skysight-inc/HackerNews huggingface dataset:
Heh, not quite.

Treat objects and arrows abstractly like you're building a graph. Actual meaning can be applied later. A category is thus a set (or proper class) of objects, O, and a set (or proper class) of arrows, A along with two mappings dom and cod from A -> O. The laws are first that for any object (o in O) there exists an arrow (id(o) in A) such that dom(id(o)) = o and cod(id(o)) = o and second that if you have two arrows (f, g in A) such that cod(f) = dom(g) then there is defined their composition (compose(f,g) in A) such that dom(compose(f,g)) = dom(f) and cod(compose(f,g)) = cod(g).

You can draw all that as the objects and arrows and things these slides display. So far this just gives you a graph-like structure.

The "category laws" ensure coherence of the category and state that (compose(f, id(x)) = f) when defined, (compose(id(x), g) = g) when defined, and that compose is associative. From an abstract algebraic POV this is almost like saying that A is a monoid which ought to (correctly) suggest that most of the interesting structure of a category is carried by the arrows.

Now, if you want to talk about specific categories you can do what you were doing. For instance, the category of sets, Set, is the category where you take O to be the proper class of all sets and A to be the functions between them. Immediately, you'll find that dom(.)/cod(.) are the domain and codomain of your functions, id(.) locates the identity function on a set, and compose(.,.) composes functions.

As a more interesting example you could consider Grp the category where O is all groups and A is all group homomorphisms. This is a subcategory of Set obviously and it also comes with much more interesting structure. For instance, an important category theoretic statement about Grp is that Grp has a "zero object", which is to say that (a) there exists an object init such that there is a unique arrow from init to any other object, (b) there exists an object fin such that there is a unique arrow from any other object to fin, and (c) init = fin.

http://en.wikipedia.org/wiki/Zero_object_%28algebra%29
Ah, the joys of learning math from slides without the talk the slides were helpers to.

The objects here are not necessarily sets, and the arrows are not necessarily functions -- this is actually one of the points of category theory, to abstract the notion of morphism away from set theory. This becomes necessary, when in your regular mathematical life you encounter morphisms which are not strictly functions, but nevertheless in many ways behave as such. Best example would be the homotopy classes of maps between topological spaces. Homotopy classes do not map points from domain space to codomain space, but nevertheless you can compose them, there's a homotopy class of identity, which acts as an identity on composition, sometimes there are homotopy classes that are inverses and so on.

If this sounds complicated and unnatural, that's because it is: it is pointless to learn category theory before learning where and how it is useful. This is completely opposite order than in which it was conceived, and totally misses the purpose the category theory, which is to make everything clearer, to reduce the number of notions, to make it easier to notice analogous behavior between separate concepts, to reduce number of repeating arguments. Learning what a morphism or functor or natural transformation is, without having tens of examples of these notions, only increases the number of concepts without a corresponding increase in understanding.

My advice is, if you want to learn category theory, learn algebraic topology first, or at least abstract algebra (groups, rings, modules, fields). Otherwise, you'll see very little purpose, and very little use.
How to Turn Your Inbox into a Mini University
Continuous Delivery in a Hostile Environment [video]
'Smart trousers' could replace wheelchairs
Same here.

Also, if nut allergies were unheard of in the EU.. why would nut-allergy news be on the BBC's front page?
"Markets" only work when there is a seller, and neither helium nor tuna have a seller.

The price of Tuna is set of "how expensive is it to produce a can of tuna" rather than "how many tuna are left in the ocean".
In fact, the lower the production cost of tuna fishing, the higher the risk that we empty the ocean of all the tuna.

