expr test

Signed-off-by: Onur Satici <onur@spiraldb.com>

Author: onursatici

vortex-array/src/expression.rs

@@ -17,28 +17,32 @@ use crate::scalar_fn::fns::root::Root;
 impl dyn DynArray + '_ {
     /// Apply the expression to this array, producing a new array in constant time.
     pub fn apply(&self, expr: &Expression) -> VortexResult<ArrayRef> {
-        // If the expression is a root, return self.
-        if expr.is::<Root>() {
-            return Ok(self.to_array());
-        }
-
-        // Manually convert literals to ConstantArray.
-        if let Some(scalar) = expr.as_opt::<Literal>() {
-            return Ok(ConstantArray::new(scalar.clone(), self.len()).into_array());
-        }
-
-        // Otherwise, collect the child arrays.
-        let children: Vec<_> = expr
-            .children()
-            .iter()
-            .map(|e| self.apply(e))
-            .try_collect()?;
-
-        // And wrap the scalar function up in an array.
-        let array =
-            ScalarFnArray::try_new(expr.scalar_fn().clone(), children, self.len())?.into_array();
-
-        // Optimize the resulting array's root.
-        array.optimize()
+        apply_inner(&self.to_array(), expr)
     }
 }
+
+fn apply_inner(array: &ArrayRef, expr: &Expression) -> VortexResult<ArrayRef> {
+    // If the expression is a root, return self — O(1) Arc clone.
+    if expr.is::<Root>() {
+        return Ok(array.clone());
+    }
+
+    // Manually convert literals to ConstantArray.
+    if let Some(scalar) = expr.as_opt::<Literal>() {
+        return Ok(ConstantArray::new(scalar.clone(), array.len()).into_array());
+    }
+
+    // Otherwise, collect the child arrays.
+    let children: Vec<_> = expr
+        .children()
+        .iter()
+        .map(|e| apply_inner(array, e))
+        .try_collect()?;
+
+    // And wrap the scalar function up in an array.
+    let result =
+        ScalarFnArray::try_new(expr.scalar_fn().clone(), children, array.len())?.into_array();
+
+    // Optimize the resulting array's root.
+    result.optimize()
+}