             attributedString.addAttribute(NSForegroundColorAttributeName, value: textColor!, range: textRange)
             attributedString.addAttribute(NSFontAttributeName, value: font!, range: textRange)
 
-            // mention link
+            // mention highlight
 
             let mentionPattern = "[@＠]([A-Za-z0-9_]{4,16})"
 

    }
}

extension FeedTextView: UITextViewDelegate {

    func textView(textView: UITextView, shouldInteractWithURL URL: NSURL, inRange characterRange: NSRange) -> Bool {

        guard let detectionTypeName = self.attributedText.attribute(ChatTextView.detectionTypeName, atIndex: characterRange.location, effectiveRange: nil) as? String, detectionType = DetectionType(rawValue: detectionTypeName) else {
            return true
        }

        let text = (self.text as NSString).substringWithRange(characterRange)

        self.hangleTapText(text, withDetectionType: detectionType)

        return true
    }

    private func hangleTapText(text: String, withDetectionType detectionType: DetectionType) {

        println("hangleTapText: \(text), \(detectionType)")

        let username = text.substringFromIndex(text.startIndex.advancedBy(1))

        if !username.isEmpty {
            tapMentionAction?(username: username)
        }
    }
}

            mentionExpression.enumerateMatchesInString(text, options: NSMatchingOptions(), range: textRange, usingBlock: { result, flags, stop in

                if let result = result {

                    let textAttributes: [String: AnyObject] = [
                        NSForegroundColorAttributeName: UIColor.redColor(),
                    ]

                    attributedString.addAttributes(textAttributes, range: result.range )
