chooseShorthand<T> function

T? chooseShorthand<T>(String message, Iterable<T> options, { T? defaultsTo, bool chevron = true, @deprecated bool colon = true, AnsiCode inputColor = cyan, bool color = true, bool conceal = false, })

Similar to choose, but opts for a shorthand syntax that fits into one line, rather than a multi-line prompt.

Acceptable inputs include:

• The full value of toString() for any one option
• The first character (case-insensitive) of toString() for an option

A default option may be provided by means of defaultsTo.

color, defaultsTo, inputColor, and chevron are forwarded to get.

Implementation

T? chooseShorthand<T>(String message, Iterable<T> options,
    {T? defaultsTo,
    bool chevron = true,
    @deprecated bool colon = true,
    AnsiCode inputColor = cyan,
    bool color = true,
    bool conceal = false}) {
  if (options.isEmpty) {
    throw ArgumentError.value('`options` may not be empty.');
  }

  var b = StringBuffer(message);
  if (chevron && colon) b.write(':');
  b.write(' (');
  var firstChars = <String>[], strings = <String>[];
  var i = 0;

  for (var option in options) {
    var str = option.toString();
    if (i++ > 0) b.write('/');

    if (defaultsTo != null) {
      if (defaultsTo == option) {
        str = str[0].toUpperCase() + str.substring(1);
      } else {
        str = str[0].toLowerCase() + str.substring(1);
      }
    }

    b.write(str);
    firstChars.add(str[0].toLowerCase());
    strings.add(str);
  }

  b.write(')');

  T? value;

  get(
    b.toString(),
    chevron: chevron && colon,
    inputColor: inputColor,
    color: color,
    conceal: conceal,
    validate: (s) {
      if (s.isEmpty) return (value = defaultsTo) != null;

      if (strings.contains(s)) {
        value = options.elementAt(strings.indexOf(s));
        return true;
      }

      if (firstChars.contains(s[0].toLowerCase())) {
        value = options.elementAt(firstChars.indexOf(s[0].toLowerCase()));
        return true;
      }

      return false;
    },
  );

  return value;
}