Add MathPlugin to examples and update Conversation class in models.py

examples/math_plugin.py

@@ -0,0 +1,26 @@
+from _context import sm
+
+
+class MathPlugin:
+    def send_hook(self, conversation: sm.Conversation):
+        last_user_message = conversation.get_last_message(role="user")
+        if "calculate" in last_user_message.text.lower():
+            expression = last_user_message.text.lower().replace("calculate", "").strip()
+            try:
+                result = eval(expression)
+                conversation.add_message(
+                    role="assistant", text=f"The result is {result}."
+                )
+            except Exception:
+                conversation.add_message(
+                    role="assistant",
+                    text="I'm sorry, I couldn't compute that expression.",
+                )
+
+
+conversation = sm.create_conversation(llm_model="gpt-4o", llm_provider="openai")
+conversation.add_plugin(MathPlugin())
+
+conversation.add_message("user", "Calculate 2 + 2 * 3")
+
+print(conversation.send())

simplemind/models.py

@@ -81,6 +81,10 @@ class Conversation(SMBaseModel):
         self.add_message(role="assistant", text=response.text, meta=response.meta)
         return response
 
+    def get_last_message(self, role: MESSAGE_ROLE) -> Optional[Message]:
+        """Get the last message with the given role."""
+        return next((m for m in reversed(self.messages) if m.role == role), None)
+
     def add_plugin(self, plugin: Any):
         """Add a plugin to the conversation."""
         self.plugins.append(plugin)