Although I don’t bear any animosity against most dutch loanwords (except those Anglo-Saxon), the dictionary of the dutch Bond tegen Leenwoorden is a true joy to read.
Since yesterday I, for the first time, enjoy the anything-but-special age of 21 years.
Windows 7 Sins. I strongly agree with points 1, 3, 4, 5 and 6. The arguments for points 2 and 7 are a bit weak, but I do agree with the conclusions.
For the non US audience, it would have been nice to note that if Microsoft (or the US) would recall all foreign licenses for Windows, our entire government is crippled.
were both victim of a DDoS today. Silently, I always hoped that a really long-lasting one will convince them to put effort in a distributed scheme.
Maybe I should be waiting for another Wave.
When I wanted to react to any changes to a
input textbox immediately, my first instrinct was to use
onChange, however, is called when the
input loses focus.
onKeyPress then? Isn’t called on backspaces.
onKeyDown, maybe? It does get called, but the effect of the keystroke isn’t yet applied, for the return value determines whether it that is done in the first place. (Same story for
onKeyPress by the way.)
onKeyUp does work a bit, except if someone is holding down a single key, for a while.
The solution: hook
onKeyUp and use
setTimeout with a timeout of 0. Yugh. I hate DOM.
: I actually tested this only on one browser.
When I want to generate usernames from real names, which can contain non-ascii characters, you can’t simply ignore the unicode characters. For instance, email@example.com is the right e-mail address for DaniŽlle, firstname.lastname@example.org isn’t.
There’s trick. Unicode has got a single code for Ž itself, but it has also got a code which (simplified) adds ® on top of the previous character. The unicode standard defines a normal form in which (at least) all such characters, which can be, are represented using such modifiers. If you then simply ignore the non-ascii representable codes, you’ll get the desired result.
unicodedata.normalize('NFKD', txt).encode('ASCII', 'ignore').
However, this isn’t the right solution. For instance, in german, one prefers ue as a replacement of Ł over u.
new Date(2009, 1, 1) represents the first of February 2009. Not the second of February nor the first of January. Why this stupidity?
When decoding, for instance, a variable-bitrate MP3, gstreamer reported durations are, to say the least, estimates. I’ve tried to get a better result in a few ways. First off, some files yield a
duration tag, but even if you’re lucky and it is there, there are no guaranties about precision. After that I tried seeking to the end (
GST_SEEK_END) of the stream and querying the position, which gstreamer didn’t like. Finally, routing the audio into a
fakesink, waiting for the end of stream and then querying for the position gives the right result. It’s not the prettiest method, but it works.
This is a Python script that prints the duration of a media to stdout.
is ugly, but is nice! The solution: prefix
In a few hours Iíll travel the short distance to Bruxelles to visit Fosdem. Once again Iím pretty excited . Lets hope this time the pink elephants of the Delirium Cafe don’t crush me. If you’re also going, drop me a comment.
It’s soon. The 14th of februari, 00:31:30 (Europe/Amsterdam). Will the world end? Will ancient libc code giggle and break?
Assign 1 to True and 0 to False. Now the minimum corresponds to “and” and maximum to “or”. If you give it a bit more though, less or equal to corresponds to implication. This is a lot more general than this specific case. Add .5 for a third value (eg. NULL) and it still yields natural results.
We can recognize the behaviour of minima and maxima in a lot of other things. Take for instance set inclusion as order with intersection as minimum and union as maximum. Actually, the link between general order and set inclusion is frequently made to then propose that “intersection of two set of cases” and “logical and” do look a lot alike.
This is just the tip of the huge iceberg. Order appears everywhere! Everywhere in Math. Everywhere in CS. And its just recognizing simple order I’ve demonstrated. Other useful concepts in order theory that I didn’t even touch are Galois Connections and formal concept analysis.
example of an order are integers with bitwise or and bitwise and. It is left as an exercise to the reader when one integer is greater than another.
Interested? Buy an Introduction to Lattices and Order.
Some singletons eat slightly more resources, than you want to give them for free. For instance, if you have a home-brew threadpool singleton, you don’t want it to create its threads if you are not going to use it. The solution: a simple function that creates a stub which proxies attribute access to an ad-hoc created instance.
A Hashtable algorithm is a specific algorithm to implement key-value pair datastructure with efficient by-key look-ups using hashing of the keys. A hashtable contains a list of buckets. In a simple implementation, the i-th bucket, contains the key-value pairs in a list of which the key has a hash that is i modulo the amount of buckets. The hash-table would increase the amount of buckets if any bucket contains more than a fixed amount of pairs. This results in a constant-time look-up, but an insertion might invoke a expensive rebuild.
There are a few variations on Hash Tables. I’d like to share a really smart one: the Cuckoo Hashtable.
The Cuckoo hashtable expects two different hash-functions for the keys. Instead of storing a list of pairs in each bucket, the Cuckoo Hash table stores a single pair in each bucket. When inserting a pair, it is inserted in one of the two possible locations. If it happens to be occupied, the old pair is replaced. Then the replaced pair is inserted at its other possible location, potentially kicking out another pair. This step is repeated, until there is no displaced pair or a loop is detected. When a loop is detected, the hash-functions can be changed, if the buckets are for the most part empty -or- when the table is almost full, the amount of buckets can be increased. It can be shown that an insertion has a amortized constant time. (The buckets can be resized in-place, and each entry is repositioned as if it was displaced by another.)
…and didn’t want to loose it if my control servers got shut down, I’d let every orphaned zombie randomly connect to hosts in a given IP range, and challenge them to give a preimage of a hardcoded hash. [ detail: add a salt to prevent replay attacks ]. With a sufficiently safe casu quo large range, it also might be helpfull to allow zombies to forward still orphan zombies.
The sound and performance really aren’t that good, but the visual connection is so powerful: