chore: import upstream snapshot with attribution

python/semantic_kernel/contents/streaming_text_content.py

@@ -0,0 +1,55 @@
+# Copyright (c) Microsoft. All rights reserved.
+
+from semantic_kernel.contents.streaming_content_mixin import StreamingContentMixin
+from semantic_kernel.contents.text_content import TextContent
+from semantic_kernel.exceptions import ContentAdditionException
+
+
+class StreamingTextContent(StreamingContentMixin, TextContent):
+    """This represents streaming text response content.
+
+    Args:
+        choice_index: int - The index of the choice that generated this response.
+        inner_content: Optional[Any] - The inner content of the response,
+            this should hold all the information from the response so even
+            when not creating a subclass a developer can leverage the full thing.
+        ai_model_id: Optional[str] - The id of the AI model that generated this response.
+        metadata: Dict[str, Any] - Any metadata that should be attached to the response.
+        text: Optional[str] - The text of the response.
+        encoding: Optional[str] - The encoding of the text.
+
+    Methods:
+        __str__: Returns the text of the response.
+        __bytes__: Returns the content of the response encoded in the encoding.
+        __add__: Combines two StreamingTextContent instances.
+    """
+
+    def __bytes__(self) -> bytes:
+        """Return the content of the response encoded in the encoding."""
+        return self.text.encode(self.encoding if self.encoding else "utf-8") if self.text else b""
+
+    def __add__(self, other: TextContent) -> "StreamingTextContent":
+        """When combining two StreamingTextContent instances, the text fields are combined.
+
+        The addition should follow these rules:
+            1. The inner_content of the two will be combined. If they are not lists, they will be converted to lists.
+            2. ai_model_id should be the same.
+            3. encoding should be the same.
+            4. choice_index should be the same.
+            5. Metadata will be combined.
+        """
+        if isinstance(other, StreamingTextContent) and self.choice_index != other.choice_index:
+            raise ContentAdditionException("Cannot add StreamingTextContent with different choice_index")
+        if self.ai_model_id != other.ai_model_id:
+            raise ContentAdditionException("Cannot add StreamingTextContent from different ai_model_id")
+        if self.encoding != other.encoding:
+            raise ContentAdditionException("Cannot add StreamingTextContent with different encoding")
+
+        return StreamingTextContent(
+            choice_index=self.choice_index,
+            inner_content=self._merge_inner_contents(other.inner_content),
+            ai_model_id=self.ai_model_id,
+            metadata=self.metadata,
+            text=(self.text or "") + (other.text or ""),
+            encoding=self.encoding,
+        )