jhdevos · HackerTrans

jhdevos

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9 yıl öncediscuss

> It looks as though cryptkeeper makes assumptions about encfs' command-line interface that are no longer valid.

This looks like a developer mistaking a command line interface for an API.

Unless an (interactive) CL interface is explicitly marked as being an API, and documented in such a way, and regression tests exist to make sure the interface remains backwards-compatible - you should never program against it. Ask for a proper API to access.

(edit: formatting)

10 yıl öncediscuss

This is explained in the article in a bit more detail. The point is not that the type system does something with the actual value - the point is that it would be impossible to create any code that results in such a value (other than null), since then you would have to provide an actual type that is somewhere between Integer and String - and that would obviously not pass the type checking. Using null avoids that.

Section 4.5 in the language spec deals with parameterized types; 4.5.1 deals with wildcards. Of course, there is no example in the specs that clearly points out what happens in this example - otherwise this wouldn't have remained undiscovered for so many years :)

If you can show, using the rules in the spec, that the sample program shouldn't pass type checking, then you'll have proved the article wrong :-)

10 yıl öncediscuss

I don't see the headline as misleading at all. There are two type systems in Java: the JVM's run-time type system, and Java's compile time type system. It's the latter that has been shown to be unsound. As the paper notes, it's fortunate that generics have been implemented with type erasure, because that is what saves the JVM from being unsound, too.

As for the problem itself: it really has nothing to do with inner classes (they are static in the example!). The problem is with this line:

    Constrain<U,? super T> constrain = null;

which leads the type system to assume that there is a type that is a superclass of T, which also is a subclass of B (from the 'Constrain' class) - even though no such type could possibly exist! The evil trick is in the 'null' - even though a type with the stated constraints is impossible, and so no actual 'real' value of this generic type could exist, 'null' is part of all types, so the compiler can't see the problem.

It really is a problem in the type system as defined in the standard, not just a compiler bug.

10 yıl öncediscuss

After interviewing many more and less experienced programmers (and asking most of them if they can explain a hash table - just for statistics!), I concur that most cannot.

There were quite some people that thought trees were faster than hash tables though - mostly the ones that had some incling of what a hash table does, but didn't know the entire picture. At least in all those cases I had the pleasure of educating them a little bit :-)

10 yıl öncediscuss

> First the law expressly forbids a patent on ideas.

Only in the sense that you can't forbid anyone else /having/ an idea, just that you can forbid them doing anything with it.

In software, it is definitely the idea that is protected, not the specific implementation - otherwise, copyright would be enough.

10 yıl öncediscuss

Of course, another question is: will the AI's consider us humans to have the equivalent of their consciousness? Or will they think "These humans don't not really possess consciousness, they just exhibit a crude biological simulation of it".

(BTW: This is not just meant as a joke, nor just as instigating fear of the singularity - turning a question on its head can sometimes lead to interesting insights).

11 yıl öncediscuss

Any idea what the best vim plugin for rtags is? I see there are several...

11 yıl öncediscuss

True - which is why they did the cream as well. At the very least, this study tells us that the mindfulness meditation is a 'more effective' placebo than the cream.

It's very hard do really do in a 'double blind' way - I would not be able to think of something that is to all appearances equal to the real mindfulness mediation, but actually only a fake. There's no substance to it.

Do you have any suggestions to do it better?

11 yıl öncediscuss

Yeah, the original Eternity puzzle (https://en.m.wikipedia.org/wiki/Eternity_puzzle) was a lot better in that regard - it spiked a whole online community focused on finding clever ways to find a solution, and was in fact solved within a year.

11 yıl öncediscuss

Integer overflow?

11 yıl öncediscuss

Having played on (and heard people play on) a pBone, I'd have to say that even though it's quite impressive to see what they've been able to do with just plastic, it's still quite some way off from being a 'quality' instrument.

And they do not prove at all that the same can be done for any kind of instrument: trumpets and trombones are a lot cheaper to make than things like bassoons - you can find very cheap brass trumpets on ebay for very little money, some of which are surprisingly acceptable; and a rather good trumpet will set you back quite a lot less than a basson only fit for a beginner.

11 yıl öncediscuss

That seems like a false sense of safety: when doing arithmetic, your program is most likely not going to be handling overflows correctly anyway. Also, when using unsigned ints, any code involving subtractions can lead to subtle bugs that only occur when one value is larger than another. I'd recommend sticking with signed ints for all arithmetic code.

11 yıl öncediscuss

In firefox: Preferences -> Advanced -> enable "Warn me when websites try to redirect or reload the page".

Other browsers will probably have similar options.

11 yıl öncediscuss

I think when smaller companies have patents, they tend to be closely related to their core business, and they have them precisely in order to use them 'offensively' - or, in other words, to protect their core business from companies that want to 'copy' them.

In principle, that is sort of what the patent system was intended for. (I still don't agree with it, but that's another story).

11 yıl öncediscuss

Wording is a bit sloppy: "Extending R (the inner while loop) takes at most a total of N steps, and positioning and testing each centers take a total of N steps too. Therefore, this algorithm guarantees to finish in at most 2*N steps, giving a linear time solution."

What he means is that the total time taken by ALL executions of the inner loop combined is at most N, not that each run of the inner loop takes at most N steps (otherwise it would become quadratic).

11 yıl öncediscuss

> Where can i find more information regarding this.

The C++ standard, of course :) But if you prefer some lighter reading, either http://www.cplusplus.com/reference/mutex/mutex/unlock/ or http://en.cppreference.com/w/cpp/thread/mutex/unlock explain what happens, in slightly different ways. I usually prefer the cppreference version, because it uses terminology from the standard more consistently, but there is no harm in reading multiple explanations about difficult concepts like these :)

I'd repeat the explanation here, but I think you'd best be served by reading one of the two links above.

12 yıl öncediscuss

> Will Windows run on it? Well... Yeah. Windows runs on everything powered by an x86 processor.

I've tried installing Windows 7 on an old Dell laptop a while ago. I got it working eventually, but had to hunt around for drivers for various things -- rather important things, like network, and video. In the end, I had to persuade some download site to give me the Windows XP drivers for the video card, and it worked with that (which, btw, is pretty awesome).

Of course, this is just anecdote, just like any story about Linux not working immediately on some modern laptop is -- but my experience is that these kinds of issues are much rarer than 10 years ago. Especially with Linux (with which I have most experience), but also with Windows.

12 yıl öncediscuss

A button to execute a single instruction would also be nice.

12 yıl öncediscuss

In fact, the animation draws attention away from the text, which you are probably supposed to read (otherwise, why bother with an alert). I really don't understand this infatuation with distracting unnecessary animations that people have nowadays...

12 yıl öncediscuss

No, we don't want that. A while ago there was even a headline here that boils down to 'Illegality will not be punishable'.

This was about people residing in the country illegally. Everyone understands the headline immediately, but it's still pretty ridiculous.