def flat_m(self, v):
return call_by_name(v) if self else maybe.Empty()
def m(self, v):
return maybe.Maybe(call_by_name(v)) if self else maybe.Empty()
def flat_maybe_call(self, f, *a, **kw):
return f(*a, **kw) if self else maybe.Empty()
def flat_maybe(self, value: 'Maybe'): # type: ignore
return value if self else maybe.Empty()
def maybe_call(self, f, *a, **kw):
return maybe.Just(f(*a, **kw)) if self else maybe.Empty()
def lift(self, index: int) -> 'maybe.Maybe[A]':
return ((maybe.Just(self[index])
if len(self) > index else maybe.Empty()) if index >= 0 else
(maybe.Just(self[index])
if len(self) >= -index else maybe.Empty()))
def maybe(self, value):
return maybe.Maybe(value) if self else maybe.Empty()
def tail(self) -> 'maybe.Maybe[List[A]]':
return maybe.Empty() if self.empty else maybe.Just(self[1:])
def init(self) -> 'maybe.Maybe[List[A]]':
return maybe.Empty() if self.empty else maybe.Just(self[:-1])
def find_map(self, fa: List[A], f: Callable[[A], Maybe[B]]) -> Maybe[B]:
for el in fa:
found = f(el)
if found.present:
return found
return maybe.Empty()
def tail(self) -> maybe.Maybe['List[A]']:
return maybe.Empty() if self.empty else maybe.Just(self[1:])
def init(self) -> maybe.Maybe['List[A]']:
return maybe.Empty() if self.empty else maybe.Just(self[:-1])
