text: var Validation;
  (function (Validation) {
      var lettersRegexp = /^[A-Za-z]+$/;
      var numberRegexp = /^[0-9]+$/;
      // export class LettersOnlyValidator implements StringValidator {
      //     isAcceptable(s: string) {
      //         return lettersRegexp.test(s);
      //     }
      // }
      // export class ZipCodeValidator implements StringValidator {
      //     isAcceptable(s: string) {
      //         return s.length === 5 && numberRegexp.test(s);
      //     }
      // }
  })(Validation || (Validation = {}));
  // Some samples to try
  // let strings = ["Hello", "98052", "101"];
  // // Validators to use
  // let validators: { [s: string]: Validation.StringValidator } = {};
  // validators["ZIP code"] = new Validation.ZipCodeValidator();
  // validators["Letters only"] = new Validation.LettersOnlyValidator();
  // // Show whether each string passed each validator
  // for (let s of strings) {
  //   for (let name in validators) {
  //     console.log(
  //       `"${s}" - ${
  //         validators[name].isAcceptable(s) ? "matches" : "does not match"
  //       } ${name}`
  //     );
  //   }
  // }
  