GH-39: add min and max methods

magic_list/prelude.py

@@ -540,6 +540,50 @@ def mean(self: list[int] | list[float] | list[complex]) -> float | complex:
 
         return sum(self) / len(self)
 
+    def min(self: list[int] | list[float]) -> int | float:
+        """
+        Return the minimum value of the list.
+
+        .. warning:: The list must be non-empty and contain numbers.
+
+        >>> L[3, 5, 2].min()
+        2
+        >>> L["hello", "world"].min()
+        *- TypeError: list of str has no minimum -*
+        >>> list().min()
+        *- TypeError: empty list has no minimum -*
+        """
+
+        if not self:
+            raise TypeError("empty list has no minimum")
+
+        if not isinstance(self.head, (int, float)):  # pyright: ignore[reportUnnecessaryIsInstance]
+            raise TypeError(f"list of {type(self.head).__name__} has no minimum")
+
+        return min(self)
+
+    def max(self: list[int] | list[float]) -> int | float:
+        """
+        Return the maximum value of the list.
+
+        .. warning:: The list must be non-empty and contain numbers.
+
+        >>> L[3, 5, 2].max()
+        2
+        >>> L["hello", "world"].max()
+        *- TypeError: list of str has no maximum -*
+        >>> list().max()
+        *- TypeError: empty list has no maximum -*
+        """
+
+        if not self:
+            raise TypeError("empty list has no maximum")
+
+        if not isinstance(self.head, (int, float)):  # pyright: ignore[reportUnnecessaryIsInstance]
+            raise TypeError(f"list of {type(self.head).__name__} has no maximum")
+
+        return max(self)
+
     def fill_left(
         self,
         filler: _T | collections.abc.Callable[[list[_T]], _T],

magic_list/prelude.pyi

@@ -103,6 +103,14 @@ class list[_T](collections.UserList[_T]):
     def mean(self: list[complex]) -> complex: ...
     @typing.overload
     def mean(self) -> typing_extensions.Never: ...
+    @typing.overload
+    def min[NumberT: int | float | complex](self: list[NumberT]) -> NumberT: ...
+    @typing.overload
+    def min(self) -> typing_extensions.Never: ...
+    @typing.overload
+    def max[NumberT: int | float](self: list[NumberT]) -> NumberT: ...
+    @typing.overload
+    def max(self) -> typing_extensions.Never: ...
     # *- expansion-based HOFs -* #
     @typing.overload
     def fill_left(self, filler: _T, n: int) -> typing_extensions.Self: ...

tests/list_test.py

@@ -630,6 +630,56 @@ def test_sum_err(prebuild_list, exception, message):
         prebuild_list.sum()
 
 
+@pytest.mark.parametrize(
+    ["prebuild_list", "result"],
+    [
+        ["list_int_filled", -1],
+        ["list_one_int", 42],
+    ],
+    indirect=["prebuild_list"],
+)
+def test_min_ok(prebuild_list, result):
+    assert prebuild_list.min() == result
+
+
+@pytest.mark.parametrize(
+    ["prebuild_list", "exception", "message"],
+    [
+        ["list_str_filled", TypeError, "list of str has no minimum"],
+        ["list_empty", TypeError, "empty list has no minimum"],
+    ],
+    indirect=["prebuild_list"],
+)
+def test_min_err(prebuild_list, exception, message):
+    with pytest.raises(exception, match=message):
+        prebuild_list.min()
+
+
+@pytest.mark.parametrize(
+    ["prebuild_list", "result"],
+    [
+        ["list_int_filled", 20],
+        ["list_one_int", 42],
+    ],
+    indirect=["prebuild_list"],
+)
+def test_max_ok(prebuild_list, result):
+    assert prebuild_list.max() == result
+
+
+@pytest.mark.parametrize(
+    ["prebuild_list", "exception", "message"],
+    [
+        ["list_str_filled", TypeError, "list of str has no maximum"],
+        ["list_empty", TypeError, "empty list has no maximum"],
+    ],
+    indirect=["prebuild_list"],
+)
+def test_max_err(prebuild_list, exception, message):
+    with pytest.raises(exception, match=message):
+        prebuild_list.max()
+
+
 @pytest.mark.parametrize(
     ["prebuild_list", "result"],
     [