split.swift

let string = "Lorem ipsum dolor sit amet, consectetur adipiscing elit. Morbi enim lacus, ullamcorper in gravida a, semper id dolor. Mauris quis metus id"

extension String {
    public func split(
        maxSplit: Int = .max,
        allowEmptySlices: Bool = false,
        @noescape isSeparator: ((Character) throws -> Bool)) rethrows -> [String] {
            
        return try self.characters.split(
            maxSplit,
            allowEmptySlices: allowEmptySlices,
            isSeparator: isSeparator)
            .map({String($0)})
    }
    
    public enum StringSplitError : ErrorType {case MissingCharacter}
    public func split(characterString: String) throws -> [String] {
        guard let c = characterString.characters.first else {
            throw StringSplitError.MissingCharacter
        }
        return self.split(isSeparator: {$0 == c})
    }
}

func dotry(block: () throws -> Void) {
    do {try block()} catch {print(error)}
}

dotry {
    let words = try string.split(" ")
    //let counts = lazy(words).map(count)
    let counts = words.lazy.map({$0.characters.count})
    print(Array(counts))
}