fix

docs/docs/expression_language/how_to/generators.ipynb

@@ -123,7 +123,9 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "list_chain = str_chain | split_into_list"
+    "from langchain_core.runnables import RunnableGenerator\n",
+    "\n",
+    "list_chain = str_chain | RunnableGenerator(split_into_list)"
    ]
   },
   {
@@ -199,7 +201,7 @@
     "    yield [buffer.strip()]\n",
     "\n",
     "\n",
-    "list_chain = str_chain | asplit_into_list"
+    "list_chain = str_chain | RunnableGenerator(asplit_into_list)"
    ]
   },
   {

docs/docs/expression_language/streaming.ipynb

@@ -360,6 +360,7 @@
    ],
    "source": [
     "from langchain_core.output_parsers import JsonOutputParser\n",
+    "from langchain_core.runnables import RunnableGenerator\n",
     "\n",
     "\n",
     "async def _extract_country_names_streaming(input_stream):\n",
@@ -387,7 +388,7 @@
     "                country_names_so_far.add(name)\n",
     "\n",
     "\n",
-    "chain = model | JsonOutputParser() | _extract_country_names_streaming\n",
+    "chain = model | JsonOutputParser() | RunnableGenerator(_extract_country_names_streaming)\n",
     "\n",
     "async for text in chain.astream(\n",
     "    'output a list of the countries france, spain and japan and their populations in JSON format. Use a dict with an outer key of \"countries\" which contains a list of countries. Each country should have the key `name` and `population`'\n",
@@ -1383,7 +1384,7 @@
  ],
  "metadata": {
   "kernelspec": {
-   "display_name": "Python 3 (ipykernel)",
+   "display_name": ".docs-venv",
    "language": "python",
    "name": "python3"
   },

docs/docs/modules/model_io/output_parsers/types/xml.ipynb

@@ -155,31 +155,10 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 7,
+   "execution_count": null,
    "id": "808a5df5-b11e-42a0-bd7a-6b95ca0c3eba",
    "metadata": {},
-   "outputs": [
-    {
-     "ename": "ParseError",
-     "evalue": "syntax error: line 1, column 1 (<string>)",
-     "output_type": "error",
-     "traceback": [
-      "Traceback \u001b[0;36m(most recent call last)\u001b[0m:\n",
-      "\u001b[0m  File \u001b[1;32m~/.pyenv/versions/3.10.1/envs/langchain/lib/python3.10/site-packages/IPython/core/interactiveshell.py:3508\u001b[0m in \u001b[1;35mrun_code\u001b[0m\n    exec(code_obj, self.user_global_ns, self.user_ns)\u001b[0m\n",
-      "\u001b[0m  Cell \u001b[1;32mIn[7], line 1\u001b[0m\n    for s in chain.stream({\"query\": actor_query}):\u001b[0m\n",
-      "\u001b[0m  File \u001b[1;32m~/workplace/langchain/libs/core/langchain_core/runnables/base.py:1984\u001b[0m in \u001b[1;35mstream\u001b[0m\n    yield from self.transform(iter([input]), config, **kwargs)\u001b[0m\n",
-      "\u001b[0m  File \u001b[1;32m~/workplace/langchain/libs/core/langchain_core/runnables/base.py:1974\u001b[0m in \u001b[1;35mtransform\u001b[0m\n    yield from self._transform_stream_with_config(\u001b[0m\n",
-      "\u001b[0m  File \u001b[1;32m~/workplace/langchain/libs/core/langchain_core/runnables/base.py:1141\u001b[0m in \u001b[1;35m_transform_stream_with_config\u001b[0m\n    for chunk in iterator:\u001b[0m\n",
-      "\u001b[0m  File \u001b[1;32m~/workplace/langchain/libs/core/langchain_core/runnables/base.py:1938\u001b[0m in \u001b[1;35m_transform\u001b[0m\n    for output in final_pipeline:\u001b[0m\n",
-      "\u001b[0m  File \u001b[1;32m~/workplace/langchain/libs/core/langchain_core/output_parsers/transform.py:50\u001b[0m in \u001b[1;35mtransform\u001b[0m\n    yield from self._transform_stream_with_config(\u001b[0m\n",
-      "\u001b[0m  File \u001b[1;32m~/workplace/langchain/libs/core/langchain_core/runnables/base.py:1141\u001b[0m in \u001b[1;35m_transform_stream_with_config\u001b[0m\n    for chunk in iterator:\u001b[0m\n",
-      "\u001b[0m  File \u001b[1;32m~/workplace/langchain/libs/core/langchain_core/output_parsers/xml.py:71\u001b[0m in \u001b[1;35m_transform\u001b[0m\n    for event, elem in parser.read_events():\u001b[0m\n",
-      "\u001b[0m  File \u001b[1;32m~/.pyenv/versions/3.10.1/lib/python3.10/xml/etree/ElementTree.py:1329\u001b[0m in \u001b[1;35mread_events\u001b[0m\n    raise event\u001b[0m\n",
-      "\u001b[0;36m  File \u001b[0;32m~/.pyenv/versions/3.10.1/lib/python3.10/xml/etree/ElementTree.py:1301\u001b[0;36m in \u001b[0;35mfeed\u001b[0;36m\n\u001b[0;31m    self._parser.feed(data)\u001b[0;36m\n",
-      "\u001b[0;36m  File \u001b[0;32m<string>\u001b[0;36m\u001b[0m\n\u001b[0;31mParseError\u001b[0m\u001b[0;31m:\u001b[0m syntax error: line 1, column 1\n"
-     ]
-    }
-   ],
+   "outputs": [],
    "source": [
     "for s in chain.stream({\"query\": actor_query}):\n",
     "    print(s)"

