object
expected
¶
Constructors for expected terms. An expected term contains either a value or an error. Expected terms should be regarded as opaque terms and always used with the expected/1
object by passing the expected term as a parameter.
static, context_switching_calls
Type-checking support: This object also defines a type
expected
for use with thetype
library object.
Public predicates¶
of_unexpected/2
¶
Constructs an expected term from an error that represent that the expected value is missing.
static
of_unexpected(Error,Expected)
of_unexpected(@term,--nonvar)
- one
of_expected/2
¶
Constructs an expected term from an expected value.
static
of_expected(Value,Expected)
of_expected(@term,--nonvar)
- one
from_goal/4
¶
Constructs an expected term holding a value bound by calling the given goal. Otherwise returns a reference with the unexpected goal error or failure represented by the Error
argument.
static
from_goal(Goal,Value,Error,Expected)
from_goal(0,*,*,*)
from_goal(+callable,--term,@term,--nonvar)
- one
from_goal/3
¶
Constructs an expected term holding a value bound by calling the given goal. Otherwise returns an expected term with the unexpected goal error or, in case of closure goal, the atom fail
.
static
from_goal(Goal,Value,Expected)
from_goal(0,*,*)
from_goal(+callable,--term,--nonvar)
- one
from_goal/2
¶
Constructs an expected term holding a value bound by calling the given closure. Otherwise returns an expected term holding the unexpected closure error or, in case of closure failure, the atom fail
.
static
from_goal(Closure,Expected)
from_goal(1,*)
from_goal(+callable,--nonvar)
- one
Protected predicates¶
(no local declarations; see entity ancestors if any)
Private predicates¶
(no local declarations; see entity ancestors if any)