Value

apfel.container.value provides a container that simply wraps a value designed to aid chained method calls.

See also Identity.

Value

apply(f)

Apply a function wrapped inside a Value to the inner value.

Parameters:

Name	Type	Description	Default
f	Value[Callable[[T], R]]	A Value containing a function to apply.	required

Returns:

Type	Description
Value[R]	A new Value containing the result of the function application.

bind(f)

Monadically bind a function that maps the inner value to a new Value.

Parameters:

Name	Type	Description	Default
f	Callable[[T], Value[R]]	A function that takes the inner value and returns a Value.	required

Returns:

Type	Description
Value[R]	A new Value containing the result of the function.

done()

Return the value wrapped inside the container.

Unlike unwrap methods on other containers, this method will never raise exceptions.

map(f)

Map a function over the Value container.

pipe(func)

pipe(func: Callable[[T], T]) -> Self

pipe(func: Callable[[T], None]) -> Self

Run a function to process the inner value. If a result is produced, the result will be put back to the container. Otherwise, the original reference within the container will be kept.

Warning

Compare to Value.map, this method mutates the container in place. No new container is created. Therefore, the function must return a result of the same type as the previous inner type of the container, or return None.

Parameters:

Name	Type	Description	Default
func	Callable[[T], T] | Callable[[T], None]	A function to process the value.	required

Returns:

Type	Description
Value[T]	The mutated container itself.

pure(x) classmethod

pure(value: R) -> Value[R]

pure(value: T) -> Value[T]

Wrap a value into the Value container.

Parameters:

Name	Type	Description	Default
x	T	The value to wrap.	required

Returns:

Type	Description
Value[T]	A new instance of Value with the value wrapped.

run(func)

Run a function to process the inner value, and return the result.

Parameters:

Name	Type	Description	Default
func	Callable[[T], R]	A function to process the value.	required

Returns:

Type	Description
R	The result of the function.

tap(func)

Call a function over the inner value, ignore the return value, and return the original container.

See also also.

Warning

Pragmatically, the function shouldn't mutate the inner value. Use the Value.pipe method instead.