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What are type lambdas in Scala and what are their benefits?
... point[A](a: A): M[A]
def bind[A, B](m: M[A])(f: A => M[B]): M[B]
}
Now, Either is a type constructor of two arguments, but to implement Monad, you need to give it a type constructor of one argument. The solution to this is to use a type lambda:
class EitherMonad[A] extends Monad[({type λ[...
Selecting only numeric columns from a data frame
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## nums <- sapply(x, is.numeric)
For a more idiomatic modern R I'd now recommend
x[ , purrr::map_lgl(x, is.numeric)]
Less codey, less reflecting R's particular quirks, and more straightforward, and robust to use on database-back-ended tibbles:
dplyr::select_if(x, is.numeric)
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Removing first x characters from string?
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@jamylak does it work, now , if so do you need to downvote?
– U10-Forward
Jan 29 at 1:36
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Passing parameters in rails redirect_to
How do we pass parameters in redirect_to in rails?
I know we can pass id using this:
9 Answers
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load and execute order of scripts
There are so many different ways to include JavaScript in a html page. I know about the following options:
4 Answers
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Can I list-initialize a vector of move-only type?
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Now, I guess this should not be left without being mentioned in a comment :) move_only m[] = { move_only(), move_only(), move_only() }; std::vector<move_only> v(std::make_move_iterator(m), std::make_move_iterator(m + 3)...
set the width of select2 input (through Angular-ui directive)
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This is the best answer so far. But now, for me, the search field doesn't fill all the width. Any easy way to correct this?
– TNT
Dec 23 '17 at 22:39
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Add new field to every document in a MongoDB collection
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Pymongo 3.9+
update() is now deprecated and you should use replace_one(), update_one(), or update_many() instead.
In my case I used update_many() and it solved my issue:
db.your_collection.update_many({}, {"$set": {"new_field": "value"}}, upsert=Fa...
Detecting touch screen devices with Javascript
...t on devices with no touch input running a touch-capable browser. I don't know of a way to detect device touch capability natively, without just waiting for a touch event to occur.
– Stu Cox
Dec 12 '12 at 11:24
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Ninject vs Unity for DI [closed]
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This answer is now pretty irrelevant with reagrd to Ninject 2. Whilst the complaint was legitimate for Ninject 1, Ninject 2 allows one to work without littering there classes with attributes. ninject2 will operate transparently without th...