It's really a problem of the Tragedy of the commons. There is no cost of tuna in the ocean, except the cost of fishing it. So it's a commons, and it will be overexploited.

http://en.wikipedia.org/wiki/Tragedy_of_the_commons

also: be sure to understand
http://en.wikipedia.org/wiki/Collapse_of_the_Atlantic_northw...
That debt isn't new, but is instead just a formalization of an arrangement that goes back to antiquity--each child is born with the obligation to take care of his or her parents when they get old.
If anybody's interested, here's a petition against evictions of boat dwellers:

https://you.38degrees.org.uk/petitions/boats-are-homes-preve...
I agree, but the issue is with a post where someone apparently claims to be getting such results right now.
How does one run a reputation system without knowing whose reputation one is calculating?
I scanned through the first 50 slides or so. I've read and drawn out the first few chapters to myself of "Categories for the Working Mathematician", so for me - this was a very nice presentation that graphically illustrated the key forms and key semantics.

I look forward to reading the code parts.

But I have to agree with other posters - it took a lot of studying to get to the point where I can understand your slides. I think by the time you can read mathematics like this, it is because you already understand it verbosely.

As for people who don't agree that this is for beginners, I don't think you will be able to feel like you get it until you sit down with the work and stare at it a lot until it makes sense to you. It sounds stupid and silly, but that's the only way I can really communicate how to learn this stuff with a feeling of adequate understanding. The simplicity and elegance of the pictures do not adequately convey how difficult this stuff is to comprehend, especially if your mathematical foundation involves reasoning about real things. It is descriptive of abstract layers of terms, and the relationships they construct. Category theory is essentially the math of maths.
WebDAV for retrieval is just HTTP GET right?
> The capability of decentralisation in Bitcoin is important because it acts as a safeguard against forced centralisation and coercion. As long as the capability remains, whether or not people for practical/efficiency reasons opts for centralisation ought not cause most anarchists any major concern.

I'm probably misunderstanding something, but isn't it more that blockchain technology allows decentralisation, while dominance of any particular deployment supports centralisation? As I understand it, once Bitcoin is centralised, the 51% can control it as they wish, and the only alternative is to set up a wholly separate Bitcoin2 chain, or another altcoin.

(Again resulting in cryptocurrency being a bad store of value.)
At my job, where I am a tester, "number of bugs" is one of the most prominent metrics in our evaluation.
I have tried to talk 3 of my bosses out of that (2 of which are engineers, one of them has a masters degree in some area of computing), but to no avail.
Sigh...

OP: Do NOT use bug count, for all that is holy.
Algorithms and computers won’t stop terrorism
why the jump from 193nm light to 13.5nm light with nothing in between? Would 50nm light for instance basically be exactly as hard as 13.5nm so you just go with the smallest possible?
Mystery drones spotted flying over Paris
What?
There is a strong bias against hiring women. Read about it and steps to reduce it here:

http://geekfeminism.wikia.com/wiki/Reducing_male_bias_in_hir...

Everyone (including women) is biased against hiring women in tech. Even if it is tiny, why wouldn't you take steps to reduce your own bias?
Even if "the pipeline is the problem", why wouldn't you take all possible steps to reduce the bias at your stage of the pipeline?
They are arrows. Arrows and objects are the primitives of category theory, just like sets and set membership are the primitives of set theories (well most of them anyway).

A category that captures the notion of sets and maps can be described in terms of arrows, objects and some semantic rules about which arrows (here interpreted as maps) connect which objects (here interpreted as sets).

Wiki on the "Category of sets [and maps]" -> http://en.wikipedia.org/wiki/Category_of_sets

Other rules about arrows between objects describe categories that capture other mathematical concepts.
Very interesting writeup, thanks!
Mr. Eich explained it here: http://www.quora.com/Did-JavaScript-evolve-from-another-prod...

"Lloyd [Tabb] and Bill [Turpin] made suggestions such as too-loose implicit conversions for the == operator, and the String.prototype.link/bold/blink/etc. HTML formatting methods. My fault for taking these, they were mistakes."
I've lived in several of these cities briefly (Seattle, Austin), and a long-term (Raleigh, NYC).

If you can put up with the car culture - which you have to if you want to live outside of NYC or Chicago - Raleigh is a great city. Very low cost of living, a burgeoning downtown night-life and cultural scene, and very warm, likable people. Austin has a much better downtown, but I'd be concerned about traffic moving there, which is not a problem (yet) for Raleigh.
Glassdoor suggests "software developers" or "software engineers" in London earn around $60k, which would put it far below the salaries listed here.

