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/opensearch.py

@@ -0,0 +1,104 @@
+from typing import Dict, Tuple, Union
+
+from langchain_core.structured_query import (
+    Comparator,
+    Comparison,
+    Operation,
+    Operator,
+    StructuredQuery,
+    Visitor,
+)
+
+
+class OpenSearchTranslator(Visitor):
+    """Translate `OpenSearch` internal query domain-specific
+    language elements to valid filters."""
+
+    allowed_comparators = [
+        Comparator.EQ,
+        Comparator.LT,
+        Comparator.LTE,
+        Comparator.GT,
+        Comparator.GTE,
+        Comparator.CONTAIN,
+        Comparator.LIKE,
+    ]
+    """Subset of allowed logical comparators."""
+
+    allowed_operators = [Operator.AND, Operator.OR, Operator.NOT]
+    """Subset of allowed logical operators."""
+
+    def _format_func(self, func: Union[Operator, Comparator]) -> str:
+        self._validate_func(func)
+        comp_operator_map = {
+            Comparator.EQ: "term",
+            Comparator.LT: "lt",
+            Comparator.LTE: "lte",
+            Comparator.GT: "gt",
+            Comparator.GTE: "gte",
+            Comparator.CONTAIN: "match",
+            Comparator.LIKE: "fuzzy",
+            Operator.AND: "must",
+            Operator.OR: "should",
+            Operator.NOT: "must_not",
+        }
+        return comp_operator_map[func]
+
+    def visit_operation(self, operation: Operation) -> Dict:
+        args = [arg.accept(self) for arg in operation.arguments]
+
+        return {"bool": {self._format_func(operation.operator): args}}
+
+    def visit_comparison(self, comparison: Comparison) -> Dict:
+        field = f"metadata.{comparison.attribute}"
+
+        if comparison.comparator in [
+            Comparator.LT,
+            Comparator.LTE,
+            Comparator.GT,
+            Comparator.GTE,
+        ]:
+            if isinstance(comparison.value, dict):
+                if "date" in comparison.value:
+                    return {
+                        "range": {
+                            field: {
+                                self._format_func(
+                                    comparison.comparator
+                                ): comparison.value["date"]
+                            }
+                        }
+                    }
+            else:
+                return {
+                    "range": {
+                        field: {
+                            self._format_func(comparison.comparator): comparison.value
+                        }
+                    }
+                }
+
+        if comparison.comparator == Comparator.LIKE:
+            return {
+                self._format_func(comparison.comparator): {
+                    field: {"value": comparison.value}
+                }
+            }
+
+        field = f"{field}.keyword" if isinstance(comparison.value, str) else field
+
+        if isinstance(comparison.value, dict):
+            if "date" in comparison.value:
+                comparison.value = comparison.value["date"]
+
+        return {self._format_func(comparison.comparator): {field: comparison.value}}
+
+    def visit_structured_query(
+        self, structured_query: StructuredQuery
+    ) -> Tuple[str, dict]:
+        if structured_query.filter is None:
+            kwargs = {}
+        else:
+            kwargs = {"filter": structured_query.filter.accept(self)}
+
+        return structured_query.query, kwargs