#swift #array #collections

array.swift

let names = ["Paul", "Elena", "Zoe"]

extension Sequence {
    func last(where predicate: (Iterator.Element) -> Bool) -> Iterator.Element? {
        for element in reversed() where predicate(element) {
            return element
        }
        return nil
    }
}

let match = names.last { $0.hasSuffix("a") }
match


extension Array {
    func accumulate<Result>(_ initialResult: Result,
                            _ nextPartialRequest: (Result, Element) -> Result) -> [Result] {
        var running = initialResult
        return map { next in
            running = nextPartialRequest(running, next)
            return running
        }
    }
}

[1,2,3,4].accumulate(0, +)