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How to map and remove nil values in Ruby
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Ruby 2.7 is introducing filter_map for this exact purpose. It's idiomatic and performant, and I'd expect it to become the norm very soon.
For example:
numbers = [1, 2, 5, 8, 10, 13]
enum.filter_map { |i| i * 2 if i.even? }
# => [4, 16, 20]
In your case, as the block evaluates to falsey, simp...
Android Fragments: When to use hide/show or add/remove/replace?
...longer visible. So you could technically still interact with the fragment and reattach its UI later you need to. If you replace the fragment, the you are actually pulling it out of the container and it will go through all of the teardown events in the lifecycle (onPause, onStop, etc) and if for so...
Generate random number between two numbers in JavaScript
Is there a way to generate a random number in a specified range (e.g. from 1 to 6: 1, 2, 3, 4, 5, or 6) in JavaScript?
23 A...
Why doesn't C have unsigned floats?
...If C++ did support it, then you would be sometimes using an unsigned float and not realizing that your performance has just been killed. If C++ supported it then every floating point operation would need to be checked to see if it is signed or not. And for programs that do millions of floating poi...
How to export revision history from mercurial or git to cvs?
...a project that uses cvs. We want to use a distributed vcs to make our work and when we finish or maybe every once in a while we want to commit our code and all of our revision history to cvs. We don't have write access to the project's cvs repo so we can't commit very frequently. What tool can we us...
How to Reverse Fragment Animations on BackStack?
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According to the android documentation for custom animation:
Change:
ft.setCustomAnimations(R.anim.slide_in, R.anim.hyperspace_out);
To:
ft.setCustomAnimations(R.anim.slide_in, R.anim.hyperspace_out, R.anim.hyperspace_in, R.anim.slide_ou...
How can I see what has changed in a file before committing to git?
...ere are three useful ways to use git diff:
Show differences between index and working tree; that is, changes you haven't staged to commit:
git diff [filename]
Show differences between current commit and index; that is, what you're about to commit (--staged does exactly the same thing, use what y...
Wrapping a C library in Python: C, Cython or ctypes?
...Python application. I don't want to wrap the whole API, only the functions and datatypes that are relevant to my case. As I see it, I have three choices:
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Check if object is file-like in Python
...ts are 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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What is the fastest or most elegant way to compute a set difference using Javascript arrays?
Let A and B be two sets. I'm looking for really fast or elegant ways to compute the set difference ( A - B or A \B , depending on your preference) between them. The two sets are stored and manipulated as Javascript arrays, as the title says.
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