wbhart

63 ms·

541.
by wbhart 15y ago
Wasn't topiary supposedly the guy who was doing the interview during which the WBC got hacked? If so, they have his voice on tape. Certainly wasn't British. At the time I thought French, but Swedish would fit. The slightly annoying thing is
542.
by wbhart 15y ago
Just for fun I threw up a project I've been working on: https://github.com/wbhart/Cesium In backend.c (esp. lines 171 and following) you can find the beginnings of an LLVM backend (it does work, but doesn't do a whole lot atm). The whole
543.
by wbhart 15y ago
No worries. One problem with adding a Jit is you usually want to put extra information in the ast, such as LLVM objects, so I'm not sure how totally easy it would be to hack in in an unobtrusive way. The other problem is that VMs like LLVM
544.
by wbhart 15y ago
Looks like it could be fun. How attached are you to writing a slow old C virtual machine back end? Why not use a fast JIT/AOT, like the LLVM backend? I could be tempted to just implement one. By the way is there a typo on line 46 of ast.h?
545.
by wbhart 15y ago
Do you mean AOT compilation? From an earlier post I gleaned that the Uladen Swallow project used the LLVM backend, which is variously described as a Jit, Ahead of Time compiler, incremental compiler and various other things. It's clear ther
546.
by wbhart 15y ago
I think I understand now. The PyPy implementation of Python is written using the RPython -> Jit interpreter framework that the PyPy project has. Clever. Am I right in thinking that the drawback of this method is very long compile times
547.
by wbhart 15y ago
Generators probably need to be efficiently inlined to be fast? Maybe this depends on the capabilities of the VM. I think they can also be implemented with continuations which few languages implement due to being a headscrew. I'm just guessi
548.
by wbhart 15y ago
" http://geetduggal.wordpress.com/2010/11/25/speed-up-your-pyt... . lists an example where PyPy is in fact faster than C++ with STL. Not sure how it would compare to well-optimized C, but remember that JIT warmup time will hurt you for sho
549.
by wbhart 15y ago
Thanks for the concise and extremely helpful answers. I have some followups: * What is the Jit itself written in? * You mention that for numeric code PyPy hovers around gcc -O1. What are the other classes of code that you see PyPy as having
550.
by wbhart 15y ago
I have some questions: * Is the Jit in PyPy standalone, i.e. can it be used by other projects independently of Python? Is it documented? * How does PyPy compare with highly optimised C? * Assuming that the benchmarks that used to be at the
551.
by wbhart 15y ago
If I put a % anywhere in the string (except at the end where I think it is ignored) it doesn't give me my robot, but a broken link!
552.
by wbhart 15y ago
This is really excellent. I've always wanted to learn prolog and surprisingly not been able to find a good way. This resource is clear to the point of being boring, which is precisely what I needed. {Add statement about how in the good ole
553.
by wbhart 15y ago
I have not been able to work out two things here: 1) If I define a lambda inside a function, I cannot return the lambda from the function and use it right? 2) Recursive lambdas are not possible on account of the lack of recursion in C macro
554.
by wbhart 15y ago
I would agree that people like miracles and notice them. However miracles are by their very nature the exception, not the norm. Science works by quantifying what is the norm through carefully controlled studies. The reason that alternative
555.
by wbhart 15y ago
This catalyzer shows up regularly on conspiracy theory websites and alternative energy forums. Note that Rossi claims that it is a low energy nuclear reaction and Foccardi claims that the nickel is converted to copper in the reaction. For "
556.
by wbhart 15y ago
It's amazing that members of our species can turn a photograph of earth from a great distance into an emotional appeal to support the belief system of the speaker (Carl believed that the laws of science were an impersonal God). Personally I
557.
by wbhart 15y ago
The competition is apparently suspended. I don't understand how part of the solution could "become public" unless someone at his company leaked the info. I guess you combine the four numbers Mu = 231, Phi = 158, Delta = 553, Beta = 68 to ge
558.
by wbhart 15y ago
You didn't need 3 guesses. The sum of each partition has to be a factor of the number. In particular the sum of the first partition has to be a factor. Then the second. That already gives you the answer I think.
559.
by wbhart 15y ago
Thanks, though I already have a small language working with the LLVM Jit that accepts the language described by this grammar: http://selmer.warwick.ac.uk/c.grm I'm in the process of rewriting it to use peg though, as I was using a parser
560.
by wbhart 15y ago
You can just type the IP address into your browser. But that is unlikely to be it. If the puzzle maker has even half a brain, those four numbers are only some part of the puzzle. If you look at the equations, they are way more complex than
561.
by wbhart 15y ago
Well, none of the 24 combinations of those seems to give a valid IP address. Probably they screwed up. Of course a standard IP address wouldn't have values above 255 anyhow.
562.
by wbhart 15y ago
Unless I am mistaken, I think the title could do with being changed. It looks to me like the Jit compiler is written in C++. LLVM is not written in Ruby. What is implemented in Ruby here is a version of the toy Kaleidoscope language which i
563.
by wbhart 15y ago
There's an article somewhere about how the HN algorithm works. I think it ranks articles roughly speaking according to how many upvotes they received over a given time period. So you need sustained and concentrated interest to keep them up
564.
by wbhart 15y ago
I just couldn't get past having different operators for floating point and integer arithmetic. So O'Caml never passed go, for me. Imagine a mathematical system in O'Caml with polynomials, matrices and many other mathematical objects that yo
565.
by wbhart 15y ago
Haskell has some great features, such as type classes (the power of these has not been fully realised). In other cases I have mixed feelings. The monad business is sometimes absolutely brilliant (Parsec is a good example) and at other times
566.
by wbhart 15y ago
No. I did read an article about the GHC LLVM backend and it mentions the Cmm language (a variant of C--). But there was no mention of GC. In fact, this thesis: http://www.cse.unsw.edu.au/~pls/thesis/davidt-thesis.pdf seems to state that C
567.
by wbhart 15y ago
Here is a better example than the "Group action" one, and it's a real clanger. Look at the page on "Group representation". There it defines a notion of "irreducible representation" in the section "Reducibility". Now, notice the phrase "A su
568.
by wbhart 15y ago
Agreed. Both sides would need to learn a lot for that to happen. I think there's a vast chasm in fact. Moreover, most academics don't have time for the wiki part. They barely have time for the papers part. Some academics get to write gradua
569.
by wbhart 15y ago
LLVM has almost no support for GC and it is about the biggest problem that just hits you in the face when you use it. What I've been doing for my own experiments is very naive (and quite possibly broken). I've been implementing an interpret
570.
by wbhart 15y ago
Yes, it is. And I suspect the Scala people aren't advocating that it move away from the JVM. However, I can definitely say, should a Scala on LLVM become available with trivial FFI with native code and close to compiled C performance even

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