libs/core/langchain_core/runnables/base.py

@@ -36,6 +36,7 @@ from typing import (
 from typing_extensions import Literal, get_args
 
 from langchain_core._api import beta_decorator
+from langchain_core._api.deprecation import warn_deprecated
 from langchain_core.load.dump import dumpd
 from langchain_core.load.serializable import (
     Serializable,
@@ -4366,7 +4367,21 @@ def coerce_to_runnable(thing: RunnableLike) -> Runnable[Input, Output]:
     if isinstance(thing, Runnable):
         return thing
     elif inspect.isasyncgenfunction(thing) or inspect.isgeneratorfunction(thing):
-        return RunnableGenerator(thing)
+        result = RunnableGenerator(thing)
+        message = (
+            "Implicit coercion of custom functions to a "
+            "RunnableGenerator will be deprecated, and all implicit function coercion"
+            " will convert to a RunnableLambda."
+            " Please explicitly convert to a RunnableGenerator using:\n"
+            "from langchain_core.runnable import RunnableGenerator\n\n"
+            "runnable = (\n    ...\n"
+            f"    | RunnableGenerator({thing.__name__})\n"
+            ")\n"
+        )
+
+        warn_deprecated("0.1.26", message=message, removal="0.2.0")
+        return result
+
     elif callable(thing):
         return RunnableLambda(cast(Callable[[Input], Output], thing))
     elif isinstance(thing, dict):

libs/core/tests/unit_tests/runnables/test_runnable.py

@@ -22,6 +22,7 @@ from pytest_mock import MockerFixture
 from syrupy import SnapshotAssertion
 from typing_extensions import TypedDict
 
+from langchain_core._api.deprecation import LangChainDeprecationWarning
 from langchain_core.callbacks.manager import (
     Callbacks,
     atrace_as_chain_group,
@@ -69,7 +70,7 @@ from langchain_core.runnables import (
     add,
     chain,
 )
-from langchain_core.runnables.base import RunnableSerializable
+from langchain_core.runnables.base import RunnableSerializable, coerce_to_runnable
 from langchain_core.tools import BaseTool, tool
 from langchain_core.tracers import (
     BaseTracer,
@@ -5183,3 +5184,28 @@ async def test_astream_log_deep_copies() -> None:
         "name": "add_one",
         "type": "chain",
     }
+
+
+def test_coerce_to_runnable() -> None:
+    """Test that a callable can be coerced to a runnable."""
+
+    def add_one(x: int) -> int:
+        """Add one."""
+        return x + 1
+
+    runnable = coerce_to_runnable(add_one)
+    assert runnable.invoke(1) == 2
+    assert isinstance(runnable, RunnableLambda)
+
+    def some_generator(x: Any) -> Iterator[int]:
+        """Return 1."""
+        yield 1
+
+    # Assert that a warning is raised when trying to coerce a generator
+    with pytest.warns(
+        LangChainDeprecationWarning,
+    ):
+        runnable = coerce_to_runnable(some_generator)
+    assert runnable.invoke(1) == 1
+    # To change in 0.2.0
+    assert isinstance(runnable, RunnableGenerator)