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Declaration and parameters
링크사용 조건
기본 포함 · 미정
Import std.test in language mode 5.21.
The current compiler selects std/test.tpz for this language mode. Availability in other released editions and inclusion in each installed distribution are Pending.
수신자
매개변수 제약
assert accepts an Option<T> and returns the T payload of Some(value). Passing None() raises TPZ4007.
assert accepts an Option<T> and returns unit for None(). Passing Some(value) raises TPZ4007.
Presence depends on the outer constructor. Some(None()), Some(false), and Some(0) are present values. assertSome returns their payloads unchanged.
Each argument is evaluated once. A successful assertion prints nothing and performs no additional effects. Failure reports the assertion call and stops the current test before its next statement.
The failure messages identify the unexpected constructor. A present payload uses ordinary value rendering.
assertSome failed: got None
assertNone failed: got Some({value})Use a match to handle absence as normal program behavior. These assertions report a failed test when the chosen presence expectation is false.
관련 규칙 · Assert presence or absence →결과
The declared result type is ().
효과
실패
Result and effects
링크Return unit for an absent outer option. A present outer option raises TPZ4007 with its payload.
Related entries
링크Assert presence or absence
링크Assert presence or absence
assert accepts an Option<T> and returns the T payload of Some(value). Passing None() raises TPZ4007.
assert accepts an Option<T> and returns unit for None(). Passing Some(value) raises TPZ4007.
Presence depends on the outer constructor. Some(None()), Some(false), and Some(0) are present values. assertSome returns their payloads unchanged.
Each argument is evaluated once. A successful assertion prints nothing and performs no additional effects. Failure reports the assertion call and stops the current test before its next statement.
The failure messages identify the unexpected constructor. A present payload uses ordinary value rendering.
assertSome failed: got None
assertNone failed: got Some({value})Use a match to handle absence as normal program behavior. These assertions report a failed test when the chosen presence expectation is false.
이유
Outer constructor checks keep absence separate from a stored false, zero, or absent nested value. They give tests the same Option meaning as ordinary pattern matching.
Distinguish nested absence from an absent outer value
링크import std.testimport std.iolet present: Option<int> = Some(7)let absent: Option<int> = None()let nested: Option<Option<int>> = Some(None())let value = test.assertSome(present)let result: () = test.assertNone(absent)test.assertNone(test.assertSome(nested))io.writeLine("{value}/{result}")
7/()
기대 결과
기대 결과
실행을 마칩니다. 종료 코드 0.
7/()
Fail assertSome on an absent value
링크import std.testimport std.iolet value: Option<int> = None()io.writeLine("before")test.assertSome(value)io.writeLine("after")
before
기대 결과
Fail assertNone with the present payload
링크import std.testimport std.iolet value: Option<int> = Some(7)io.writeLine("before")test.assertNone(value)io.writeLine("after")
before