perf[rust]: set sorted flag on series filled with constant (#4459)

polars/polars-core/src/chunked_array/ops/full.rs

@@ -3,14 +3,17 @@ use polars_arrow::array::default_arrays::FromData;
 
 use crate::chunked_array::builder::get_list_builder;
 use crate::prelude::*;
+use crate::series::IsSorted;
 
 impl<T> ChunkFull<T::Native> for ChunkedArray<T>
 where
     T: PolarsNumericType,
 {
     fn full(name: &str, value: T::Native, length: usize) -> Self {
         let data = vec![value; length];
-        ChunkedArray::from_vec(name, data)
+        let mut out = ChunkedArray::from_vec(name, data);
+        out.set_sorted2(IsSorted::Ascending);
+        out
     }
 }
 
@@ -27,7 +30,10 @@ impl ChunkFull<bool> for BooleanChunked {
     fn full(name: &str, value: bool, length: usize) -> Self {
         let mut bits = MutableBitmap::with_capacity(length);
         bits.extend_constant(length, value);
-        (name, BooleanArray::from_data_default(bits.into(), None)).into()
+        let mut out: BooleanChunked =
+            (name, BooleanArray::from_data_default(bits.into(), None)).into();
+        out.set_sorted2(IsSorted::Ascending);
+        out
     }
 }
 
@@ -45,7 +51,9 @@ impl<'a> ChunkFull<&'a str> for Utf8Chunked {
         for _ in 0..length {
             builder.append_value(value);
         }
-        builder.finish()
+        let mut out = builder.finish();
+        out.set_sorted2(IsSorted::Ascending);
+        out
     }
 }