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Why is there “data” and “newtype” in Haskell? [duplicate]
It seems that a newtype definition is just a data definition that obeys some restrictions (e.g., only one constructor), and that due to these restrictions the runtime system can handle newtype s more efficiently. And the handling of pattern matching for undefined values is slightly different.
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Getting a map() to return a list in Python 3.x
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Do this:
list(map(chr,[66,53,0,94]))
In Python 3+, many processes that iterate over iterables return iterators themselves. In most cases, this ends up saving memory, and should make things go faster.
If all you're going to do is iterate over this list eventually, there's no need to even con...
What is the difference between exit and return? [duplicate]
What is difference between return and exit statement in C programming when called from anywhere in a C program?
4 Answers
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jQuery - Get Width of Element when Not Visible (Display: None)
It seems like in jQuery when an element is not visible width() returns 0. Makes sense, but I need to get the width of a table in order to set the width of the parent before I show the parent.
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Why is “throws Exception” necessary when calling a function?
...o specify a throws clause for all classes. Specifically, classes that are either an Error or RuntimeException or any of the subclasses of these two. In your case Exception is not a subclass of an Error or RuntimeException. So, it is a checked exception and must be specified in the throws clause, if ...
Is there any overhead to declaring a variable within a loop? (C++)
...laring a variable inside a loop and I was wondering what's wrong until he cited performance as the reason not to do so and I was like "WTF!?".
– Mehrdad Afshari
Jun 11 '09 at 19:35
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Check if object is file-like in Python
...objects in Python that behave like a real file, e.g. have a read() and a write method(), but have a different implementation. It is and realization of the Duck Typing concept.
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Is it possible to make the -init method private in Objective-C?
I need to hide (make private) the -init method of my class in Objective-C.
9 Answers
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Why does C++11's lambda require “mutable” keyword for capture-by-value, by default?
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It requires mutable because by default, a function object should produce the same result every time it's called. This is the difference between an object orientated function and a function using a global variable, effectively...
Programmatically get own phone number in iOS
...K Agreement as of Nov 5, 2009. Our application was just rejected for using it. Here's the response from Apple:
"For security reasons, iPhone OS restricts an application (including its preferences and data) to a unique location in the file system. This restriction is part of the security feature kno...