Simple highlighting with special characters

QuickHighlighting.swift

func highlighted(originalString: String, delimiter:[String]) -> NSMutableAttributedString? {

    if delimiter.count != 2 {
        return nil
    }

    let highlightedAttributes = [NSForegroundColorAttributeName: UIColor.redColor()]

    let searchString = originalString.componentsSeparatedByString(delimiter[0])
    var attributedResult = NSMutableAttributedString()

    for subString in searchString {
        let subComponents = subString.componentsSeparatedByString(delimiter[1])
        if subComponents.count > 1 {
            let coloredKeywordString = NSMutableAttributedString(string: subComponents[0], attributes: highlightedAttributes)
            attributedResult.appendAttributedString(coloredKeywordString)
            attributedResult.appendAttributedString(NSAttributedString(string: subComponents[1]))
        } else {
            attributedResult.appendAttributedString(NSAttributedString(string: subComponents[0]))
        }
    }

    return attributedResult
}