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Tag: comparator

How do I map a Comparator to a Comparator using a Function?

I have a comparator of type Comparator<Integer> and a function Function<Pair<Integer,?>,Integer> expressed as Pair::left (that returns an Integer). I need to obtain a comparator of type Comparator<Pair<Integer,?>>. If I wanted to simply map a function Function<T,U> to a resulting function Function<T,V> though a function Function<U,V> I could simply apply andThen() method like this: Is it possible to obtain Comparator<Pair<Integer,?>> in

Create a SortedMap from a List objects with the Value represented as a list of N lowest object’s attributes mapped to a particular Key

I am working with a CSV file which includes some information about accidents. I’ve created the Accident type: I’ve also created a function that reads all the CSV file, converts all the accidents to a List<Accident> and saves it to this type AccidentArchive: So, we are working with streams which I don’t understand entirely yet, and I’ve been stuck in

Can’t pass wildcard Comparator to function

I have the following sort method in a clone of ArrayList: The sorter object is an instance of Sort: I get the following error on the sorter.mergeSort line: I’m not sure why this is happening as both the parameter and argument have type Comparator<? super E>. Answer Thanks to everyone for their comments. I’ve now fixed it. As Kayaman said,