var split:Array = someString.split(/\./);
which will of course split "someString" using "." as a delimeter. Of course, all that's really happening is that the regular expression is being converted to an object by the compiler, so the following is the same:
var regexp:RegExp = /\./;
var split:Array = someString.split(regexp);
This is superiour to Java's approach which allows you to specify a regular expression as a String when calling split, the problem being that the above regexp would look like this:
String regExp = "/\\./";
Note how I have to escape the escape character!
Of course, Java has a whole package for regular expression handling, but they all suffer the same problem of having to encode the regular expression in a string and thus having to escape the escape characters... which makes long regular expressions very complicated and as a result I suspect a lot of Java developers simply avoid using regular expressions for that reason. In my view inlining regular expressions is definately a candidate for being added to the core Java language.