String+Hankana.swift

import Foundation

extension String {
    var hankanaRange : NSRange {
        get {
            return String.rangeOfHankana(self)
        }
    }
    var stringWithoutHankana : String {
        get {
            var str = self
            var range = NSMakeRange(NSNotFound, 0)
            repeat {
                range = String.rangeOfHankana(str)
                str = String.convHan2Zen(str, range: range)
            } while ( range.location != NSNotFound )
            return str
        }
    }
    static func rangeOfHankana(str:String) -> NSRange {
        var location = NSNotFound
        var length = 0
        var i = 0
        let range = NSMakeRange(0xff61,0xff9f - 0xff61)
        let characterSet = NSCharacterSet(range: range)
        for c in str.utf16 {
            if location == NSNotFound {
                if characterSet.characterIsMember(c) {
                    location = i
                    length = 1
                } else {
                    
                }
            } else {
                if characterSet.characterIsMember(c) {
                    length += 1
                } else {
                    break
                }
            }
            i += 1
        }
        return NSMakeRange(location, length)
    }
    static func convHan2Zen(string:String, range:NSRange) -> String {
        let str = NSMutableString(string: string)
        var cfr = CFRangeMake(range.location == NSNotFound ? kCFNotFound : range.location, range.length)
        CFStringTransform(str, &cfr, kCFStringTransformFullwidthHalfwidth, true)
        return str as String
    }
}