export interface StringValidator {
    isAcceptable(s: string): boolean;
}

export const numberRegexp = /^[0-9]+$/;

export class ZipCodeValidator implements StringValidator {
    isAcceptable(s: string) {
        return s.length === 5 && numberRegexp.test(s);
    }
}

class ZipCodeValidator implements StringValidator {
    isAcceptable(s: string) {
        return s.length === 5 && numberRegexp.test(s);
    }
}
export { ZipCodeValidator };
export { ZipCodeValidator as mainValidator };

// a module can wrap one or more modules and combine all their exports using export * from "module" syntax.
export * from "./StringValidator"; // exports interface 'StringValidator'
export * from "./LettersOnlyValidator"; // exports class 'LettersOnlyValidator'
export * from "./ZipCodeValidator";  // exports class 'ZipCodeValidator'