text streaming ability added to OpenAI provider

simplemind/providers/openai.py

@@ -106,3 +106,23 @@ class OpenAI(BaseProvider):
             **{**self.DEFAULT_KWARGS, **kwargs},
         )
         return response.choices[0].message.content
+    
+    @logger
+    def generate_stream_text(self, prompt: str, *, llm_model: str | None = None, **kwargs):
+        """Generate streaming text using the OpenAI API.
+        
+        Yields chunks of text as they are generated by the model.
+        """
+        messages = [
+            {"role": "user", "content": prompt},
+        ]
+        response = self.client.chat.completions.create(
+            messages=messages,
+            model=llm_model or self.DEFAULT_MODEL,
+            stream=True,  # Enable streaming
+            **{**self.DEFAULT_KWARGS, **kwargs},
+        )
+        
+        for chunk in response:
+            if chunk.choices[0].delta.content is not None:
+                yield chunk.choices[0].delta.content