The following turtle sample fails to be parsed, because of the lack of whitespace between object: and the terminal dot:

@prefix test: <http://example.org/>.
@prefix object: <http://example.org/object>.
test:subject test:predicate object:.

In (my understanding of) the Turtle grammar, this is valid.
Turtle validator such as http://ttl.summerofcode.be concurs.

To the question : "why such a construct", the turtle serializer of linkeddata/rdflib.js f.i. does produce this.