def _flat_map(self, f: Callable):
''' **f** must return the same stack type as **self.value** has.
Iterates over the effects, sequences the inner instance
successively to the top and joins with the outer instance.
Example:
List(Right(Just(1))) => List(Right(Just(List(Right(Just(5))))))
=> List(List(Right(Just(Right(Just(5))))))
=> List(Right(Just(Right(Just(5)))))
=> List(Right(Right(Just(Just(5)))))
=> List(Right(Just(Just(5))))
=> List(Right(Just(5)))
Note: Task works only as outermost effect, as it cannot sequence
'''
index = List.range(self.depth + 1)
g = index.fold_left(f)(lambda z, i: __.map(z))
nested = g(self.value)
def sequence_level(z, depth, tpe):
nesting = lambda z, i: __.map(z).sequence(tpe)
lifter = List.range(depth).fold_left(I)(nesting)
return z // lifter
def sequence_type(z, data):
return L(sequence_level)(_, *data).map(z)
h = self.all_effects.reversed.with_index.fold_left(I)(sequence_type)
return h(nested)
def sequence_level(z, depth, tpe):
nesting = lambda z, i: __.map(z).sequence(tpe)
lifter = List.range(depth).fold_left(I)(nesting)
return z // lifter
