There's a line from the book "The Art of Software Testing" from Glenford Myers that has stuck in my head: "A successful test finds bugs".
In other words, you redefine success as "I found a bug". After all, if you test and don't find a bug, all you've done is waste time. You haven't improved the product. You haven't "proved correctness". The only way to improve the program is to find and fix bugs.
Since we're all driven to be successful, once you get into the mindset of "success is finding bugs" you will be astonished at how many bugs you find.
The Slashdot summary was really, really bad. They didn't pretend to be observing the earth from the moon, they analyzed the spectra of light passing through the earth's atmosphere and reflected off of the moon. The idea is that this is similar to analyzing the light passing through a planet's atmosphere as it transits in front of a star. So it's not as crazy as it sounds.
In any discussion about Open Source, it's appropriate to mentally substitute the verb "program" with the phrase "program or pay someone to program".
In any discussion of software, it's appropriate to mentally substitute the verb "program" with the phrase "program or pay someone to program". If you're willing to pay, you can always get what you want. "Open Source" has no bearing on that.
What's interesting here is that people talk a lot about how Open Source == freedom, not "free as in beer". But I'd be willing to be most posters asking about "Open Source" solutions to problems are more concerned with the "no cost" than they are with "I can modify the source".
And yet, dismal as the USA's space record is, it's miles ahead of any other nation on earth.
I wish people would stop acting like the sky is falling. It's not. Space is big. Really, really big. We're going to be exploring it for a long time. It's not the end of the world if we spend a couple of years researching new technologies rather than just building bigger firecrackers to get into orbit.
You can copy them as much as you like, install them as many times as you like, as long as you BOUGHT a copy. So just what do you object to? The need to actually pay for what you use?
People threaten to cancel all the time. Remember the "Left for Dead 2" boycott? People get up in arms over the craziest things. I'm sure WoW didn't lose even 0.01% of its subscriber base over this.
You invest your time and money in an MMO. We are typically talking about multi-year commtments of time...
Commitment is adopting a pet. Commitment is getting married. Commitment is joining the army. Playing an online video is playing an online video game. You're not "committing" to anything, you're not "investing" in anything. You're having fun. It's not like you're going to get a pension when you decide to move on from an MMO and do something else.
You would like to believe that the MMO in which you make such a huge investment is not run by retards who will, one day, make some colossal mistake that will sever you from the game.
You mean, a colossal mistake like ban you for hacking or some other naughtiness? Yup, they can do that. In fact, I guarantee you that at some point, that last WoW server will be turned off. Get used to the idea.
For god's sake, the whole "I was walking down the street and happened to intercept unecrypted wifi" argument is utterly ridiculous. No one "happens to intercept" wifi. You have to actively snoop. If you want a better analogy, try "I walked down the street and opened up people's mailboxes and read their letters. But they had it coming to them, they didn't have lockable mailboxes".
Google screwed up. Period. If they had simply done what they claim they wanted to do, and only recorded header information, this just wouldn't be an issue. If anyone else drove a fleet of vans around intercepting wifi, people on Slashdot would be going nuts, but because it's the cool company, all is forgiven.
This and similar "shouting out the window" analogies are just plain wrong. If I walk down the street past a dozen unsecured wifi networks, I don't hear or see anything. I have to be actively looking for unsecured wifi and then snooping in order to pick up anything. Enough with the bad analogies.
I love how people define "real gamers" as "people who play games exactly the way I do".
Guess what: I'm a "real gamer", I was in the SC2 beta, I was able to set up private games and invite my friends to play, and I don't give a damn whether SC2 has LAN play or not.
No, I wouldn't have that thought, because we in the USA have increased the space budget, cancelled the underfunded retread program to go to the moon, and have started focusing on the cool advanced space technologies that will propel humans to other planets.
It is not a strawman. Operators are overloaded all the time on Mathematics. Words are overloaded in human language. Why is overloading in a programming language so hard to accept?
Overloading numeric operators is a strawman. It's the obvious case where the operator works exactly as you expect. It's also the case that is already built into most language. How many times have you implemented a new numeric type?
As I pointed out, the operators for streams were chosen because they were obscure, because most of the operators had intuitive meanings that didn't match the overload. Which is the core problem with overloading operators.
But how is that different from C? If I add a pointer to a struct and make a copy of that struct somewhere in the code I have exactly the same issue.
Exactly the point: the difference in C++ the code doing a bitwise copy of the structure is automatically generated by the compiler, and not visible in the source code.
