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Where does the “flatmap that s***” idiomatic expression in Scala come from?
...t you can replace a lot of tedious if/then/else code you would write with calls to flatMap (and other higher order functions).
This is especially true for Options (see http://tonymorris.github.io/blog/posts/scalaoption-cheat-sheet/)
But it applies to other monads as well (although I have to admit...
How to prevent multiple instances of an Activity when it is launched with different Intents
...unched using the "Open" button on the Google Play Store app (previously called Android Market). It seems that launching it from the Play Store uses a different Intent than launching it from the phone's application menu of icons. This is leading to multiple copies of the same Activity being launc...
What does T&& (double ampersand) mean in C++11?
...e in the draft C++11 standard, but are not true for the final one! Specifically, it says at various points that rvalue references can bind to lvalues, which was once true, but was changed.(e.g. int x; int &&rrx = x; no longer compiles in GCC) – drewbarbs Jul 13 '14 at 16:12
The biggest d...
Empty arrays seem to equal true and false at the same time
...
You're testing different things here.
if (arr) called on object (Array is instance of Object in JS) will check if the object is present, and returns true/false.
When you call if (arr == false) you compare values of this object and the primitive false value. Internally, a...
How do I verify a method was called exactly once with Moq?
How do I verify a method was called exactly once with Moq? The Verify() vs. Verifable() thing is really confusing.
3 A...
Difference between 'python setup.py install' and 'pip install'
I have an external package I want to install into my python virtualenv from a tar file.
What is the best way to install the package?
...
Appending an element to the end of a list in Scala
...'s because you shouldn't do it (at least with an immutable list).
If you really really need to append an element to the end of a data structure and this data structure really really needs to be a list and this list really really has to be immutable then do eiher this:
(4 :: List(1,2,3).reverse).rev...
What is the use for Task.FromResult in C#
In C# and TPL ( Task Parallel Library ), the Task class represents an ongoing work that produces a value of type T.
6 Ans...
Why is char[] preferred over String for passwords?
... believe this is implementation-specific - the garbage collector may clear all memory as it goes, to avoid this sort of thing. Even if it does, there's still the time during which the char[] contains the actual characters as an attack window.
...
Why does `a == b or c or d` always evaluate to True?
...r is more literal minded.
if name == "Kevin" or "Jon" or "Inbar":
is logically equivalent to:
if (name == "Kevin") or ("Jon") or ("Inbar"):
Which, for user Bob, is equivalent to:
if (False) or ("Jon") or ("Inbar"):
The or operator chooses the first argument with a positive truth value:
if ("Jon")...