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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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Where is the C auto keyword used?
... about the auto keyword and in the course of time I actually forgot what it is. It is defined as:
9 Answers
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Should I pass a shared_ptr by reference? [duplicate]
...general, you should pass the shared pointer as a straight copy. This gives it its intended semantics: Every scope that contains a copy of the shared pointer keeps the object alive by virtue of its "share" in the ownership.
The only reason not to always pass by value is that copying a shared pointer...
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 ...
Collection versus List what should you use on your interfaces?
...s to why not List<T>, The reasons are future-proofing and API simplicity.
Future-proofing
List<T> is not designed to be easily extensible by subclassing it; it is designed to be fast for internal implementations. You'll notice the methods on it are not virtual and so cannot be overridd...
Setting the correct encoding when piping stdout in Python
...thon program, the Python interpreter gets confused about encoding and sets it to None. This means a program like this:
10 A...
Generating PDF files with JavaScript
... into PDF files from a web page and I was hoping I could do this entirely within JavaScript. I need to be able to draw text, images and simple shapes. I would love to be able to do this entirely in the browser.
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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...
Pairs from single list
...pairs. I was wondering which would be the pythonic and efficient way to do it, and found this on Google:
9 Answers
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How to place and center text in an SVG rectangle
...y solution to center text horizontally and vertically in SVG:
Set the position of the text to the absolute center of the element in which you want to center it:
If it's the parent, you could just do x="50%" y ="50%".
If it's another element, x would be the x of that element + half its width (and...