multiple: langchain 0.2 in master (#21191)

0.2rc 

migrations

- [x] Move memory
- [x] Move remaining retrievers
- [x] graph_qa chains
- [x] some dependency from evaluation code potentially on math utils
- [x] Move openapi chain from `langchain.chains.api.openapi` to
`langchain_community.chains.openapi`
- [x] Migrate `langchain.chains.ernie_functions` to
`langchain_community.chains.ernie_functions`
- [x] migrate `langchain/chains/llm_requests.py` to
`langchain_community.chains.llm_requests`
- [x] Moving `langchain_community.cross_enoders.base:BaseCrossEncoder`
->
`langchain_community.retrievers.document_compressors.cross_encoder:BaseCrossEncoder`
(namespace not ideal, but it needs to be moved to `langchain` to avoid
circular deps)
- [x] unit tests langchain -- add pytest.mark.community to some unit
tests that will stay in langchain
- [x] unit tests community -- move unit tests that depend on community
to community
- [x] mv integration tests that depend on community to community
- [x] mypy checks

Other todo

- [x] Make deprecation warnings not noisy (need to use warn deprecated
and check that things are implemented properly)
- [x] Update deprecation messages with timeline for code removal (likely
we actually won't be removing things until 0.4 release) -- will give
people more time to transition their code.
- [ ] Add information to deprecation warning to show users how to
migrate their code base using langchain-cli
- [ ] Remove any unnecessary requirements in langchain (e.g., is
SQLALchemy required?)

---------

Co-authored-by: Erick Friis <erick@langchain.dev>

libs/community/langchain_community/query_constructors/dingo.py

@@ -0,0 +1,49 @@
+from typing import Tuple, Union
+
+from langchain_core.structured_query import (
+    Comparator,
+    Comparison,
+    Operation,
+    Operator,
+    StructuredQuery,
+    Visitor,
+)
+
+
+class DingoDBTranslator(Visitor):
+    """Translate `DingoDB` internal query language elements to valid filters."""
+
+    allowed_comparators = (
+        Comparator.EQ,
+        Comparator.NE,
+        Comparator.LT,
+        Comparator.LTE,
+        Comparator.GT,
+        Comparator.GTE,
+    )
+    """Subset of allowed logical comparators."""
+    allowed_operators = (Operator.AND, Operator.OR)
+    """Subset of allowed logical operators."""
+
+    def _format_func(self, func: Union[Operator, Comparator]) -> str:
+        self._validate_func(func)
+        return f"${func.value}"
+
+    def visit_operation(self, operation: Operation) -> Operation:
+        return operation
+
+    def visit_comparison(self, comparison: Comparison) -> Comparison:
+        return comparison
+
+    def visit_structured_query(
+        self, structured_query: StructuredQuery
+    ) -> Tuple[str, dict]:
+        if structured_query.filter is None:
+            kwargs = {}
+        else:
+            kwargs = {
+                "search_params": {
+                    "langchain_expr": structured_query.filter.accept(self)
+                }
+            }
+        return structured_query.query, kwargs