feat: Show warning if expressions are very deep (#16233)

crates/polars-lazy/src/dsl/eval.rs

@@ -2,7 +2,7 @@ use polars_core::prelude::*;
 use rayon::prelude::*;
 
 use super::*;
-use crate::physical_plan::planner::create_physical_expr;
+use crate::physical_plan::planner::{create_physical_expr, ExpressionConversionState};
 use crate::physical_plan::state::ExecutionState;
 use crate::prelude::*;
 
@@ -61,7 +61,7 @@ pub trait ExprEvalExtension: IntoExpr + Sized {
                 Context::Default,
                 &arena,
                 None,
-                &mut Default::default(),
+                &mut ExpressionConversionState::new(true, 0),
             )?;
 
             let state = ExecutionState::new();

crates/polars-lazy/src/frame/mod.rs

@@ -37,7 +37,9 @@ use polars_plan::global::FETCH_ROWS;
 use smartstring::alias::String as SmartString;
 
 use crate::physical_plan::executors::Executor;
-use crate::physical_plan::planner::{create_physical_expr, create_physical_plan};
+use crate::physical_plan::planner::{
+    create_physical_expr, create_physical_plan, ExpressionConversionState,
+};
 use crate::physical_plan::state::ExecutionState;
 #[cfg(feature = "streaming")]
 use crate::physical_plan::streaming::insert_streaming_nodes;
@@ -571,7 +573,7 @@ impl LazyFrame {
                     Context::Default,
                     expr_arena,
                     None,
-                    &mut Default::default(),
+                    &mut ExpressionConversionState::new(true, 0),
                 )
                 .ok()?;
                 let io_expr = phys_expr_to_io_expr(phys_expr);

crates/polars-lazy/src/physical_plan/exotic.rs

@@ -1,6 +1,6 @@
 use polars_core::prelude::*;
 
-use crate::physical_plan::planner::create_physical_expr;
+use crate::physical_plan::planner::{create_physical_expr, ExpressionConversionState};
 use crate::prelude::*;
 
 #[cfg(feature = "pivot")]
@@ -34,5 +34,11 @@ pub(crate) fn prepare_expression_for_context(
     let lp = lp_arena.get(optimized);
     let aexpr = lp.get_exprs().pop().unwrap();
 
-    create_physical_expr(&aexpr, ctxt, &expr_arena, None, &mut Default::default())
+    create_physical_expr(
+        &aexpr,
+        ctxt,
+        &expr_arena,
+        None,
+        &mut ExpressionConversionState::new(true, 0),
+    )
 }