In the absence of the COL index for the UK we can use the "London living wage" - supposedly a baseline for a minimum acceptable standard of living[1] which translates to £18k (a little under $30k).
The tax paid on the amount earned in excess of this living wage is around £7k (<$11k)
That would leave around $19k of savings or "discretionary spending", actually slightly better than NYC and Portland despite the low salary, but based on what is almost certainly a much less generous view of essential costs of living.

[1]Since it assumes dependents it's quite a generous minimum standard; indeed excluding tax payments from the equation I've never spent more than it whilst living in London on substantially higher income. But it's also almost certainly less generous than the COL assumptions for the US cities.
Indeed, I thought it was a minimal version of Bart's Preinstalled Environment (BartPE) ...
The U.S. government is selling large quantities of helium at below market prices, apparently (though I'm not sure what a below market price is...if they are willing to keep selling at that price doesn't it become the market price?).
Exactly, proof that they store them in plaintext would be sending the old one via email, if it is a new one it may not be stored in plain, just generated stored hashed/whatever and sent in plaintext, and yes I do agree it is not a good idea
What Is Web-Scale IT and Why Does It Matter to Us Mortals?
I grew up in St. Albert, just outside of Edmonton and slid my way to school many times. Making some sort of official 'freezeway' seems like an obvious evolution and concentration of something people do a lot of anyway! (In boots, mind you...)
Yeah, transistor size might reach their top pretty soon, but with 3D circuits and new materials speeds will continue to increase.

I would bet that improvements will become less predictable, though. Unfortunately, investors really dislike unpredictability, so R&D spending will probably drop.
Correct, but some people are rejecting every conspiracy theory on the sole ground that it assumes conspiracy, and this heuristic is not critical thinking.
In a lot of places even 1 million isn't a decent house, once you try and accommodate kids.

If you consider sqft of home/land, amenities and distance to highly rated schools, Austin can be 10x less expensive, and it's easy to show examples of this.
New community to write and discuss code with fellow programmers
My gut feeling is that the plane was accidentally shot down as part of the continuing tensions in the South China Sea. This article and the included map illustrate the problems quite well:

http://www.bbc.com/news/world-asia-pacific-13748349

There were a large number of different nations involved in various "war games", "search and rescue practices", and general provocative actions at the time. http://tass.ru/en/world/725908
It is very much about polymorphism and generics.
There are many studies on pesticide toxicity, but you can't really set the bar so high as to ask for the kind of double-blind human studies you would use for new drugs.

In most cases such studies would simply be unethical, you can't just intentionally expose people to chemical you suspect might be harmful in studies.
> But the culture of business doesn't have any innate hormonal path, so why should it conform to mens' hormones and not women's? Why can't we change the realities of STEM to create a balance?

"Business" is far different from the realities of mechanical engineering, industrial engineering, etc -- which go from very specific courses in education to certain work environments.

For example, take children of age ~7. Boys love playing with cars; girls do like them a bit too, but it's pretty clear they prefer simulating social interactions, specially dolls talking. Should we address this imbalance too? That would be like making a toy which is a car with a doll strapped on it's back and forbidding all other toys -- we'll achieve equality, but won't it be artificial? Will boys and girls actually be happier with their toys?

I'm not claiming all unbalance in STEM comes from preference, I'm claiming some may come, and it's important to recognize that to effectively address the situation.
I think GMO is OK as long as you are taking a gene that the plant already has and propagating it over other traits that are less desirable, like breeding birds with blue feathers instead of green feathers because you like blue... thats fine, but when you mix genes from a bird a pig a cow a bacteria and some corn to make corn that flies onto your plate cooks itself and repels insects. . . . that shit IMO is stupid.
https://panopticlick.eff.org

"Your browser fingerprint appears to be unique among the 5,053,325 tested so far."
Trojita 0.5 Qt Imap client is released
The JVM is an insane thing, and with clever enough programmers a lot can be done on top of that.

