def add_implicit_resolver(tag, regexp, first=None,<EOL>Loader=Loader, Dumper=Dumper):
Loader.add_implicit_resolver(tag, regexp, first)<EOL>Dumper.add_implicit_resolver(tag, regexp, first)<EOL>
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.