dropFirstLast.swift

extension BidirectionalCollection {
  func drop(first: Int, last: Int) -> SubSequence {
    return self.dropFirst(first).dropLast(last)
  }
}

let numbers = 0..<10
numbers.drop(first: 1, last: 1)  // 1..<9
numbers.drop(first: 2, last: 4)  // 2..<6

I'm wondering what's the reason for the use of BidirectionalCollection instead of Collection. 😉

🤔 Maybe because if we extend Collection we'd be able to do

let set = Set(arrayLiteral: 1,2,3,4,5).drop(first: 1, last: 3)
let dictionary = [1:2, 2:3, 4:5].drop(first: 1, last: 3)

which does not seem to make much sense