remove special aggregate implementation for binary expressions

polars/polars-lazy/Cargo.toml

@@ -86,6 +86,7 @@ test = [
   "abs",
   "parquet",
   "ipc",
+  "dtype-date",
 ]
 
 [dependencies]

polars/polars-lazy/src/dsl/mod.rs

@@ -639,12 +639,12 @@ impl Expr {
 
     /// Drop null values
     pub fn drop_nulls(self) -> Self {
-        self.map(|s| Ok(s.drop_nulls()), GetOutput::same_type())
+        self.apply(|s| Ok(s.drop_nulls()), GetOutput::same_type())
     }
 
     /// Drop NaN values
     pub fn drop_nans(self) -> Self {
-        self.map(
+        self.apply(
             |s| match s.dtype() {
                 DataType::Float32 => {
                     let ca = s.f32()?;

polars/polars-lazy/src/physical_plan/expressions/binary.rs

@@ -288,29 +288,9 @@ impl PhysicalAggregation for BinaryExpr {
         groups: &GroupsProxy,
         state: &ExecutionState,
     ) -> Result<Option<Series>> {
-        match (self.left.as_agg_expr(), self.right.as_agg_expr()) {
-            (Ok(left), Ok(right)) => {
-                let (left_agg, right_agg) = POOL.install(|| {
-                    rayon::join(
-                        || left.aggregate(df, groups, state),
-                        || right.aggregate(df, groups, state),
-                    )
-                });
-                let right_agg = right_agg?;
-                left_agg?
-                    .and_then(|left| right_agg.map(|right| apply_operator(&left, &right, self.op)))
-                    .transpose()
-            }
-            (_, _) => Err(PolarsError::ComputeError(
-                format!(
-                    "this binary expression is not an aggregation: {:?}
-                pherhaps you should add an aggregation like, '.sum()', '.min()', '.mean()', etc.
-                if you really want to collect this binary expression, use `.list()`",
-                    self.expr
-                )
-                .into(),
-            )),
-        }
+        let mut ac = self.evaluate_on_groups(df, groups, state)?;
+        let s = ac.aggregated();
+        Ok(Some(s))
     }
 }
 

polars/tests/it/lazy/expressions/arity.rs

@@ -0,0 +1,17 @@
+use super::*;
+
+#[test]
+#[cfg(feature = "unique_counts")]
+fn test_list_broadcast() {
+    // simply test if this runs
+    df![
+        "g" => [1, 1, 1],
+        "a" => [1, 2, 3],
+    ]
+    .unwrap()
+    .lazy()
+    .groupby([col("g")])
+    .agg([col("a").unique_counts() * count()])
+    .collect()
+    .unwrap();
+}

polars/tests/it/lazy/expressions/mod.rs

@@ -1,3 +1,4 @@
+mod arity;
 mod is_in;
 mod slice;
 mod window;