You mean you changed the class definition by adding pointers, without worrying about maintaining the class invariant (which is to protect those pointers) and blame the language? You might want to learn a bit more about OO programming.
When a change to the program can break a piece of code that the compiler conveniently wrote for me, yes, of course it's a language problem. Given the number of articles, web pages and C++ books that prominently mention workarounds for this issue, I'm clearly not alone in considering this to be a trap.
I'm sure you enjoy doing str.append("."); in your favorite language with no operator overloading at all. Even funnier must be 4 + 5 and 4.2.+ 5.3. Humans are, after all, context-free, and can't possibly use the surrounding code (i.e. the whole line, instead of a single token) to figure out what the code does.
Overloading numeric types is a nice strawman, and conveniently lets you ignore the stream operator issue that I mentioned. Well done.
Most people I know are aware that references are not smart pointers. Why would anyone think that? They are just like pointers that can't be changed. The only unusual usage is when you use them to keep temporary objects alive
Again ignoring the issue I brought up. I'll make it a little more explicit. Take a reference to an element of a vector. Add on to the vector until the vector is reallocated. The "reference" now points to garbage. No temporary objects involved. I can guarantee you that anyone familiar with other OO languages would be quite surprised by that behavior.
None of the things I cited (references being syntactic sugar on top of pointers, default assignment operator causing bugs, or the difficulty of coming up with decent overloaded operators) have anything to do with understanding OO. It's possible to be perfectly comfortable and good at object oriented programming, and still fall into a C++ trap. In fact, if you were comfortable with Java, you would certainly not expect a C++ reference to become invalid, just because you inserted another element into a container.
I spent a lot of years developing in C, some time in C++ (w/o using the standard template library) and the last year and a half using C++ with stl. So I think I have a pretty valid basis for comparison, and I'd say that C++ has far more ways to go wrong than C does. With C, you pretty much know what you've got. C++ has a number of subtle, nasty bear traps that can bite you. It's true that if you know what you are doing, you can produce good code & get the job done, but that's true of any language, including assembler.
Here's a couple of items off the top of my head:
Default assignment operator: All you need to do is add a pointer to your class and suddenly code that you don't see causes a bug. Yes, IF you know about this you can work around it. That's true of anything.
Overloaded operators: I was leafing through the original Stroustrup C++ book and found this paragraph about the stream output operator '<<': "But why <<?... The operators < and > were tried, but the meanings "less than" and "greater than" were so firmly implanted in people's minds that the new I/O statements were for all practical purposes unreadable."
Well, yes, when people see an operator, they "think" they know what it's doing. It's interesting to me that in this very first case of overloading, Stroustrup ran into this fundamental problem, and had to choose a somewhat obscure operator to get around it.
References: references aren't what most people think of as references. They are pointers with syntactic sugar. Try getting a reference to an element of a vector, and then doing something that causes the vector storage to be reallocation. Voila, you have a "reference" that refers to junk.
All of these aren't impossible problems. They are extra issues, inherent in the language, that you simply don't have in C. I think that C++ has a lot of interesting ideas, it has a lot of power, but ultimately it also has a LOT of problems.
Huh? If you wait 25 days (say) and then pay off your bill, they are loaning YOU money, not the other way around. You bought something and then had an interest-free loan of the cost of the item for most of a month.
No, he agrees that netbook growth has slowed. He just points out that the actual sales numbers indicate that this is due to customers opting for pricier, more powerful laptops, not downgrading to less powerful IPads.
So you pay $40 a month right now to do some web browsing, email, and videos, and you think the price won't go up when you don't have a local disk drive and every bit your computer processes comes through your network? I'd say $100 would be conservative.
Apple may well see the end of their premium profits and want to get into a different business. But that's their problem. It doesn't follow that everyone is going to rush to hand Steve the keys to the kingdom.
As far as hardware being a commodity, that's what it is right now. $300 - $500 gets the average person all the PC horsepower and storage that they need, and has done so for several years. I can't picture everyone trading that for hoping that their Internet connection is up. Just look at the reaction to Ubisoft demanding a constant Internet connection in order to play games.
That article starts with
"These scenarios are those involving multiple web sites running on a single server, via name-based or IP-based virtual hosts"
It sounds like this is talking about how to configure a single instance of Apache to serve up different websites based on the incoming IP address or the web site domain name. It doesn't sound like it applies to running multiple virtual machines, each of which has its own copy of Apache, each of which is trying to listen to port 80.
Although if I'm wrong, I'm sure someone will correct me.
How does it work for multiple copies of Apache to all be looking at port 80? I mean, from the outside world, there can only be one port 80 at that IP address, right?
