Creates a new bocage object, with a reference count of 1. The reference count of its parent recognizer object, r, is increased by 1. If earley_set_ID is -1, the Earley set at the current earleme is used, if there is one.
If earley_set_ID is -1
and there is no Earley set at the current earleme;
or if earley_set_ID is -1
and there is no parse ending at Earley set earley_set_ID,
and the error code is set to
Success return value: On success, the new bocage object.