object
optional
¶
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.
Author: Paulo Moura
Version: 1.2
Date: 2017/8/8
Compilation flags:
static, context_switching_calls
Provides:
Public interface¶
empty/1
¶
Constructs an empty optional reference.
Compilation flags:
static
Template:
empty(Reference)
Mode and number of proofs:
empty(--nonvar)
- one
of/2
¶
Constructs an optional reference from a term.
Compilation flags:
static
Template:
of(Term,Reference)
Mode and number of proofs:
of(@term,--nonvar)
- one
Protected interface¶
(see related entities)
Private predicates¶
(see related entities)
Operators¶
(none)
Remarks¶
- Type-checking support: This object also defines a type “optional” for use with the “type” library object.
See also