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Hidden features of Scala
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trait Functor[F[_]] {
def fmap[A, B](f: A => B, fa: F[A]): F[B]
}
Now, if you have a Functor[List], you can map over lists. If you have a Functor[Tree], you can map over trees. But more importantly, if you have Functor[A] for any A of kind (*->*), you can map a function over A.
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What are the Dangers of Method Swizzling in Objective-C?
... calls that, but the _cmd argument isn't setFrame: like it should be. It's now my_setFrame:. The original implementation is being called with an argument it never expected it would receive. This is no good.
There's a simple solution — use the alternative swizzling technique defined above. The arg...
Get absolute path of initially run script
I have searched high and low and get a lot of different solutions and variables containing info to get the absolute path. But they seem to work under some conditions and not under others. Is there one silver bullet way to get the absolute path of the executed script in PHP? For me, the script wil...
Why do people say that Ruby is slow? [closed]
...e signal processing app. It's easier to see what people are talking about now after all these helpful answers.
– stephenmurdoch
Apr 27 '10 at 3:13
1
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RuntimeError on windows trying python multiprocessing
...will import (i.e. execute) the main module at start. You need to insert an if __name__ == '__main__': guard in the main module to avoid creating subprocesses recursively.
Modified testMain.py:
import parallelTestModule
if __name__ == '__main__':
extractor = parallelTestModule.ParallelExt...
python: How do I know what type of exception occurred?
...y, it's so that you don't hide:
the fact that an error occurred
the specifics of the error that occurred (error hiding antipattern)
So as long as you take care to do none of those things, it's OK to catch the generic exception. For instance, you could provide information about the exception to ...
Show all Elasticsearch aggregation results/buckets and not just 10
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Note that setting size:0 is now deprecated, due to memory issues inflicted on your cluster with high-cardinality field values. github.com/elastic/elasticsearch/issues/18838. Instead, use a real, reasonable number between 1 to 2147483647.
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Define a lambda expression that raises an Exception
...ef raise_(ex):
raise ex
y = lambda: raise_(Exception('foobar'))
But if your goal is to avoid a def, this obviously doesn't cut it. It does, however allow you to conditionally raise exceptions, e.g.:
y = lambda x: 2*x if x < 10 else raise_(Exception('foobar'))
Alternatively you can rai...
What is the purpose of python's inner classes?
...es confuse me. Is there something that can't be accomplished without them? If so, what is that thing?
9 Answers
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Difference between len() and .__len__()?
Is there any difference between calling len([1,2,3]) or [1,2,3].__len__() ?
4 Answers
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