I have a very simple example of a set s1 {1, 2} and I want to apply a predicate p > 1 on it. Now I have implemented this function, and it is giving me correct results.
def filter(s: Set, p: Int => Boolean): Set = {(i: Int) => s(i) && p(i)}
Where definition of set is
type Set = Int => Boolean
But is there a more elegant way of doing it in Scala?
Using this course's definition of what a Set is, your answer is very elegant.
Since the predicate is in fact a Set too, filter could have been much more terse by reusing the intersect function:
/**
* Returns the intersection of the two given sets,
* the set of all elements that are both in `s` and `t`.
*/
def intersect(s: Set, t: Set): Set = ???
/**
* Returns the subset of `s` for which `p` holds.
*/
def filter(s: Set, p: Int => Boolean): Set = intersect(s, p)
I left the intersect implementation out because the Coursera Honor Code prevents sharing assignment answers.
Setlike this and not use standard Scala collection library?{}and the type annotation afteri, so the body would look like this:i => s(i) && p(i). Other than that it looks fine... :)iby the way, because it is inferred.def filter(s: Set)(p: Int => Boolean): Set = { i => s(i) && p(i) }