object
expected(Reference)
¶
Expected term reference predicates. Requires passing an expected reference constructed using the “expected” object as a parameter.
static, context_switching_calls
(no dependencies on other entities)
Public interface¶
is_unexpected/0
¶
True if the expected reference holds an unexpected term. Avoid whenever possible by using instead the if_unexpected/1 predicate.
static
is_unexpected
- zero_or_one
is_expected/0
¶
True if the expected reference holds an expected term. Avoid whenever possible by using instead the if_expected/1 predicate.
static
is_expected
- zero_or_one
if_unexpected/1
¶
Applies a closure, with the expected reference term as additional argument, if it holds an unexpected term. Succeeds otherwise.
static
if_unexpected(Closure)
if_unexpected(1)
if_unexpected(+callable)
- zero_or_more
if_expected/1
¶
Applies a closure, with the expected reference term as additional argument, if it does not hold an unexpected term. Succeeds otherwise.
static
if_expected(Closure)
if_expected(1)
if_expected(+callable)
- zero_or_more
unexpected/1
¶
Returns the unexpected reference term if not an expected term. Throws an error otherwise.
static
unexpected(Unexpected)
unexpected(--term)
- one
existence_error(unexpected_term,Reference)
expected/1
¶
Returns the expected reference term if not an unexpected term. Throws an error otherwise.
static
expected(Expected)
expected(--term)
- one
existence_error(expected_term,Reference)
map/2
¶
When the expected reference does not hold an unexpected term and mapping a closure with the expected reference term and the new term as additional arguments is successful, returns an expected reference with the new value. Otherwise returns the expected reference.
static
map(Closure,NewReference)
map(2,*)
map(+callable,--nonvar)
- one
flat_map/2
¶
When the expected reference does not hold an unexpected term and mapping a closure with the expected reference value and the new expected reference as additional arguments is successful, returns the new expected reference. Otherwise returns the expected reference.
static
flat_map(Closure,NewReference)
flat_map(2,*)
flat_map(+callable,--nonvar)
- one
or_else/2
¶
Returns the expected reference term if it does not hold an unexpected term or the given default term if the expected reference holds an unexpected term.
static
or_else(Term,Default)
or_else(--term,@term)
- one
or_else_get/2
¶
Returns the expected reference term if it does not hold an unexpected term or applies a closure to compute the term if the expected holds an unexpected term. Throws an error when the expected reference holds an unexpected term and a term cannot be computed using the given closure.
static
or_else_get(Term,Closure)
or_else_get(*,1)
or_else_get(--term,+callable)
- one
existence_error(expected_term,Reference)
or_else_call/2
¶
Returns the expected reference term if it does not hold an unexpected term or calls a goal deterministically if the expected reference holds an unexpected term. Can be used e.g. to throw the exception hold by the expected reference.
static
or_else_call(Expected,Goal)
or_else_call(*,0)
or_else_call(--term,+callable)
- zero_or_one
or_else_fail/1
¶
Returns the expected reference term if it does not hold an unexpected term. Fails otherwise. Usually called to skip over empty expected reference holding unexpected terms.
static
or_else_fail(Expected)
or_else_fail(--term)
- zero_or_one
Protected interface¶
(none)
Private predicates¶
(none)
Operators¶
(none)