Slashdot Mirror
And yet it works... get a reputation as a speed trap, people slow down, accidents go down.
There's a line from the book "The Art of Software Testing" from Glenford Myers that has stuck in my head: "A successful test finds bugs".
In other words, you redefine success as "I found a bug". After all, if you test and don't find a bug, all you've done is waste time. You haven't improved the product. You haven't "proved correctness". The only way to improve the program is to find and fix bugs.
Since we're all driven to be successful, once you get into the mindset of "success is finding bugs" you will be astonished at how many bugs you find.
Come wait with me in the book checkout line and tell me my Borders isn't doing well.
The Slashdot summary was really, really bad. They didn't pretend to be observing the earth from the moon, they analyzed the spectra of light passing through the earth's atmosphere and reflected off of the moon. The idea is that this is similar to analyzing the light passing through a planet's atmosphere as it transits in front of a star. So it's not as crazy as it sounds.
In any discussion of software, it's appropriate to mentally substitute the verb "program" with the phrase "program or pay someone to program". If you're willing to pay, you can always get what you want. "Open Source" has no bearing on that.
What's interesting here is that people talk a lot about how Open Source == freedom, not "free as in beer". But I'd be willing to be most posters asking about "Open Source" solutions to problems are more concerned with the "no cost" than they are with "I can modify the source".
And yet, dismal as the USA's space record is, it's miles ahead of any other nation on earth.
I wish people would stop acting like the sky is falling. It's not. Space is big. Really, really big. We're going to be exploring it for a long time. It's not the end of the world if we spend a couple of years researching new technologies rather than just building bigger firecrackers to get into orbit.
You can copy them as much as you like, install them as many times as you like, as long as you BOUGHT a copy. So just what do you object to? The need to actually pay for what you use?
People threaten to cancel all the time. Remember the "Left for Dead 2" boycott? People get up in arms over the craziest things. I'm sure WoW didn't lose even 0.01% of its subscriber base over this.
Commitment is adopting a pet. Commitment is getting married. Commitment is joining the army. Playing an online video is playing an online video game. You're not "committing" to anything, you're not "investing" in anything. You're having fun. It's not like you're going to get a pension when you decide to move on from an MMO and do something else.
You mean, a colossal mistake like ban you for hacking or some other naughtiness? Yup, they can do that. In fact, I guarantee you that at some point, that last WoW server will be turned off. Get used to the idea.
Yeah and for sure young people don't need insurance. I mean, no way you'd get hit by a car or anything.
For god's sake, the whole "I was walking down the street and happened to intercept unecrypted wifi" argument is utterly ridiculous. No one "happens to intercept" wifi. You have to actively snoop. If you want a better analogy, try "I walked down the street and opened up people's mailboxes and read their letters. But they had it coming to them, they didn't have lockable mailboxes".
Google screwed up. Period. If they had simply done what they claim they wanted to do, and only recorded header information, this just wouldn't be an issue. If anyone else drove a fleet of vans around intercepting wifi, people on Slashdot would be going nuts, but because it's the cool company, all is forgiven.
This and similar "shouting out the window" analogies are just plain wrong. If I walk down the street past a dozen unsecured wifi networks, I don't hear or see anything. I have to be actively looking for unsecured wifi and then snooping in order to pick up anything. Enough with the bad analogies.
I love how people define "real gamers" as "people who play games exactly the way I do".
Guess what: I'm a "real gamer", I was in the SC2 beta, I was able to set up private games and invite my friends to play, and I don't give a damn whether SC2 has LAN play or not.
No, I wouldn't have that thought, because we in the USA have increased the space budget, cancelled the underfunded retread program to go to the moon, and have started focusing on the cool advanced space technologies that will propel humans to other planets.
It is not a strawman. Operators are overloaded all the time on Mathematics. Words are overloaded in human language. Why is overloading in a programming language so hard to accept?
Overloading numeric operators is a strawman. It's the obvious case where the operator works exactly as you expect. It's also the case that is already built into most language. How many times have you implemented a new numeric type?
As I pointed out, the operators for streams were chosen because they were obscure, because most of the operators had intuitive meanings that didn't match the overload. Which is the core problem with overloading operators.
But how is that different from C? If I add a pointer to a struct and make a copy of that struct somewhere in the code I have exactly the same issue.
Exactly the point: the difference in C++ the code doing a bitwise copy of the structure is automatically generated by the compiler, and not visible in the source code.
You mean you changed the class definition by adding pointers, without worrying about maintaining the class invariant (which is to protect those pointers) and blame the language? You might want to learn a bit more about OO programming.
