ryani
Joined 12 years ago
Karma
101
Submissions
49
Member since
May 21
Recent submissions
Comment · 3 months ago
Listening to Mike Duncan's "Revolutions" podcast I was distinctly struck with the idea that the main thing leftists like to do, even more than fighting rightists, is fighting other leftists.
Comment · 3 months ago
Sadly, you can't easily do the full pimpl idiom in C++.
The pimpl idiom is a C idiom where a header declares an opaque structure and prototypes of functions that take pointers to that structure. In C the OP example would look something like
// widget.h
typedef struct Widget_t Widget; /* opaque! */
Widget* Widget_Create(const string* pName);
Widget* Widget_Clone(Widget*);
void Widget_Destroy(Widget*);
void Widget_click(Widget*);
int Widget_clickCount(const Widget*);
const string* Widget_label(const Widget*);
// widget.c
struct Widget_t {
int clicks;
string *name;
};
// ... implementations of the functions from the .h ...
But in c++ we like to use methods on objects, and in order to do this, you need the class declaration in scope, which means your current compilation unit needs to have seen all of Widget's data members. In practice this means if you try to use "pimpl" in C++, you do something like the OP where there is a pointer to an opaque type inside your class.
However, this is not the same thing. Methods are called with a `this` pointer, which means every access to the internal structure adds a second pointer dereference. This is why this isn't the true pimpl -- it wastes an extra deref on every access.
You can get true pimpl in current C++ but it's a lot of boilerplate and heavily relies on compiler inlining. An implementation of the example from the OP: https://godbolt.org/z/6EznxeG1n . In practice this is too much work, hard to read, and so nobody does it.
For the c++ standards committee: please add an "opaque class" feature where the class can only define non-virtual method prototypes. Then the full class declaration, in the associated cpp file, could include its parent classes, actual data layout, and function implementations.
Comment · 4 months ago
> I can tell you right now that you would have to pay me far above market rate to get me to move
If everyone feels that way, then it's not an above-market rate, it's by definition the market rate. The market rate for a job might be different at different locations.
(Note that I'm not taking a position on whether or not using the H1B program to reduce the market rate here is a good idea)
Comment · 9 months ago
What statutory penalty?
https://www.copyright.gov/512/
Read the requirements for a takedown notice. The only thing a DMCA notice needs to claim under penalty of perjury is that you are authorized to enforce the copyright that you are claiming. The report from the copyright office on the linked page states:
> Senders of both takedown notices and counter-notices are liable for damages if they make knowing material misrepresentations regarding whether the material to be taken down is infringing, or has been removed or disabled by mistake or misidentification. Courts have appropriately interpreted this provision by requiring actual knowledge or willful blindness of falsity, not merely negligent or unreasonable misrepresentation.
"Knowing" does a lot of heavy lifting here. Courts have determined that someone who uses an automated system to identify infringing content and submits takedown notices against all of that content does not "knowingly" misrepresent anything.
Furthermore, even in the case where there is bad faith, there's no statutory penalty, it relies on the targeted party suing and in court proving BOTH bad faith, and damages.
The DMCA has no teeth against false claims.
Comment · 1 year ago
I want to be able to click-and-drag. For example, in this row
1 2 |x x |
Similarly in the inverted case, if I have marked cells and right-click-and-drag next to them it should mark the empty spots I cross over with Xs.
Important: this doesn't change the state of any cell that wasn't blank to start out. You should have to click on a marked cell to clear it (or right click to replace it with an X). And similarly to above, if you drag, it should change only the cells you touch that match the starting state of your original cell to the new state.
Comment · 1 year ago
This is also available (with an included Flash emulator, so playable on modern machines) in Zach's free retrospective "Zach-like" [1]
Comment · 1 year ago
How is "Baumol effect" different from supply and demand for any limited resource?
Let's say that some new use for copper is discovered, that drastically increases the demand for copper. The cost of existing items that use copper is going to go up, even if those items are no more productive than they used to be, because the new items are now in high demand.
You can see this effect in real life with GPUs; it's much more expensive to buy a gaming graphics card today than it was a decade ago, because GPUs are in high demand for other applications.
So, increasing the productivity of labor in some sector is going to do the same thing supply and demand does to anything else -- the cost of labor goes up, but not as much as the productivity in that sector, and the producers of labor will enjoy higher demand.
Comment · 2 years ago
Hi Chaim! I really enjoyed working with you on Spore. What have you been up to in the intervening years besides writing this book?
Comment · 2 years ago
I think something like Unity or Gamemaker or even Scratch fills that niche now. They are a bit more game-focused than Hypercard (which was really more of an early iteration on the web), but, I think, capture a similar feeling of empowerment and creativity among nerdy young people as Hypercard did for nerdy young me.
Comment · 3 years ago
This is such a crazy take. "Because the waste is so huge, it's impossible to do anything".
It's not like any individual reform is going to suddenly end all that waste and put everyone involved out of a job. Iterative small improvements make a real difference in people's lives, and won't provoke an immediate giant supply-side shock.
I don't pretend to have the answers to the question of "what reforms should we do?" but throwing our hands up and saying "nothing!" is not the answer.
Comment · 3 years ago
Here's the standard algorithm for this problem
function weightedRandom(weight, outcomes){
var total = sum( weight );
var roll = Math.random()*total; // value in the range [0,total)
var seen = 0;
for(let i=0; i<weight.length; i++) {
seen += weight[i];
if(roll<seen)
return outcomes[i];
}
}Comment · 4 years ago
I think there's a difference between "blockchain + PoW" and "blockchain". Blockchain taken literally is just verification of history via hashing. It's a form of provenance that is hard to fake. Even if you are a central authority as to what transactions are being made, you can't rewrite history beyond any point that you've made publicly visible, without losing the trust of people who rely on you as a central authority, as to do so you would need to break the hashing algorithm.
Comment · 5 years ago
> The adage that teachers still teach, "don't cite Wikipedia" -- [...] what are people supposed to use?
Wikipedia cites sources. Go to those sources, find the ones that best line up with the data you need, and cite them directly.
Treat Wikipedia like an aggregator -- you wouldn't cite an HN post, you'd cite the link it pointed at.
Comment · 5 years ago
If you raise your prices, you drive away legitimate customers but don't drive away fraudsters, since the fraudsters aren't actually paying with real money. So raising your price increases the percentage of fraud you see, which means you probably need to raise your prices further, which further increases the relative amount of fraud.
To counteract this negative feedback loop, assuming the increased prices don't drive away all of your real customers, you can spend the increase on transaction analysis, and turn away customers based on their likelihood of fraud, so you've added inefficiency into the system to help deal with a criminal element, and also likely turned away real sales due to false positives in your analysis.
It's no surprise that these types of merchants are looking for a disruptive technology to remove this inefficiency. Doing so would allow them to charge less and outcompete as well as capture the entire market of people marked as false positives by other merchants.