docs: Fix some warnings during doc build

docs/_build/API_REFERENCE_LINKS.yml

@@ -1,7 +1,8 @@
 python:
   DataFrame: https://docs.pola.rs/api/python/stable/reference/dataframe/index.html
-  Categorical: https://docs.pola.rs/api/python/stable/reference/api/polars.Categorical.html
+  LazyFrame: https://docs.pola.rs/api/python/stable/reference/lazyframe/index.html
   Series: https://docs.pola.rs/api/python/stable/reference/series/index.html
+  Categorical: https://docs.pola.rs/api/python/stable/reference/api/polars.Categorical.html
   select: https://docs.pola.rs/api/python/stable/reference/dataframe/api/polars.DataFrame.select.html
   filter: https://docs.pola.rs/api/python/stable/reference/dataframe/api/polars.DataFrame.filter.html
   with_columns: https://docs.pola.rs/api/python/stable/reference/dataframe/api/polars.DataFrame.with_columns.html
@@ -151,6 +152,7 @@ python:
 
 rust:
   DataFrame: https://docs.pola.rs/api/rust/dev/polars/frame/struct.DataFrame.html
+  LazyFrame: https://docs.pola.rs/api/rust/dev/polars/prelude/struct.LazyFrame.html
   Series: https://docs.pola.rs/api/rust/dev/polars/series/struct.Series.html
   Categorical:
     name: Categorical

docs/src/python/user-guide/expressions/user-defined-functions.py

@@ -46,16 +46,18 @@ def add_counter(val: int) -> int:
 
 
 out = df.select(
-    pl.col("values").map_elements(add_counter).alias("solution_map_elements"),
+    pl.col("values")
+    .map_elements(add_counter, return_dtype=pl.Int64)
+    .alias("solution_map_elements"),
     (pl.col("values") + pl.int_range(1, pl.len() + 1)).alias("solution_expr"),
 )
 print(out)
 # --8<-- [end:counter]
 
 # --8<-- [start:combine]
 out = df.select(
-    pl.struct(["keys", "values"])
-    .map_elements(lambda x: len(x["keys"]) + x["values"])
+    pl.struct("keys", "values")
+    .map_elements(lambda x: len(x["keys"]) + x["values"], return_dtype=pl.Int64)
     .alias("solution_map_elements"),
     (pl.col("keys").str.len_bytes() + pl.col("values")).alias("solution_expr"),
 )

py-polars/polars/lazyframe/frame.py

@@ -1041,6 +1041,9 @@ def explain(
             if tree_format:
                 format = "tree"
 
+        if streaming:
+            issue_unstable_warning("Streaming mode is considered unstable.")
+
         if optimized:
             ldf = self._ldf.optimization_toggle(
                 type_coercion,
@@ -1872,7 +1875,6 @@ def collect(
 
         if streaming:
             issue_unstable_warning("Streaming mode is considered unstable.")
-            comm_subplan_elim = False
 
         ldf = self._ldf.optimization_toggle(
             type_coercion,
@@ -2048,7 +2050,6 @@ def collect_async(
 
         if streaming:
             issue_unstable_warning("Streaming mode is considered unstable.")
-            comm_subplan_elim = False
 
         ldf = self._ldf.optimization_toggle(
             type_coercion,
@@ -2622,6 +2623,9 @@ def fetch(
             comm_subexpr_elim = False
             cluster_with_columns = False
 
+        if streaming:
+            issue_unstable_warning("Streaming mode is considered unstable.")
+
         lf = self._ldf.optimization_toggle(
             type_coercion,
             predicate_pushdown,

py-polars/src/lazyframe/mod.rs

@@ -489,7 +489,7 @@ impl PyLazyFrame {
         projection_pushdown: bool,
         simplify_expr: bool,
         slice_pushdown: bool,
-        comm_subplan_elim: bool,
+        mut comm_subplan_elim: bool,
         comm_subexpr_elim: bool,
         cluster_with_columns: bool,
         streaming: bool,
@@ -512,6 +512,9 @@ impl PyLazyFrame {
             ldf = ldf.with_new_streaming(new_streaming);
         }
 
+        if streaming {
+            comm_subplan_elim = false;
+        }
         #[cfg(feature = "cse")]
         {
             ldf = ldf.with_comm_subplan_elim(comm_subplan_elim);