Hashes are just so useful. If I were among the group of people working on the C++ Standard Template Library I'd have stuck hashing containers in. Right now, things like hash_map are not a part of the official standard, BUT there are some good implementations out there. Supposedly, hashing containers are going to be in the next standard - hooray!
I hope the parent doesn't get modded down because it's actually insightful. Certainly humanoid robots would be useful, because monkey shaped robots are a good generalist shape. Not absolutely ideal for too many things, but really good enough for a whole lotta things.
But, sex will be one of the "killer apps" for robots. If you have any doubts, check out www.realdoll.com (NOT AT WORK - those robots look very very much like naked people). Even Asimov wrote in his books about people using robots for sex.
I use Linux for most of my work with WindowMaker, except when I'm at a client site. Right now I'm using an NT box and Exceed to work on a 4 processor AIX box. I carry AIX compiled GNU utilities whereever I go, and a tiny window manager called gwm. It does all I want or need: xterms and a virtual desktop, in 500K.
If you've got a really dinky box, I can recommend WindowMaker. If your machine is really REALLY dinky, then use something even lighter than that. Not a hard decision.
I used to invoke mutt with a script that sent a complaint message to abuse@postmastergeneral.com every time I read my e-mail.
They claimed that all their lists were opt-in, but actually they had no idea. They accepted lists from their customers and took their word that they were opt-in. They would happily remove you from their mailing lists, but the next customer that submitted a list that included your name would automatically re-add your name.
So, the perfect solution to me was to simply complain about all the goddamn spam regardless of whether I had received any or not. That would remove my name from all their mailing lists *for that day*. It solved my problem completely. I don't give a fuck about whatever problems I might have caused for them.
When the Canadians heard that the North Pole was going to the Russians, there was a tremendous public outcry. To resolve the problem, the judges have announced that the North Pole will be awarded to BOTH the Russians and the Canadians. The Russians are justifiably pissed. They say that the meaning of the North Pole will be diminished if there are two of them.
I think it was a posting of Scientology's OT-III. Apparently they were afraid that too many people would find out that it's just a really bad science fiction story.
The Oracle in the Matrix was a bit like the Oracle at Delphi. She sat on a stool, she baked funny cookies ("I promise you that by the time you're finished eating it, you'll feel right as rain." You can say THAT again) and she foretold the future in ambiguous terms.
The asteroid was spotted only after it passed us. If we knew the trajectory of the asteroid, then we would have been able to calculate that it would miss us. If the asteroid was going to hit us, then depending on how far out, they might be able to guess which ocean it would fall into, or which continent might get hit.
If you are prepared to sit next to it managing it's input and output(ie tapes) it could anything up with out an overflow.
Then you're not talking about a Sinclair. You're effectively saying that the combination of a tape feeder monkey AND a Sinclair are a turing machine. That's quite a bit different than just a Sinclair.
A Turing machine doesn't need to hold an initial set, that's on the tape
The tape is defined as part of the turing machine. A Turing machine without a tape is just an automaton
I'm not sure that I'm getting that this across.
Yes, you are. You're adding all sorts of hardware to the sinclair to make it more capable, but remember that even a sinclair with a googalplex bytes of memory is infinitely smaller than the tape on a Turing machine.
Let me help you out:
Given that you have a Sinclair programmed to emulate JUST the read/write head, you also need to have an INFINITELY long mag tape to store the initial program/dataset and hold the result of the computation.
Only that will make a machine equal to a Turing machine, nothing else. A Sinclair by itself is not equivalent. That infinite tape is very important.
To give you an insight into the different, let's consider the halting problem. It's impossible to write a program that can determine if a Turing machine will ever stop running. BUT, I can easily imagine a program that can tell you if a Sinclair will ever stop running.
Step by step:
1) A sinclair has a finite memory (1K?) and a finite number of processor registers and states. If one desired, one could enumerate them all, from 1 to N.
2) Now, we know how many states a Sinclair has. We also know how quickly the machine changes states (the clock speed).
3) The only thing else that we need is a computer larger than the Sinclair, large enough to hold all possible states of the Sinclair. That larger computer has access to the complete state of the Sinclair computer.
4) We load the Sinclair with our mystery program. Does it stop or not? We will soon know the answer.
5) At every clock cycle, the larger computer stores away the complete state of the Sinclair computer.
6) The larger computer also checks the just stored state of the Sinclair computer against all the past states that have already been observed. If there is a match, that means that the Sinclair is in exactly the same state that it was in sometime during the past. Therefore, the Sinclair is in an infinite loop and will never stop.
