.onChange(of: textInput) { old, new in
   let tagger = NLTagger(tagSchemes: [.sentimentScore])
   tagger.string = new

   let (tag, _) = tagger.tag(at: new.startIndex, unit: .paragraph, scheme: .sentimentScore)
   if let tag = tag {
      let mood = Double(tag.rawValue) ?? 0
      switch mood {
         case -1.0 ... -0.5:
            message = "\u{1F621}"
         case 0.5 ... 1.0:
            message = "\u{1F602}"
         default:
            message = "\u{1F611}"
      }
   }
}