Update docs

python/ql/src/Functions/examples/IncorrectRaiseInSpecialMethod.py

@@ -0,0 +1,22 @@
+class A:
+    def __init__(self, a):
+        self.a = a 
+
+    def __add__(self, other):
+        # BAD: Should return NotImplemented instead of raising
+        if not isinstance(other,A):
+            raise TypeError(f"Cannot add A to {other.__type__}")
+        return A(self.a + other.a)
+
+class B:
+    def __init__(self, a):
+        self.a = a 
+
+    def __add__(self, other):
+        # GOOD: Returning NotImplemented allows for other classes to support adding do B.
+        if not isinstance(other,B):
+            return NotImplemented
+        return B(self.a + other.a)
+    
+
+        

python/ql/src/Functions/examples/IncorrectRaiseInSpecialMethod2.py

@@ -0,0 +1,7 @@
+class C:
+    def __getitem__(self, idx):
+        if self.idx < 0:
+            # BAD: Should raise a KeyError or IndexError instead.
+            raise ValueError("Invalid index")
+        return self.lookup(idx)
+ 

python/ql/src/Functions/examples/IncorrectRaiseInSpecialMethod3.py

@@ -0,0 +1,4 @@
+class D:
+    def __hash__(self):
+        # BAD: Use `__hash__ = None` instead.
+        raise NotImplementedError(f"{self.__type__} is unhashable.")