object
Constructors for optional term references. An optional reference represents a term that may or may not be present. Optional references should be regarded as opaque terms and always used with the "optional(_)" object by passing the reference as a parameter.
Paulo Moura
1.2
2017/8/8
static, context_switching_calls
type::type/1
type::check/2
Constructs an empty optional reference.
static
empty(Reference)
empty(--nonvar) – one
Constructs an optional reference from a term.
static
of(Term,Reference)
of(@term,--nonvar) – one
(see related entities)
(see related entities)