ext/polars/src/lazy/apply.rs in polars-df-0.1.4 vs ext/polars/src/lazy/apply.rs in polars-df-0.1.5

@@ -1,7 +1,39 @@
 use magnus::Value;
-use polars::error::PolarsResult;
-use polars::series::Series;
+use polars::prelude::*;
 
+use crate::lazy::dsl::RbExpr;
+use crate::Wrap;
+
 pub fn binary_lambda(_lambda: Value, _a: Series, _b: Series) -> PolarsResult<Series> {
     todo!();
+}
+
+pub fn map_single(
+    rbexpr: &RbExpr,
+    _lambda: Value,
+    output_type: Option<Wrap<DataType>>,
+    agg_list: bool,
+) -> RbExpr {
+    let output_type = output_type.map(|wrap| wrap.0);
+
+    let output_type2 = output_type.clone();
+    let function = move |_s: Series| {
+        let _output_type = output_type2.clone().unwrap_or(DataType::Unknown);
+
+        todo!();
+    };
+
+    let output_map = GetOutput::map_field(move |fld| match output_type {
+        Some(ref dt) => Field::new(fld.name(), dt.clone()),
+        None => {
+            let mut fld = fld.clone();
+            fld.coerce(DataType::Unknown);
+            fld
+        }
+    });
+    if agg_list {
+        rbexpr.clone().inner.map_list(function, output_map).into()
+    } else {
+        rbexpr.clone().inner.map(function, output_map).into()
+    }
 }