Rather than having a special RangeExpression 0..5 we could just make .. an operator. Then the .. operator on numbers could create a range and we can use this operator to do a 'traverse' on other objects. E.g. we can use .. to be like // in XPath. e.g. node = builder.foo() { bar() { x("a") x("b") } } node..x would yield [ x("a"), x("b") ] We could also use .. to invoke methods on collections of objects too. node..x..name() would yield ["a", "b"]