System Info

according to the implementations of the Constraint ABC, the advance() function can return either a single token id (as the docstring indicates) or a list of token ids that would advance the beam search. It should be updated to reflect this.

Here is an example fix:

@abstractmethod
def advance(self):
    """
    When called, returns the token(s) that would take this constraint one step closer to being fulfilled.

    Return:
        token_ids (Union[int, List[int], None]): 
            - A single token ID (int) that advances the constraint
            - A list of token IDs that could advance the constraint
            - None if the constraint is completed or cannot be advanced
    """

Who can help?

No response

Information

• The official example scripts
• My own modified scripts

Tasks

• An officially supported task in the examples folder (such as GLUE/SQuAD, ...)
• My own task or dataset (give details below)

Reproduction

Just a docstring change.

Expected behavior

Should be updated for accuracy, easy of implementing this abstract base class.