Were those Java servers written in standard Java, though? Because it's possible to write pretty low-level code in java if you're willing to compromise on standards compliance. Non-GC'ed, direct memory access is possible, I think.
What would you want OO for? First-class functions + HM + typeclasses work fine.
I disagree with your last point, to some extent.

While not strictly necessary, learning a bit of category theory makes FP abstractions such as functors and monoids a bit more accessible.

I can't disagree with the fact that learning category for that sole purpose sounds like a lot of work for too little benefit, though.
Suppose I have a tag on both porno.com and kittens.com. I can fingerprint you across both sites, even if porno.com is incognito. Then you can tweet on kittens.com and I can now tie your kittens.com usage to your twitter usage.

I only need you to engage in one of many non-obviously trackable social interactions ("YES send me a cute kitten every day to my email!") on kittens.com to identify you.
HN is a bunch of linear thinking one-dimensional cyborg community
You can tell an american when oil crisis implies scooters not public transport.
Luckily this debate is about facts, not about your opinion.
Bt plants (like Bt corn) are specifically engineered to not require pesticides. So to start, your 99% is wildly inaccurate. Also, a lot of promising GMO projects focus around enriching vitamin content (golden rice) or making plants more drought-resistant.

And about roundup-ready crops:

"The EPA considered a "worst case" dietary risk model of an individual eating a lifetime of food derived entirely from glyphosate-sprayed fields with residues at their maximum levels. This model indicated that no adverse health effects would be expected under such conditions."

"Early epidemiological studies have not found associations between long-term low-level exposure to glyphosate and any disease."

(off of the wikipedia article: http://en.wikipedia.org/wiki/Glyphosate#Human)
This makes me wonder what the smallest asm.js program could be.
The question is who "you" is here – if the program is being secured against the user, and you are the user, then you don't have freedom 1 of the free software definition: "the freedom to study how the program works, and change it so it does your computing as you wish".

To paraphrase agent Smith, what good is the source code if you're unable to run it?
Then you live in a bubble. Go to T-Centralen. I used to see an older _Swedish_ lady every single Friday night on the green line between T-Centralen and Medis. She wears red, has 'rullator'.

http://www.etc.se/inrikes/utforsakrade-johan-maste-tigga-iho...

Johan isn't alone. Go by the Göta Lejon theatre entrance, you will see Swedish homeless sleeping there. There of course also EU-Migrants nearby in the subway, but you can make out the difference I am sure.

Swedes sleep in their bubbles, thinking everything will be awesome while the government is going bat-shit crazy with (islamic) blasphemy laws, insane migration and allowing Jihadis into the government. Good luck with the pension and and credit-bubble.

Just read that Sweden gave asylum and permanent residency to an ISIS-rapist who tortured a man on camera. They even had a confession.
why should it be dependent upon techies to stop those events, they are not getting funding to do that. The NSA, FBI, CIA, GCHQ et al are being funded expressly for that purpose and are failing to achieve those aims. what they are doing is hoovering up every piece of electronic data they can regardless of whether there is a need or use for it.

I think that actually " all the embarrassingly smart technologists around here" need to spend their time designing and creating better tech that doesnt allow the alphabet soup agencies the option to spy on people in such a broad fahsion, making it expensive and difficult to spy on everyone means they have to spend more time looking for the people worth spying on and only spying when they think it is worthwhile and going to lead to something.

what happens now is they spy on everyone, then after an incident go backwards through the data to see what led up to the incident. Which is useless to all the dead and inujured and usually only works to point out where these agencies missed opportunities to prevent the attack.

To give you an example, the recent terrorist hostage taking in Sydney, there was no warning or raising of the terror threat prior to the incident by the Australian Secret Services, although they are fully involved in the spying and are linked with the NSA and GCHQ. After the event we find out that there were double digit warnings provided by members of the public to a information line put in place to act as a confidential way to raise a concern. If they didnt rely on spying on everyone they would be in a better position to investigate tips such as this and focus all (or more) of their resources on these individuals instead of spreading it thinly across everyone.
I agree.

