Here are all the entries in http://reproducibility.cs.arizona.edu/ where I've mentioned problems in various Facebook/G+ threads.
A number of other errors are catalogued by Peter Bailis here: https://gist.github.com/pbailis/9629050
Note: I'm a coauthor on this one.
Digital cryptography! This is a subject I've been interested in since taking a class with Prof. Fred Schneider back in college. Articles pop up on Hacker News fairly often that pique my interest and this technique is the result of one of them.
Specifically, this is about Lamport signatures. There are many signature algorithms (ECDSA and RSA are the most commonly used) but Lamport signatures are unique because they are formed using a hash function. Many cryptographers believe that this makes them resistant to attacks made possible by quantum computers.
| import Control.Monad | |
| data LSymbol = LRule Char | LDeriv String | |
| type Alphabet = [LSymbol] | |
| type Axiom = [LSymbol] | |
| -- a production is a finite mapping of LSymbol -> LSymbol | |
| -- if no production exists for a given LSymbol on the LHS of a Production |
| import Control.Monad | |
| import Data.Ratio | |
| data FakeRatio = FakeRatio { numr :: Int, denom :: Int} deriving (Show) | |
| data SBTriple = SBTriple { left :: FakeRatio, | |
| mid :: FakeRatio, | |
| right :: FakeRatio} | |
| data Directions = TLeft | TRight deriving (Show) |
| struct A {n: uint} | |
| impl A: cmp::Eq { | |
| pure fn eq(other: &A) -> bool { | |
| self.n == other.n | |
| } | |
| pure fn ne(other: &A) -> bool { | |
| !self.eq(other) | |
| } | |
| } |
| PayPal blocks copy/paste actions in their "change password" form, | |
| citing some irrelevant security issues as the reason. That's a | |
| load of crap, and they know it -- disabling copy/paste makes it a | |
| lot harder to use a decent password generator and a lot easier to | |
| screw up your pwd when retyping, especially if it's a long one | |
| (as it should be!). | |
| So, here's the quick'n'dirty way to use an externally generated | |
| password in your PayPal account: |
| #include <SDL2/SDL.h> | |
| #define MUS_PATH "Roland-GR-1-Trumpet-C5.wav" | |
| // prototype for our audio callback | |
| // see the implementation for more information | |
| void my_audio_callback(void *userdata, Uint8 *stream, int len); | |
| // variable declarations | |
| static Uint8 *audio_pos; // global pointer to the audio buffer to be played |
Delimited continuations manipulate the control flow of programs. Similar to control structures like conditionals or loops they allow to deviate from a sequential flow of control.
We use exception handling as another example for control flow manipulation and later show how to implement it using delimited continuations. Finally, we show that nondeterminism can also be expressed using delimited continuations.
