adriangb commented on code in PR #19433:
URL: https://github.com/apache/datafusion/pull/19433#discussion_r2673507448
##########
datafusion/physical-expr-common/src/sort_expr.rs:
##########
@@ -803,6 +818,130 @@ impl DerefMut for OrderingRequirements {
#[cfg(test)]
mod tests {
use super::*;
+ use arrow::datatypes::{DataType, FieldRef, Schema};
+ use arrow::record_batch::RecordBatch;
+ use datafusion_common::Result;
+ use datafusion_expr_common::columnar_value::ColumnarValue;
+ use std::any::Any;
+ use std::fmt::{Display, Formatter};
+
+ /// A simple mock PhysicalExpr for testing, identified by name.
+ #[derive(Debug, Clone, PartialEq, Eq, Hash)]
+ struct TestExpr {
+ name: &'static str,
+ }
+
+ impl TestExpr {
+ fn new_expr(name: &'static str) -> Arc<dyn PhysicalExpr> {
+ Arc::new(Self { name })
+ }
+ }
+
+ impl Display for TestExpr {
+ fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
+ write!(f, "{}", self.name)
+ }
+ }
+
+ impl PhysicalExpr for TestExpr {
+ fn as_any(&self) -> &dyn Any {
+ self
+ }
+
+ fn data_type(&self, _input_schema: &Schema) -> Result<DataType> {
+ Ok(DataType::Int32)
+ }
+
+ fn nullable(&self, _input_schema: &Schema) -> Result<bool> {
+ Ok(true)
+ }
+
+ fn evaluate(&self, _batch: &RecordBatch) -> Result<ColumnarValue> {
+ unimplemented!("TestExpr::evaluate is not needed for sort tests")
+ }
+
+ fn children(&self) -> Vec<&Arc<dyn PhysicalExpr>> {
+ vec![]
+ }
+
+ fn with_new_children(
+ self: Arc<Self>,
+ _children: Vec<Arc<dyn PhysicalExpr>>,
+ ) -> Result<Arc<dyn PhysicalExpr>> {
+ Ok(self)
+ }
+
+ fn fmt_sql(&self, f: &mut Formatter<'_>) -> fmt::Result {
+ write!(f, "{}", self.name)
+ }
+
+ fn return_field(&self, _input_schema: &Schema) -> Result<FieldRef> {
+ unimplemented!("TestExpr::return_field is not needed for sort
tests")
+ }
+ }
+
+ /// Helper to create a PhysicalSortExpr with the given expression and
options.
+ fn sort_expr(expr: Arc<dyn PhysicalExpr>, options: SortOptions) ->
PhysicalSortExpr {
+ PhysicalSortExpr::new(expr, options)
+ }
+
+ #[test]
+ fn test_is_prefix() {
+ let asc = SortOptions {
+ descending: false,
+ nulls_first: false,
+ };
+ let desc = SortOptions {
+ descending: true,
+ nulls_first: true,
+ };
+
+ let a = TestExpr::new_expr("a");
+ let b = TestExpr::new_expr("b");
+ let c = TestExpr::new_expr("c");
+
+ // [a ASC] is a prefix of [a ASC] (exact match)
+ let ordering1 = LexOrdering::new([sort_expr(Arc::clone(&a),
asc)]).unwrap();
+ let ordering2 = LexOrdering::new([sort_expr(Arc::clone(&a),
asc)]).unwrap();
+ assert!(ordering1.is_prefix(&ordering2));
+
+ // [a ASC] is a prefix of [a ASC, b DESC]
+ let ordering_ab = LexOrdering::new([
+ sort_expr(Arc::clone(&a), asc),
+ sort_expr(Arc::clone(&b), desc),
+ ])
+ .unwrap();
+ assert!(ordering_ab.is_prefix(&ordering1));
+
+ // [a ASC, b DESC] is NOT a prefix of [a ASC] (other is longer)
+ assert!(!ordering1.is_prefix(&ordering_ab));
+
+ // [a DESC] is NOT a prefix of [a ASC] (different sort options)
+ let ordering_a_desc =
+ LexOrdering::new([sort_expr(Arc::clone(&a), desc)]).unwrap();
+ assert!(!ordering1.is_prefix(&ordering_a_desc));
+
+ // [b ASC] is NOT a prefix of [a ASC] (different expressions)
+ let ordering_b = LexOrdering::new([sort_expr(Arc::clone(&b),
asc)]).unwrap();
+ assert!(!ordering1.is_prefix(&ordering_b));
+
+ // [a ASC, b ASC] is a prefix of [a ASC, b ASC, c ASC]
+ let ordering_ab_asc = LexOrdering::new([
+ sort_expr(Arc::clone(&a), asc),
+ sort_expr(Arc::clone(&b), asc),
+ ])
+ .unwrap();
+ let ordering_abc = LexOrdering::new([
+ sort_expr(Arc::clone(&a), asc),
+ sort_expr(Arc::clone(&b), asc),
+ sort_expr(Arc::clone(&c), asc),
+ ])
+ .unwrap();
+ assert!(ordering_abc.is_prefix(&ordering_ab_asc));
+
+ // [a ASC, b DESC] is NOT a prefix of [a ASC, b ASC, c ASC] (mismatch
in middle)
+ assert!(!ordering_abc.is_prefix(&ordering_ab));
+ }
Review Comment:
added in 25a5aa044
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
To unsubscribe, e-mail: [email protected]
For queries about this service, please contact Infrastructure at:
[email protected]
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
