✨: add HasArrayLShift protocol to support left shift operator for array classes

Author: nstarman

src/array_api_typing/_array.py

@@ -252,6 +252,22 @@ def __xor__(self, other: Self | int | float, /) -> Self:
         ...
 
 
+class HasArrayLShift(Protocol):
+    """Protocol for array classes that support the left shift operator."""
+
+    def __lshift__(self, other: Self | int, /) -> Self:
+        """Calculates the left shift for each element of an array instance with the respective element of the array other.
+
+        Args:
+            other: operand array. Must be compatible with self (see Broadcasting). Should have an integer data type.
+
+        Returns:
+            an array containing the element-wise left shifts. The returned array must have a data type determined by Type Promotion Rules.
+
+        """  # noqa: E501
+        ...
+
+
 class Array(
     HasArrayNamespace[NS_co],
     HasArrayPos,
@@ -268,6 +284,7 @@ class Array(
     HasArrayAnd,
     HasArrayOr,
     HasArrayXOr,
+    HasArrayLShift,
     Protocol,
 ):
     """Array API specification for array object attributes and methods."""