librdf_new_uri -- Constructor - create a new librdf_uri object from a URI string
librdf_new_uri_from_uri -- Copy constructor - create a new librdf_uri object from an existing librdf_uri object
librdf_new_uri_from_uri_local_name -- Copy constructor - create a new librdf_uri object from an existing librdf_uri object and a local name
librdf_new_uri_normalised_to_base -- Constructor - create a new librdf_uri object from a URI string stripped of the source URI, made relative to the base URI