Allow lazy implementations to raise from intrinsically eager functions (#652)

Author: cbourjau

src/array_api_stubs/_draft/array_object.py

@@ -241,6 +241,10 @@ def __bool__(self: array, /) -> bool:
 
         For complex floating-point operands, special cases must be handled as if the operation is implemented as the logical AND of ``bool(real(self))`` and ``bool(imag(self))``.
 
+        **Lazy implementations**
+
+        The Python language requires the return value to be of type ``bool``. Lazy implementations are therefore not able to return any kind of lazy/delayed object here and should raise a ``ValueError`` instead.
+
         .. versionchanged:: 2022.12
             Added boolean and complex data type support.
         """
@@ -276,6 +280,10 @@ def __complex__(self: array, /) -> complex:
         - If ``self`` is ``-infinity``, the result is ``-infinity + 0j``.
         - If ``self`` is a finite number, the result is ``self + 0j``.
 
+        **Lazy implementations**
+
+        The Python language requires the return value to be of type ``complex``. Lazy implementations are therefore not able to return any kind of lazy/delayed object here and should raise a ``ValueError`` instead.        
+
         .. versionadded:: 2022.12
         """
 
@@ -424,6 +432,10 @@ def __float__(self: array, /) -> float:
         - If ``self`` is ``True``, the result is ``1``.
         - If ``self`` is ``False``, the result is ``0``.
 
+        **Lazy implementations**
+
+        The Python language requires the return value to be of type ``float``. Lazy implementations are therefore not able to return any kind of lazy/delayed object here and should raise a ``ValueError`` instead.
+
         .. versionchanged:: 2022.12
             Added boolean and complex data type support.
         """
@@ -544,6 +556,13 @@ def __index__(self: array, /) -> int:
         -------
         out: int
             a Python ``int`` object representing the single element of the array instance.
+
+        Notes
+        -----
+
+        **Lazy implementations**
+
+        The Python language requires the return value to be of type ``int``. Lazy implementations are therefore not able to return any kind of lazy/delayed object here and should raise a ``ValueError`` instead.
         """
 
     def __int__(self: array, /) -> int:
@@ -582,6 +601,13 @@ def __int__(self: array, /) -> int:
         - If ``self`` is either ``+infinity`` or ``-infinity``, raise ``OverflowError``.
         - If ``self`` is ``NaN``, raise ``ValueError``.
 
+        Notes
+        -----
+
+        **Lazy implementations**
+
+        The Python language requires the return value to be of type ``int``. Lazy implementations are therefore not able to return any kind of lazy/delayed object here and should raise a ``ValueError`` instead.
+
         .. versionchanged:: 2022.12
             Added boolean and complex data type support.
         """