, completely open platform that you could deliver content through the Steam ecosystem there. It's a tough sell on there, but Valve gets huge kudos for having the vision for what they did with Steam, sticking through all of it. It's funny talking about Doom 3, where we can remember back in the days when they're like, 'Well, should you ship Doom 3 on Steam, go out there, make a splash?' ... I'm like, 'You're kidding, right?' That made no sense at all at that time, but you know Valve stuck with it and they're in a really enviable position from all of that now. It still seems, probably crazy to me that they would be doing anything like that, you know, but, it's something that's not technically impossible, but would be really difficult from a market, sort of ecosystems standpoint." [1] https://www.youtube.com/watch?v=wt-iVFxgFWk#t=44m28s https://www.youtube.com/watch?v=wt-iVFxgFWk#t=44m28s

aantix 14y ago

Software development is usually about creating some sort of competitive advantage. And a fundamental tenant of competitive advantage is differentiation. Standard implementations/algorithms/patterns are commodities and are purposely so.

adastra 14y ago

I've gotten to know John a little bit, and I have to say it's a strange feeling to have a conversation with a person of his off-the-charts intelligence. I consider myself to be pretty smart-- was known as "the math whiz" in high school, went to top engineering universities and did very well there, have a couple of (minor) entrepreneurial accomplishments, etc. And yet talking to Carmack I feel like I'm talking to someone who is a full two standard deviations beyond me in raw intelligence horsepower. It's a pretty sobering and humbling experience. Part of it is that he really does spend 8+ hours per day coding, every weekday, and has done so for 20 years. You'd think his experience level there is about as high as you can get, so it's always cool to hear him talk about the new things he's still learning at his work. I have to wonder if there's anyone else in the world that has both his raw ability and all those man-years of programming experience. It seems like most successful technical people end up doing management and business. There's a couple of things people probably don't know about Carmack. For one, he can talk intelligently on a lot of different topics. A lot of nitty-gritty aerospace engineering, as well as the history of the space program and NASA for example. He's also up to speed on the latest across a wide range of technology, including things like cleantech. Second, he has a pretty good sense of humor and can be quite funny. Which is surprising I think just because he spends so little time (effectively zero) out being traditionally social, which you'd think would be necessary to getting good at making people laugh. But in conversation he has a pretty sense of comedy and timing. An example from his twitter feed that I clipped a while back: https://twitter.com/ID_AA_Carmack/status/167739644853747712 https://twitter.com/ID_AA_Carmack/status/167739644853747712 "Adding film grain, chromatic aberration, and rendering at 24 hz for film look is like putting horse shit in a car for the buggy experience."

iandanforth 14y ago

The quest for perfection may be futile. DNA is also code, and it's full of bugs. That code lives for hundred of thousands of years, if not millions. Biological processes offer the suggestion that your system can be functional in the face of constant failures and random variations in behavior. Biology can even offer a very high reliability rate. While we get sick all the time, and people are born with all sorts of genetically disadvantageous traits, many key processes are mind-bogglingly reliable. (No sight v No sense of touch: Compare the rates of blindness to the rates of congenital analgesia type 2) While the math behind CS offers tantalizing guarantees of reliability the reality of software development and developers deliver a reliability far lower. I think it is a fascinating thought experiment to imagine a development process where instead of writing any code, all you're writing is tests (or feature descriptions) and let the code adapt to the environment you've defined.

CamperBob2 14y ago
The quest for perfection may be futile. Agreed, and I think it's easy to observe that fact with nothing more than your DNA example. In biology, perfection will always be outcompeted by "good enough."

benthumb 14y ago

As much as I respect John Carmack, I have to say that I'm a little disappointed that he is rehashing this meme of software development not being a science... OK, wonderful, the state of the art in his shop doesn't rise to the level of being a consistently reproducible, measurable process, but that doesn't mean that this is a permanent condition or that its an insurmountable one.

rapala 14y ago
I didn't get the same impression that you got. To me, Carmack is saying that the biggest thing to focus is how to enforce the known best practices. That we need to understand the social aspects of software development well enough to reap the benefits of improvements in the engineering side. There is science involved in that, but it is mainly stuff from the social sciencies.