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Easy idiomatic way to define Ordering for a simple case class
I have a list of simple scala case class instances and I want to print them in predictable, lexicographical order using list.sorted , but receive "No implicit Ordering defined for ...".
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How can I select rows with most recent timestamp for each key value?
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This can de done in a relatively elegant way using SELECT DISTINCT, as follows:
SELECT DISTINCT ON (sensorID)
sensorID, timestamp, sensorField1, sensorField2
FROM sensorTable
ORDER BY sensorID, timestamp DESC;
The above works ...
Can two different strings generate the same MD5 hash code?
...his is used to check whether a certain binary asset is already in our application. But is it possible that two different binary assets generate the same MD5 hash. So is it possible that two different strings generate the same MD5 hash?
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warning about too many open figures
...thing out of scope. Your right that close won't work on the figure object, call it like plt.close(), instead of fig.clf().
– Hooked
Feb 19 '14 at 15:12
5
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Why should I declare a virtual destructor for an abstract class in C++?
.... When they come to delete it, if the destructor is non-virtual, they will call the interface's destructor (or the compiler-provided default, if you didn't specify one), not the derived class's destructor. Instant memory leak.
For example
class Interface
{
virtual void doSomething() = 0;
};
cl...
How to debug stream().map(…) with lambda expressions?
...collect(Collectors.toList());
UPDATE:
I think you're getting confused because map is an intermediate operation - in other words: it is a lazy operation which will be executed only after a terminal operation was executed. So when you call stream.map(n -> n * 2) the lambda body isn't being execu...
npm - how to show the latest version of a package
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You can use:
npm show {pkg} version
(so npm show express version will return now 3.0.0rc3).
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Trigger change event of dropdown
....trigger('change');
});
You must declare the change event handler before calling trigger() or change() otherwise it won't be fired. Thanks for the mention @LenielMacaferi.
More information here.
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Can I create a One-Time-Use Function in a Script or Stored Procedure?
In SQL Server 2005, is there a concept of a one-time-use, or local function declared inside of a SQL script or Stored Procedure? I'd like to abstract away some complexity in a script I'm writing, but it would require being able to declare a function.
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Fixing slow initial load for IIS
...eature for low traffic websites where it recycles unused worker processes, causing the first user to the site after some time to get an extremely long delay (30+ seconds).
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