7) Since we know how many possible states the Sinclair could be in. We also know the clock speed of the Sinclair. Therefore, we know what the maximum run time of the Sinclair is without ever duplicating the state of the machine.
8) So, with the information from #7, we can positively say that if a duplicate state is not detected (as in #6) then the Sinclair's program will eventually halt.
So, there's the proof. The halting problem is impossible to solve on a Turing machine. I have just solved it for a Sinclair, therefore, a Sinclair is not a Turing machine.
Add the infinite tape to the Sinclair and it WILL be a Turing machine. (If you can find an infinite tape I will buy it from you for a million dollars.)
Can the sinclair add up so many numbers that it overflows? Can the sinclair add two billion digit numbers? It can't hold the two starting numbers, and it can't hold the sum.
No, because the problem statement could be larger than the computer. For example, I might have a billion random numbers to add up. The sinclair could not hold the beginning data set, nor could it compute the dataset from a smaller function.
Not necessarily. Turing machines do not exist in real life, because they are necessarily infinite machines. A Sinclair has just a measly amount of memory. A Turing machine could compute anything a Sinclair could, but not the other way around.
I can imagine that there are those out there salivating at the prospect of showing a character using a product and then providing an interaction - "Would you like a (product) right now? Just click yes." That's evil.
What I really want to do is to use this to make the shows I watch much better. For example, in Voyager if Capt. Janeway starts to say something like "the Prime Directive could be a problem here" I want the program to pop up a screen asking me if I want her to ignore the damn directive. That would be good.
Unless you're using a good programming language which frees the programmer to concentrate on solving the problem rather than worrying about the minutiae.
Ahhh, the True Scotsman fallacy. A short demonstration:
Man #1: I'm a Scotsman! Man #2: Do you eat haggis? Man #1: No, I hate haggis. Man #2: Then you're not REALLY a Scotsman.
Your statement that Hitler was not really a Christian is the same as the statement that Man #1 is not really a Scotsman. Hitler made it quite clear in his writings that he was a Christian, and that he saw himself as doing god's work.
The Christian religion, is one of the primary reasons for the development of Europe to where it is today.
That's a laughable statement. Development of Europe was held back by an oppressive religious government, and only really started when secularism took hold. Obviously your grasp of history is completely unbased.
#1: The Boehm collector can work the way you described, and works very well that way. BUT, you can specify options to the collector that disable that, or limit that behavior. Using the collector this way doesn't slow the program down.
#2: Conservative collectors DO leak. That's part of their nature. But, the leak characteristics are entirely different. Leaks introduced by a human tend to grow until the program runs out of memory completely. Leaks introduced by a conservative collector grow in a bounded fashion, typically 2x the amount of memory required by a perfectly leak-free system. This "bounded leak" characteristic is not necessarily a bad thing, since it gives the safety of a garbage collector and the ability to plan an appropriate memory size for a server.
You're right that GC is a "hack", but it works pretty damn well, and it can make a difference between a million line program that leaks like hell and crashes all the time, or a million line program that runs and doesn't crash.
You're also right that the language isn't really meant to be garbage collected. I would like to see a "gc" keyword in a future language spec to provide support for an (optional) garbage collector.
You want to talk slow and hideous? I'm debugging a program (I didn't write it) that's 400000 lines which could have used a good collector. Instead, the thing has extremely poor control over its memory, and that defeats the purpose of using a COMPUTER in the first place.
We nearly never have merge problems. It is standard procedure that people keep their tree up-to-date with the cvs tree, and thus conflicts rarely arrise
I'll second this: At many companies I have heard over and over that CVS sucks because of the conflicts. When I inquire further, I find out that people never or rarely use the cvs update command to synchronize. cvs update should be executed almost like a nervous habit, or at least a couple times a day. More if code is being checked in frequently, or if you are working on the same code as someone else. Use the watch commands in cvs to be notified when others edit your files.
It's a shame, really, because programmers seem to be afraid of cvs, preferring a more primitive tool such as rcs or pvcs. cvs lets programmers work in the style that is most natural in an open-source arrangement, and in my opinion can be a far more productive environment than a systems that locks the rest of the team out of critical files.
Slashdot Mirror
If you're sorting a very short list, like 10 items, a bubble sort will be all done by the time a quicksort is just getting set up.
Hashes are just so useful. If I were among the group of people working on the C++ Standard Template Library I'd have stuck hashing containers in. Right now, things like hash_map are not a part of the official standard, BUT there are some good implementations out there. Supposedly, hashing containers are going to be in the next standard - hooray!
I hope the parent doesn't get modded down because it's actually insightful. Certainly humanoid robots would be useful, because monkey shaped robots are a good generalist shape. Not absolutely ideal for too many things, but really good enough for a whole lotta things.
