Support range sequences in index_of

CHANGELOG.rst

@@ -6,6 +6,7 @@ Changelog
 Unreleased
 ----------
 
+- Support ``range`` objects in ``index_of``, including when a start index is supplied.
 - Merge nested mutable mappings in place instead of replacing their existing contents, including
   ``UserDict`` and ``ChainMap``, and apply deep defaults and customizers to their entries.
 - Allow sort directions in ``order_by`` to be iterables without a truth value.

src/pydash/arrays.py

@@ -799,6 +799,18 @@ def index_of(array: t.Sequence[T], value: T, from_index: int = 0) -> int:
 
     .. versionadded:: 1.0.0
     """
+    if isinstance(array, range):
+        # range.index does not accept a starting index. Slicing preserves
+        # range's arithmetic search without materializing the sequence.
+        tail = array[from_index:]
+        # At runtime range.index also accepts objects that compare equal to an int.
+        searchable_tail: Sequence[object] = tail
+        try:
+            index = searchable_tail.index(value)
+        except ValueError:
+            return -1
+        return array.index(tail.start) + index
+
     try:
         return array.index(value, from_index)
     except ValueError:

tests/test_arrays.py

@@ -480,6 +480,26 @@ def test_index_of(case, value, from_index, expected):
     assert _.index_of(case, value, from_index) == expected
 
 
+@parametrize(
+    "sequence,value,start,expected",
+    [
+        (range(10, 20, 2), 14, 0, 2),
+        (range(10, 20, 2), 14, 3, -1),
+        (range(10, 20, 2), 14, -3, 2),
+        (range(10, 20, 2), 14, -2, -1),
+        (range(10, 20, 2), 14, -100, 2),
+        (range(20, 10, -2), 14, 2, 3),
+        (range(10, 20, 2), 14, 100, -1),
+        (range(10, 20, 2), 15, 0, -1),
+        (range(10, 20, 2), 14.0, 0, 2),
+        (range(0), 0, 0, -1),
+        (range(10**30), 10**30 - 1, -2, 10**30 - 1),
+    ],
+)
+def test_index_of_range(sequence, value, start, expected):
+    assert _.index_of(sequence, value, start) == expected
+
+
 @parametrize("case,expected", [([1, 2, 3], [1, 2]), ([1], [])])
 def test_initial(case, expected):
     assert _.initial(case) == expected