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
def _map(self, f: Callable):
g = List.wrap(range(self.depth)).fold_left(f)(lambda z, i: __.map(z))
return g(self.value)
def map(self, f: Callable):
return self.copy(self._map(__.map(f)))
from typing import TypeVar, Callable
from lenses import Lens, lens
from tryp import Maybe, List, __, Boolean, _, L
A = TypeVar('A')
_add = lambda l: __.map(lens().add_lens(l).add_lens)
def path_lens_pred(a: A, sub: Callable[[A], List[A]], lsub,
f: Callable[[A], bool]):
g = lambda a: Boolean(f(lsub(a))).maybe(lsub(lens()))
return path_lens(a, sub, g)
def path_lens(a: A, sub: Callable[[A], List[A]],
f: Callable[[A], Maybe[Lens]]) -> Maybe[Lens]:
return _path_lens(a, sub, f).smap(lens(a).tuple_)
def path_lens_unbound_pre(a: A, sub: Callable[[A], List[A]],
f: Callable[[A], Maybe[Lens]], pre: Callable):
return (
_path_lens(pre(a), sub, f) /
(_ / pre(lens()).add_lens) /
__.cons(lens())
).smap(lens().tuple_)