When a change to the program can break a piece of code that the compiler conveniently wrote for me, yes, of course it's a language problem. Given the number of articles, web pages and C++ books that prominently mention workarounds for this issue, I'm clearly not alone in considering this to be a trap.
I'm sure you enjoy doing str.append("."); in your favorite language with no operator overloading at all. Even funnier must be 4 + 5 and 4.2 .+ 5.3. Humans are, after all, context-free, and can't possibly use the surrounding code (i.e. the whole line, instead of a single token) to figure out what the code does.
Overloading numeric types is a nice strawman, and conveniently lets you ignore the stream operator issue that I mentioned. Well done.
Most people I know are aware that references are not smart pointers. Why would anyone think that? They are just like pointers that can't be changed. The only unusual usage is when you use them to keep temporary objects alive
Again ignoring the issue I brought up. I'll make it a little more explicit. Take a reference to an element of a vector. Add on to the vector until the vector is reallocated. The "reference" now points to garbage. No temporary objects involved. I can guarantee you that anyone familiar with other OO languages would be quite surprised by that behavior.
None of the things I cited (references being syntactic sugar on top of pointers, default assignment operator causing bugs, or the difficulty of coming up with decent overloaded operators) have anything to do with understanding OO. It's possible to be perfectly comfortable and good at object oriented programming, and still fall into a C++ trap. In fact, if you were comfortable with Java, you would certainly not expect a C++ reference to become invalid, just because you inserted another element into a container.
I spent a lot of years developing in C, some time in C++ (w/o using the standard template library) and the last year and a half using C++ with stl. So I think I have a pretty valid basis for comparison, and I'd say that C++ has far more ways to go wrong than C does. With C, you pretty much know what you've got. C++ has a number of subtle, nasty bear traps that can bite you. It's true that if you know what you are doing, you can produce good code & get the job done, but that's true of any language, including assembler.
... The operators < and > were tried, but the meanings "less than" and "greater than" were so firmly implanted in people's minds that the new I/O statements were for all practical purposes unreadable."
Here's a couple of items off the top of my head:
Default assignment operator: All you need to do is add a pointer to your class and suddenly code that you don't see causes a bug. Yes, IF you know about this you can work around it. That's true of anything.
Overloaded operators: I was leafing through the original Stroustrup C++ book and found this paragraph about the stream output operator '<<':
"But why <<?
Well, yes, when people see an operator, they "think" they know what it's doing. It's interesting to me that in this very first case of overloading, Stroustrup ran into this fundamental problem, and had to choose a somewhat obscure operator to get around it.
References: references aren't what most people think of as references. They are pointers with syntactic sugar. Try getting a reference to an element of a vector, and then doing something that causes the vector storage to be reallocation. Voila, you have a "reference" that refers to junk.
All of these aren't impossible problems. They are extra issues, inherent in the language, that you simply don't have in C. I think that C++ has a lot of interesting ideas, it has a lot of power, but ultimately it also has a LOT of problems.
Huh? If you wait 25 days (say) and then pay off your bill, they are loaning YOU money, not the other way around. You bought something and then had an interest-free loan of the cost of the item for most of a month.
No, he agrees that netbook growth has slowed. He just points out that the actual sales numbers indicate that this is due to customers opting for pricier, more powerful laptops, not downgrading to less powerful IPads.
So you pay $40 a month right now to do some web browsing, email, and videos, and you think the price won't go up when you don't have a local disk drive and every bit your computer processes comes through your network? I'd say $100 would be conservative.
Apple may well see the end of their premium profits and want to get into a different business. But that's their problem. It doesn't follow that everyone is going to rush to hand Steve the keys to the kingdom.
As far as hardware being a commodity, that's what it is right now. $300 - $500 gets the average person all the PC horsepower and storage that they need, and has done so for several years. I can't picture everyone trading that for hoping that their Internet connection is up. Just look at the reaction to Ubisoft demanding a constant Internet connection in order to play games.
Funny... I was going to say "ONLY six accounts?"
That article starts with "These scenarios are those involving multiple web sites running on a single server, via name-based or IP-based virtual hosts"
It sounds like this is talking about how to configure a single instance of Apache to serve up different websites based on the incoming IP address or the web site domain name. It doesn't sound like it applies to running multiple virtual machines, each of which has its own copy of Apache, each of which is trying to listen to port 80.
Although if I'm wrong, I'm sure someone will correct me.
How does it work for multiple copies of Apache to all be looking at port 80? I mean, from the outside world, there can only be one port 80 at that IP address, right?