Add an implicit scalar detector.
    If an implicit scalar value matches the given regexp,
    the corresponding tag is assigned to the scalar.
    first is a sequence of possible initial characters or None.

def add_implicit_resolver(tag, regexp, first=None,
        Loader=Loader, Dumper=Dumper):
    """
    Add an implicit scalar detector.
    If an implicit scalar value matches the given regexp,
    the corresponding tag is assigned to the scalar.
    first is a sequence of possible initial characters or None.
    """
    Loader.add_implicit_resolver(tag, regexp, first)
    Dumper.add_implicit_resolver(tag, regexp, first)