Typing updates 2026

docs/api.md

@@ -31,6 +31,9 @@
 ::: iterum.Nil
 ::: iterum.nil
 
+::: iterum.is_some
+::: iterum.is_nil
+
 ::: iterum.ExpectNilError
 ::: iterum.UnwrapNilError
 

src/iterum/__init__.py

@@ -23,7 +23,17 @@
     Zip,
     iterum,
 )
-from ._option import ExpectNilError, Nil, Option, Some, Swap, UnwrapNilError, nil
+from ._option import (
+    ExpectNilError,
+    Nil,
+    Option,
+    Some,
+    Swap,
+    UnwrapNilError,
+    is_nil,
+    is_some,
+    nil,
+)
 from ._ordering import Ordering
 from ._seq import InfSeq, Seq, seq
 
@@ -42,6 +52,8 @@
     "nil",
     "ExpectNilError",
     "UnwrapNilError",
+    "is_nil",
+    "is_some",
     # Ordering
     "Ordering",
     # special Iterum implementations

src/iterum/_diterum.py

@@ -1,9 +1,8 @@
-from __future__ import annotations
-
 from abc import abstractmethod
 from collections.abc import Callable, Sequence
+from typing import override
 
-from ._iterum import Iterum, T_co, U
+from ._iterum import Iterum, T_co
 from ._option import Option, Some, nil
 
 
@@ -202,7 +201,7 @@ def rfind(self, predicate: Callable[[T_co], object], /) -> Option[T_co]:
         """
         return self.rev().find(predicate)
 
-    def rfold(self, init: U, f: Callable[[U, T_co], U], /) -> U:
+    def rfold[U](self, init: U, f: Callable[[U, T_co], U], /) -> U:
         """
         A diterum method that reduces the diterum's elements to a single,
         final value, starting from the back.
@@ -241,7 +240,7 @@ def rfold(self, init: U, f: Callable[[U, T_co], U], /) -> U:
         """
         return self.rev().fold(init, f)
 
-    def try_rfold(
+    def try_rfold[U](
         self,
         init: U,
         f: Callable[[U, T_co], U],
@@ -278,12 +277,15 @@ class Rev(Diterum[T_co]):
     def __init__(self, __x: Diterum[T_co] | Sequence[T_co]) -> None:
         self._x = __x if isinstance(__x, Diterum) else diterum(__x)
 
+    @override
     def next(self) -> Option[T_co]:
         return self._x.next_back()
 
+    @override
     def next_back(self) -> Option[T_co]:
         return self._x.next()
 
+    @override
     def len(self) -> int:
         return self._x.len()
 
@@ -331,6 +333,7 @@ def __init__(self, __seq: Sequence[T_co], /) -> None:
         self._front = 0
         self._back = len(__seq) - 1
 
+    @override
     def next(self) -> Option[T_co]:
         """
         Returns the next value in the sequence from the front if present,
@@ -354,6 +357,7 @@ def next(self) -> Option[T_co]:
         self._front += 1
         return Some(nxt)
 
+    @override
     def next_back(self) -> Option[T_co]:
         """
         Returns the next value in the sequence from the back if present,
@@ -377,6 +381,7 @@ def next_back(self) -> Option[T_co]:
         self._back -= 1
         return Some(nxt)
 
+    @override
     def len(self) -> int:
         """
         Returns the remaining length of the sequence.