But, sex will be one of the "killer apps" for robots. If you have any doubts, check out www.realdoll.com (NOT AT WORK - those robots look very very much like naked people). Even Asimov wrote in his books about people using robots for sex.
Who's that Belgian that pied Bill Gates? Certainly Slashdot could scape together enough cash to hire that guy to pie Canter.
I say we kill him.
No, first we drown him, them we kill him.
NO, first we shoot him, THEN we drown him, then we kill him.
(Canter, in an imitation of Pee Wee Herman's voice) I say you give him to me!
As an American, I find YOU offensive. Not Indians, YOU. Your generalisms make you sound prejudiced.
I use Linux for most of my work with WindowMaker, except when I'm at a client site. Right now I'm using an NT box and Exceed to work on a 4 processor AIX box. I carry AIX compiled GNU utilities whereever I go, and a tiny window manager called gwm. It does all I want or need: xterms and a virtual desktop, in 500K.
If you've got a really dinky box, I can recommend WindowMaker. If your machine is really REALLY dinky, then use something even lighter than that. Not a hard decision.
That one is already in your mailbox, with Ed MacMahon's picture on it.
I used to invoke mutt with a script that sent a complaint message to abuse@postmastergeneral.com every time I read my e-mail.
They claimed that all their lists were opt-in, but actually they had no idea. They accepted lists from their customers and took their word that they were opt-in. They would happily remove you from their mailing lists, but the next customer that submitted a list that included your name would automatically re-add your name.
So, the perfect solution to me was to simply complain about all the goddamn spam regardless of whether I had received any or not. That would remove my name from all their mailing lists *for that day*. It solved my problem completely. I don't give a fuck about whatever problems I might have caused for them.
When the Canadians heard that the North Pole was going to the Russians, there was a tremendous public outcry. To resolve the problem, the judges have announced that the North Pole will be awarded to BOTH the Russians and the Canadians. The Russians are justifiably pissed. They say that the meaning of the North Pole will be diminished if there are two of them.
I think it was a posting of Scientology's OT-III. Apparently they were afraid that too many people would find out that it's just a really bad science fiction story.
The Oracle in the Matrix was a bit like the Oracle at Delphi. She sat on a stool, she baked funny cookies ("I promise you that by the time you're finished eating it, you'll feel right as rain." You can say THAT again) and she foretold the future in ambiguous terms.
They're even going to show Revolution OS on the big screen. How many theaters in your town did that?
The asteroid was spotted only after it passed us. If we knew the trajectory of the asteroid, then we would have been able to calculate that it would miss us. If the asteroid was going to hit us, then depending on how far out, they might be able to guess which ocean it would fall into, or which continent might get hit.
If you are prepared to sit next to it managing it's input and output(ie tapes) it could anything up with out an overflow.
Then you're not talking about a Sinclair. You're effectively saying that the combination of a tape feeder monkey AND a Sinclair are a turing machine. That's quite a bit different than just a Sinclair.
A Turing machine doesn't need to hold an initial set, that's on the tape
The tape is defined as part of the turing machine. A Turing machine without a tape is just an automaton
I'm not sure that I'm getting that this across.
Yes, you are. You're adding all sorts of hardware to the sinclair to make it more capable, but remember that even a sinclair with a googalplex bytes of memory is infinitely smaller than the tape on a Turing machine.
Let me help you out:
Given that you have a Sinclair programmed to emulate JUST the read/write head, you also need to have an INFINITELY long mag tape to store the initial program/dataset and hold the result of the computation.
Only that will make a machine equal to a Turing machine, nothing else. A Sinclair by itself is not equivalent. That infinite tape is very important.
To give you an insight into the different, let's consider the halting problem. It's impossible to write a program that can determine if a Turing machine will ever stop running. BUT, I can easily imagine a program that can tell you if a Sinclair will ever stop running.
Step by step:
1) A sinclair has a finite memory (1K?) and a finite number of processor registers and states. If one desired, one could enumerate them all, from 1 to N.
2) Now, we know how many states a Sinclair has. We also know how quickly the machine changes states (the clock speed).
3) The only thing else that we need is a computer larger than the Sinclair, large enough to hold all possible states of the Sinclair. That larger computer has access to the complete state of the Sinclair computer.
4) We load the Sinclair with our mystery program. Does it stop or not? We will soon know the answer.
5) At every clock cycle, the larger computer stores away the complete state of the Sinclair computer.
6) The larger computer also checks the just stored state of the Sinclair computer against all the past states that have already been observed. If there is a match, that means that the Sinclair is in exactly the same state that it was in sometime during the past. Therefore, the Sinclair is in an infinite loop and will never stop.
