feat: add experimental decorator

ibis/backends/base/__init__.py

@@ -231,6 +231,7 @@ def _table_or_column_schema(expr: ir.Expr) -> sch.Schema:
             # ColumnExpr has no schema method, define single-column schema
             return sch.schema([(expr.get_name(), expr.type())])
 
+    @util.experimental
     def to_pyarrow(
         self,
         expr: ir.Expr,
@@ -239,6 +240,26 @@ def to_pyarrow(
         limit: int | str | None = None,
         **kwargs: Any,
     ) -> pa.Table:
+        """Execute expression and return results in as a pyarrow table.
+
+        This method is eager and will execute the associated expression
+        immediately.
+
+        Parameters
+        ----------
+        expr
+            Ibis expression to export to pyarrow
+        params
+            Mapping of scalar parameter expressions to value.
+        limit
+            An integer to effect a specific row limit. A value of `None` means
+            "no limit". The default is in `ibis/config.py`.
+
+        Returns
+        -------
+        Table
+            A pyarrow table holding the results of the executed expression.
+        """
         pa = self._import_pyarrow()
         try:
             # Can't construct an array from record batches
@@ -269,6 +290,7 @@ def to_pyarrow(
         else:
             raise ValueError
 
+    @util.experimental
     def to_pyarrow_batches(
         self,
         expr: ir.Expr,
@@ -278,6 +300,29 @@ def to_pyarrow_batches(
         chunk_size: int = 1_000_000,
         **kwargs: Any,
     ) -> pa.RecordBatchReader:
+        """Execute expression and return results in an iterator of pyarrow
+        record batches.
+
+        This method is eager and will execute the associated expression
+        immediately.
+
+        Parameters
+        ----------
+        expr
+            Ibis expression to export to pyarrow
+        limit
+            An integer to effect a specific row limit. A value of `None` means
+            "no limit". The default is in `ibis/config.py`.
+        params
+            Mapping of scalar parameter expressions to value.
+        chunk_size
+            Number of rows in each returned record batch.
+
+        Returns
+        -------
+        record_batches
+            An iterator of pyarrow record batches.
+        """
         raise NotImplementedError
 
 

ibis/backends/base/sql/__init__.py

@@ -158,6 +158,7 @@ def _cursor_batches(
             while batch := cursor.fetchmany(chunk_size):
                 yield batch
 
+    @util.experimental
     def to_pyarrow_batches(
         self,
         expr: ir.Expr,
@@ -167,6 +168,29 @@ def to_pyarrow_batches(
         chunk_size: int = 1_000_000,
         **kwargs: Any,
     ) -> pa.RecordBatchReader:
+        """Execute expression and return results in an iterator of pyarrow
+        record batches.
+
+        This method is eager and will execute the associated expression
+        immediately.
+
+        Parameters
+        ----------
+        expr
+            Ibis expression to export to pyarrow
+        limit
+            An integer to effect a specific row limit. A value of `None` means
+            "no limit". The default is in `ibis/config.py`.
+        params
+            Mapping of scalar parameter expressions to value.
+        chunk_size
+            Number of rows in each returned record batch.
+
+        Returns
+        -------
+        record_batches
+            An iterator of pyarrow record batches.
+        """
         pa = self._import_pyarrow()
 
         from ibis.backends.pyarrow.datatypes import ibis_to_pyarrow_struct

ibis/expr/types/core.py

@@ -13,7 +13,7 @@
 from ibis.common.grounds import Immutable
 from ibis.config import _default_backend, options
 from ibis.expr.typing import TimeContext
-from ibis.util import UnnamedMarker
+from ibis.util import UnnamedMarker, experimental
 
 if TYPE_CHECKING:
     import pyarrow as pa
@@ -308,6 +308,7 @@ def compile(
             self, limit=limit, timecontext=timecontext, params=params
         )
 
+    @experimental
     def to_pyarrow_batches(
         self,
         *,
@@ -319,8 +320,8 @@ def to_pyarrow_batches(
         """Execute expression and return results in an iterator of pyarrow
         record batches.
 
-        **Warning**: This method is eager and will execute the associated
-        expression immediately. This API is experimental and subject to change.
+        This method is eager and will execute the associated expression
+        immediately.
 
         Parameters
         ----------
@@ -345,6 +346,7 @@ def to_pyarrow_batches(
             **kwargs,
         )
 
+    @experimental
     def to_pyarrow(
         self,
         *,
@@ -354,17 +356,16 @@ def to_pyarrow(
     ) -> pa.Table:
         """Execute expression and return results in as a pyarrow table.
 
-        **Warning**: This method is eager and will execute the associated
-        expression immediately. This API is experimental and subject to change.
-
+        This method is eager and will execute the associated expression
+        immediately.
 
         Parameters
         ----------
+        params
+            Mapping of scalar parameter expressions to value.
         limit
             An integer to effect a specific row limit. A value of `None` means
             "no limit". The default is in `ibis/config.py`.
-        params
-            Mapping of scalar parameter expressions to value.
 
         Returns
         -------

ibis/util.py

@@ -448,6 +448,34 @@ def wrapper(*args, **kwargs):
     return decorator
 
 
+def experimental(func):
+    """Decorate experimental function to add warning about potential API
+    instability in docstring."""
+
+    msg = "This API is experimental and subject to change."
+
+    if docstr := func.__doc__:
+        preamble, *rest = docstr.split("\n\n", maxsplit=1)
+
+        leading_spaces = " " * sum(
+            1
+            for _ in itertools.takewhile(str.isspace, rest[0] if rest else [])
+        )
+
+        warning_doc = f'{leading_spaces}!!! warning "{msg}"'
+
+        docstr = "\n\n".join([preamble, warning_doc, *rest])
+    else:
+        docstr = f'!!! warning "{msg}"'
+    func.__doc__ = docstr
+
+    @functools.wraps(func)
+    def wrapper(*args, **kwargs):
+        return func(*args, **kwargs)
+
+    return wrapper
+
+
 class ToFrame(abc.ABC):
     """Interface for in-memory objects that can be converted to a DataFrame."""