split.swift

// Split
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{$0 == c}
    }
}