refactor: *_horizontal dependent on reduce_expr to expression architecture

crates/polars-ops/Cargo.toml

@@ -90,6 +90,7 @@ string_from_radix = ["polars-core/strings"]
 extract_jsonpath = ["serde_json", "jsonpath_lib", "polars-json"]
 log = []
 hash = []
+zip_with = ["polars-core/zip_with"]
 group_by_list = ["polars-core/group_by_list"]
 rolling_window = ["polars-core/rolling_window"]
 moment = ["polars-core/moment"]

crates/polars-ops/src/series/ops/horizontal.rs

@@ -66,3 +66,15 @@ pub fn all_horizontal(s: &[Series]) -> PolarsResult<Series> {
         .with_name("all");
     Ok(out.into_series())
 }
+
+#[cfg(feature = "zip_with")]
+pub fn max_horizontal(s: &[Series]) -> PolarsResult<Option<Series>> {
+    let df = DataFrame::new_no_checks(Vec::from(s));
+    df.hmax().map(|opt_s| opt_s.map(|s| s.with_name("max")))
+}
+
+#[cfg(feature = "zip_with")]
+pub fn min_horizontal(s: &[Series]) -> PolarsResult<Option<Series>> {
+    let df = DataFrame::new_no_checks(Vec::from(s));
+    df.hmin().map(|opt_s| opt_s.map(|s| s.with_name("min")))
+}

crates/polars-plan/Cargo.toml

@@ -17,7 +17,7 @@ polars-arrow = { workspace = true }
 polars-core = { workspace = true, features = ["lazy", "zip_with", "random"], default-features = false }
 polars-ffi = { workspace = true, optional = true }
 polars-io = { workspace = true, features = ["lazy"], default-features = false }
-polars-ops = { workspace = true, default-features = false }
+polars-ops = { workspace = true, features = ["zip_with"], default-features = false }
 polars-time = { workspace = true, optional = true }
 polars-utils = { workspace = true }
 

crates/polars-plan/src/dsl/function_expr/dispatch.rs

@@ -63,3 +63,11 @@ pub(super) fn forward_fill(s: &Series, limit: FillNullLimit) -> PolarsResult<Ser
 pub(super) fn sum_horizontal(s: &[Series]) -> PolarsResult<Series> {
     polars_ops::prelude::sum_horizontal(s)
 }
+
+pub(super) fn max_horizontal(s: &mut [Series]) -> PolarsResult<Option<Series>> {
+    polars_ops::prelude::max_horizontal(s)
+}
+
+pub(super) fn min_horizontal(s: &mut [Series]) -> PolarsResult<Option<Series>> {
+    polars_ops::prelude::min_horizontal(s)
+}

crates/polars-plan/src/dsl/function_expr/mod.rs

@@ -257,6 +257,8 @@ pub enum FunctionExpr {
         limit: FillNullLimit,
     },
     SumHorizontal,
+    MaxHorizontal,
+    MinHorizontal,
 }
 
 impl Hash for FunctionExpr {
@@ -429,6 +431,8 @@ impl Display for FunctionExpr {
             BackwardFill { .. } => "backward_fill",
             ForwardFill { .. } => "forward_fill",
             SumHorizontal => "sum_horizontal",
+            MaxHorizontal => "max_horizontal",
+            MinHorizontal => "min_horizontal",
         };
         write!(f, "{s}")
     }
@@ -749,6 +753,8 @@ impl From<FunctionExpr> for SpecialEq<Arc<dyn SeriesUdf>> {
             BackwardFill { limit } => map!(dispatch::backward_fill, limit),
             ForwardFill { limit } => map!(dispatch::forward_fill, limit),
             SumHorizontal => map_as_slice!(dispatch::sum_horizontal),
+            MaxHorizontal => wrap!(dispatch::max_horizontal),
+            MinHorizontal => wrap!(dispatch::min_horizontal),
         }
     }
 }

crates/polars-plan/src/dsl/function_expr/schema.rs

@@ -237,6 +237,8 @@ impl FunctionExpr {
             BackwardFill { .. } => mapper.with_same_dtype(),
             ForwardFill { .. } => mapper.with_same_dtype(),
             SumHorizontal => mapper.map_to_supertype(),
+            MaxHorizontal => mapper.map_to_supertype(),
+            MinHorizontal => mapper.map_to_supertype(),
         }
     }
 }

crates/polars-plan/src/dsl/functions/horizontal.rs

@@ -236,11 +236,18 @@ pub fn max_horizontal<E: AsRef<[Expr]>>(exprs: E) -> Expr {
     if exprs.is_empty() {
         return Expr::Columns(Vec::new());
     }
-    let func = |s1, s2| {
-        let df = DataFrame::new_no_checks(vec![s1, s2]);
-        df.hmax()
-    };
-    reduce_exprs(func, exprs).alias("max")
+
+    Expr::Function {
+        input: exprs,
+        function: FunctionExpr::MaxHorizontal,
+        options: FunctionOptions {
+            collect_groups: ApplyOptions::ApplyFlat,
+            input_wildcard_expansion: true,
+            auto_explode: true,
+            allow_rename: true,
+            ..Default::default()
+        },
+    }
 }
 
 /// Create a new column with the the minimum value per row.
@@ -251,11 +258,18 @@ pub fn min_horizontal<E: AsRef<[Expr]>>(exprs: E) -> Expr {
     if exprs.is_empty() {
         return Expr::Columns(Vec::new());
     }
-    let func = |s1, s2| {
-        let df = DataFrame::new_no_checks(vec![s1, s2]);
-        df.hmin()
-    };
-    reduce_exprs(func, exprs).alias("min")
+
+    Expr::Function {
+        input: exprs,
+        function: FunctionExpr::MinHorizontal,
+        options: FunctionOptions {
+            collect_groups: ApplyOptions::ApplyFlat,
+            input_wildcard_expansion: true,
+            auto_explode: true,
+            allow_rename: true,
+            ..Default::default()
+        },
+    }
 }
 
 /// Create a new column with the the sum of the values in each row.

crates/polars/Cargo.toml

@@ -112,7 +112,7 @@ sort_multiple = ["polars-core/sort_multiple"]
 # extra operations
 approx_unique = ["polars-lazy?/approx_unique", "polars-ops/approx_unique"]
 is_in = ["polars-lazy?/is_in"]
-zip_with = ["polars-core/zip_with"]
+zip_with = ["polars-core/zip_with", "polars-ops/zip_with"]
 round_series = ["polars-core/round_series", "polars-lazy?/round_series", "polars-ops/round_series"]
 checked_arithmetic = ["polars-core/checked_arithmetic"]
 repeat_by = ["polars-ops/repeat_by", "polars-lazy?/repeat_by"]