Udacity iOS emoji textfield, functionally seasoned

EmojiTextFieldDelegate.swift

//
//  EmojiTextFieldDelegate.swift
//  TextFields
//
//  Created by Jason on 11/11/14.
//  Copyright (c) 2014 Udacity. All rights reserved.
//

import Foundation
import UIKit

// MARK: - EmojiTextFieldDelegate : NSObject, UITextFieldDelegate

class EmojiTextFieldDelegate : NSObject, UITextFieldDelegate {

    // MARK: Properties
    
    var translations = [String : String]()
    
    // MARK: Initializer
    
    override init() {
        super.init()
        
        translations["heart"] = "\u{0001F496}"
        translations["fish"] = "\u{E522}"
        translations["bird"] = "\u{E523}"
        translations["frog"] = "\u{E531}"
        translations["bear"] = "\u{E527}"
        translations["dog"] = "\u{E052}"
        translations["cat"] = "\u{E04F}"
    }
    
    // MARK: When TextField Changes
    
    func textField(textField: UITextField, shouldChangeCharactersInRange range: NSRange, replacementString string: String) -> Bool {

        let replacedText = (textField.text! as NSString).stringByReplacingCharactersInRange(range, withString: string);

        // For each dictionary entry in translations, pull out a string to search for and an emoji to replace it with
        let translatedText=translations.reduce(replacedText as String) {
            $0.stringByReplacingOccurrencesOfString($1.0, withString: $1.1, options: NSStringCompareOptions.CaseInsensitiveSearch)
        }
        textField.text = translatedText;
        return false;
    }
 
    func textFieldDidBeginEditing(textField: UITextField) {
        textField.text = ""
    }
}