It's also a typical trait of conspiracy theories (in the negative sense) that they pretend to have figured out more than they possibly could have.

I mean they don't just sell you suspicions (that might even be reasonable), but overdetailed debunkings which are clearly fabricated.

As if they believed that the winner is whoever provides more details, wherever these would come from.
The salaries are probably pretty accurate for people that need to look at job boards to figure out whether they'd be best moving to a new company or city though. If you're in the relatively small subset of software engineers eligible for roles paying north of $200k, the opportunities to radically improve your disposable income and lifestyle are searching for you.
I'm having trouble thinking of something more Canadian than skating to work.
> conjunction fallacy [...] you pick ii, even though we know it's less likely

We know that "mental illness and odd beliefs" is less likely than "odd beliefs". That doesn't mean we know that "mental illness and odd beliefs" is less likely than "no mental illness and odd beliefs", which is the relevant comparison here.

(But, for what it's worth, I think most people who embrace conspiracy theories don't do so as a result of anything that would be diagnosed as a mental illness.)
Is It Possible to Get Instant Auto Loans for Bad Credit?
Wow that was a nice surprise! And a funny but fantastic journey from being unaware of su to being the author of an important implementation of the same.

As for sudo being preferred on Macs, it's the same in Ubuntu world. In fact the default Ubuntu install doesn't even create a password for the root account, as a result I tend to use sudo on Ubuntu and derivates and su on RHEL based distros. Also as far as I know, sudo these days can do everything that su can.
Thanks for your input. Valuable points. And we are in fact, launching a B2C product :)
>Although it costs £10k to run, because that's the type of democracy we have here in the UK apparently.

This is a good thing, despite how it seems on the surface.

If it were free you'd probably have 10,000 candidates. If it were £50, you'd probably have 500. Nobody benefits. The city has to spend lots of money and resources handling large volumes of useless candidates and voters do have any idea of who to pay attention to besides one or two huge names and a mass of idiots.

If you can't get 1000 people to give you £10, you don't have any business running anyway.

A large entry fee does a great job weeding out wonks, crazies, and jokers. Real candidates will spend a lot more than 10k through the process anyway.

In the US I voted during the last election to increase the filing fee from $20 to $500 for mayor of Minneapolis. Obviously a much smaller city but the idea is the same.
Well here is a counter-point: don't ignore the marketing / coolness factor of new technology. It may not be entirely rational from a risk/cost perspective, but given that software engineers are interested in new technology, you could get a sale. Also there is value for marketing your product if it's based on new technology.

(Otherwise I generally agree with slides: software and features are much more important than performance).

One thing which is rational and helps FPGAs is time to market (vs. a giant SoC with long verification time). If you can get your design to market sooner than anyone else you get to charge a premium which could pay for the extra per-chip cost of FPGAs vs. ASICs.
And I always thought sort functions are always tested with millions of randomly generated sequences and the results are compared with the results of other implementations known to be good.
And thank god for the mining of the tar sands, am I right?
Local search and the hill climbing algorithm
Audible Enhanced – .AAX – DRM Removal and Conversion
Apologies; this is a copy-paste from another post from another forum back from 2012, but it is basically the exact same point I am stuck in 2015. Any help?

Here comes the copy-paste: http://stream-recorder.com/forum/audible-enhanced-aax-drm-removal-and-conversion-t13486.html

"I'm trying to remove copy protection from, and convert, audible enhanced files.

Audible's new "Enhanced" format uses .aax files, which as far as I can tell are a variant of .AAC files.

On a mac (which I'm using) they play natively in iTunes - after requiring you to log in to your audible account within iTunes. Requiem doesn't seem to recognize them as DRM protected content, and I can't find any other applications that will even recognize them, much less remove the DRM.

Is there a way to remove DRM, and convert them to unprotected .AAC files? Preferably losslessly."