Swift で unicode NFC の normalize

swift

s.precomposedStringWithCanonicalMapping

あとカタカナ/ひらがな 変換

swift

import Foundation

extension String {
    // MARK: Public Methods

    // ひらがな→カタカナ
    func hiraganaToKatakana() -> String {
        return self.transform(transform: .hiraganaToKatakana, reverse: false)
    }

    // MARK: Private Methods

    private func transform(transform: StringTransform, reverse: Bool) -> String {
        if let string = self.applyingTransform(transform, reverse: reverse) {
            return string
        } else {
            return ""
        }
    }
}