7) Since we know how many possible states the Sinclair could be in. We also know the clock speed of the Sinclair. Therefore, we know what the maximum run time of the Sinclair is without ever duplicating the state of the machine.
8) So, with the information from #7, we can positively say that if a duplicate state is not detected (as in #6) then the Sinclair's program will eventually halt.
So, there's the proof. The halting problem is impossible to solve on a Turing machine. I have just solved it for a Sinclair, therefore, a Sinclair is not a Turing machine.
Add the infinite tape to the Sinclair and it WILL be a Turing machine. (If you can find an infinite tape I will buy it from you for a million dollars.)
Can the sinclair add up so many numbers that it overflows? Can the sinclair add two billion digit numbers? It can't hold the two starting numbers, and it can't hold the sum.
A Turing machine is a machine that uses a tape, a read/write head, and a set of rules to solve an equation.
... x1000000000000)
The equation that I wish to solve has a trillion arguments:
f(x1, x2, x3,
The turing machine sets up the arguments on the tape.
It is quite clear that a Sinclair is not a Turing machine. Turing machines are infinite, Sinclairs are finite.
No, because the problem statement could be larger than the computer. For example, I might have a billion random numbers to add up. The sinclair could not hold the beginning data set, nor could it compute the dataset from a smaller function.
Not necessarily. Turing machines do not exist in real life, because they are necessarily infinite machines. A Sinclair has just a measly amount of memory. A Turing machine could compute anything a Sinclair could, but not the other way around.
I can imagine that there are those out there salivating at the prospect of showing a character using a product and then providing an interaction - "Would you like a (product) right now? Just click yes." That's evil.
What I really want to do is to use this to make the shows I watch much better. For example, in Voyager if Capt. Janeway starts to say something like "the Prime Directive could be a problem here" I want the program to pop up a screen asking me if I want her to ignore the damn directive. That would be good.
Unless you're using a good programming language which frees the programmer to concentrate on solving the problem rather than worrying about the minutiae.
And in a hundred years I hope we have one.
Ahhh, the True Scotsman fallacy. A short demonstration:
Man #1: I'm a Scotsman!
Man #2: Do you eat haggis?
Man #1: No, I hate haggis.
Man #2: Then you're not REALLY a Scotsman.
Your statement that Hitler was not really a Christian is the same as the statement that Man #1 is not really a Scotsman. Hitler made it quite clear in his writings that he was a Christian, and that he saw himself as doing god's work.
The Christian religion, is one of the primary reasons for the development of Europe to where it is today.
That's a laughable statement. Development of Europe was held back by an oppressive religious government, and only really started when secularism took hold. Obviously your grasp of history is completely unbased.
If this doesn't suck, I don't know what does
Memory leaks?
As to your arguments:
#1: The Boehm collector can work the way you described, and works very well that way. BUT, you can specify options to the collector that disable that, or limit that behavior. Using the collector this way doesn't slow the program down.
#2: Conservative collectors DO leak. That's part of their nature. But, the leak characteristics are entirely different. Leaks introduced by a human tend to grow until the program runs out of memory completely. Leaks introduced by a conservative collector grow in a bounded fashion, typically 2x the amount of memory required by a perfectly leak-free system. This "bounded leak" characteristic is not necessarily a bad thing, since it gives the safety of a garbage collector and the ability to plan an appropriate memory size for a server.
You're right that GC is a "hack", but it works pretty damn well, and it can make a difference between a million line program that leaks like hell and crashes all the time, or a million line program that runs and doesn't crash.
You're also right that the language isn't really meant to be garbage collected. I would like to see a "gc" keyword in a future language spec to provide support for an (optional) garbage collector.
You want to talk slow and hideous? I'm debugging a program (I didn't write it) that's 400000 lines which could have used a good collector. Instead, the thing has extremely poor control over its memory, and that defeats the purpose of using a COMPUTER in the first place.
We nearly never have merge problems. It is standard procedure that people keep their tree up-to-date with the cvs tree, and thus conflicts rarely arrise
I'll second this: At many companies I have heard over and over that CVS sucks because of the conflicts. When I inquire further, I find out that people never or rarely use the cvs update command to synchronize. cvs update should be executed almost like a nervous habit, or at least a couple times a day. More if code is being checked in frequently, or if you are working on the same code as someone else. Use the watch commands in cvs to be notified when others edit your files.
It's a shame, really, because programmers seem to be afraid of cvs, preferring a more primitive tool such as rcs or pvcs. cvs lets programmers work in the style that is most natural in an open-source arrangement, and in my opinion can be a far more productive environment than a systems that locks the rest of the team out of critical files.