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Why is an int in OCaml only 31 bits?
...you take up almost 20 Byte.
However, the trick is that with so-called immutable value types like integers, you usually don't need all the metadata in the object header: you can just leave all that stuff out, and simply synthesize it (which is VM-nerd-speak for "fake it"), when anyone cares to look....
What is the explanation for these bizarre JavaScript behaviours mentioned in the 'Wat' talk for Code
...vaScript does help to make the confusing outputs clearer. See the coercion table below
+-----------------+-------------------+---------------+
| Primitive Value | String value | Numeric value |
+-----------------+-------------------+---------------+
| null | “null” | ...
List of Big-O for PHP functions
...all: Thanks! I did a bit of reading and it turns out PHP uses 'nested' hashtables for collisions. That is, instead of a logn structure for collisions it simply uses another hashtable. And I do understand that practically speaking PHP hashtables give O(1) performance, or at least O(1) on average - t...
Efficiency of purely functional programming
...out simulating random access memory using only pointers). Pippenger also establishes that there are algorithms for which that is the best you can do; there are problems which are O(n) in the impure system which are Ω(n log n) in the pure system.
There are a few caveats to be made about this paper....
How efficient is locking an unlocked mutex? What is the cost of a mutex?
... system limit. But too many of them spells nightmare for debugging. Simple table:
Less locks means more contentions (slow syscalls, CPU stalls) and lesser parallelism
Less locks means less problems debugging multi-threading problems.
More locks means less contentions and higher parallelism
More lo...
Pointer expressions: *ptr++, *++ptr and ++*ptr
...fix increment expression
1. Precedence. A quick glance at the precedence table for operators will tell you that postfix increment has a higher precedence (16) than dereference / indirection (15). This means that the complex expression *p++ is going to be grouped as: *(p++). That is to say, the * p...
REST API Token-based Authentication
... shared secret, and then use a salt that doesn't change to prevent rainbow table attacks. The username field seems like a good place to put the nonce too, since it is part of the auth. So now you have a clean call like this:
nonce = generate_secure_password(length: 16);
one_time_key = nonce + '-' +...
Grouping functions (tapply, by, aggregate) and the *apply family
...rs of many types together in a traditional rectangular dataset. While data.table and plyr might add a certain type of syntax that some might find more comfortable, they are extending and acting on data.frames respectively.
– thelatemail
Aug 20 '14 at 6:08
...
How to integrate nodeJS + Socket.IO and PHP?
...ript>
var socket = io();
$(document).ready(function($) {
$('.rules-table').on('click', '.runRule', function(event) {
event.preventDefault();
/* Act on the event */
var ruleID = $(this).parents('tr').attr('id');
// send notification before going to post
socket.emit('new_...
What Haskell representation is recommended for 2D, unboxed pixel arrays with millions of pixels?
...a also has a rich interface for doing so. Vector on its own does not.
Notable mentions:
hmatrix, a custom array type with extensive bindings to linear algebra packages. Should be bound to use the vector or repa types.
ix-shapeable, getting more flexible indexing from regular arrays
chalkboard, ...