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Why create “Implicitly Unwrapped Optionals”, since that implies you know there's a value?
... var button: UIButton!
var buttonOriginalWidth: CGFloat!
override func awakeFromNib() {
self.buttonOriginalWidth = self.button.frame.size.width
}
}
Here, you cannot calculate the original width of the button until the view loads, but you know that awakeFromNib will be called b...
How do I replace NA values with zeros in an R dataframe?
...ce(., is.na(.), 0))
The Complete Analysis -
Updated for dplyr 0.8.0: functions use purrr format ~ symbols: replacing deprecated funs() arguments.
Approaches tested:
# Base R:
baseR.sbst.rssgn <- function(x) { x[is.na(x)] <- 0; x }
baseR.replace <- function(x) { replace(x, is...
How is Math.Pow() implemented in .NET Framework?
... things up, I decided to take a look at the implementation of Math.Pow() function. But in .NET Reflector , all I found was this:
...
How to integrate nodeJS + Socket.IO and PHP?
...p can broadcast messages to the socket. the socket will inspect the signed token, and if it passes, ti will then broadcast the message. this is good for preventing spam and ensure data integrity. so never post directly to the node socket from the client. instead post to php app with ajax, then relay...
What's to stop malicious code from spoofing the “Origin” header to exploit CORS?
... secure your site. If you are serving protected data, use cookies or OAuth tokens or something other than the Origin header to secure that data. The Access-Control-Allow-Origin header in CORS only dictates which origins should be allowed to make cross-origin requests. Don't rely on it for anything m...
Haskell: Lists, Arrays, Vectors, Sequences
... standard library, and for that matter the prelude, is full of useful list functions that should litter your code (foldr,map,filter). Lists are persistant , aka purely functional, which is very nice. Haskell lists aren't really "lists" because they are coinductive (other languages call these strea...
Templated check for the existence of a class member function?
...to write a template that changes behavior depending on if a certain member function is defined on a class?
29 Answers
...
Pointer expressions: *ptr++, *++ptr and ++*ptr
...hen increments dereferenced value
And here's a fourth, every bit as much fun as the other three:
(*ptr)++ // effectively forces a dereference, then increments dereferenced value
The first and second will crash if ptr is actually an array identifier. The third and fourth will crash if ptr points...
How Drupal works? [closed]
...can be confusing on this front, partially because it has a relatively deep function stack. Although it's procedural PHP it's purely event/listener driven in its architecture, and there's no simple "flow" in the main PHP script for you to look though. I recently did a presentation on this very subjec...
How to trace the path in a Breadth-First Search?
...
I thought I'd try code this up for fun:
graph = {
'1': ['2', '3', '4'],
'2': ['5', '6'],
'5': ['9', '10'],
'4': ['7', '8'],
'7': ['11', '12']
}
def bfs(graph, forefront, end):
# assumes no cycles
next_...