There should be code completion after string literal and should offer fields and methods of String object.
The same should be applied for regex literals.
Created attachment 159252 [details]
Code Completion for String Literals
Now NetBeans offers code completion after a string literal. It offers nonstatic fields and methods from String object.
Also the signature file is updated to fit ECMAScript 6 specification. Some methods marked as deprecated, some added.
Created attachment 159253 [details]
Code Completion for RegExp Literals
NetBeans are able to offers public nonstatic fields and methods of RegExp object for regexp literals.
Also the runtime signature file for RegExp object was updated to fit ECMAScript 6 specification.
Done in ecma6-truffel branch.