Better Module Visibility Rules

TypeScript now only strictly enforces the visibility of types in modules if the —declaration flag is provided. This is very useful for Angular scenarios, for example:

module MyControllers {
  interface ZooScope extends ng.IScope {
    animals: Animal[];
  }
  export class ZooController {
    // Used to be an error (cannot expose ZooScope), but now is only
    // an error when trying to generate .d.ts files
    constructor(public $scope: ZooScope) { }
    /* more code */
  }
}