Add lambda expressions

vortex-array/src/expr/analysis/immediate_access.rs

@@ -42,7 +42,7 @@ pub fn make_free_field_annotator(
 ) -> impl AnnotationFn<Expression, Annotation = FieldName> {
     move |expr: &Expression| match expr {
         Expression::Root => scope.names().iter().cloned().collect(),
-        Expression::Variable(_) => vec![],
+        Expression::Lambda(_) | Expression::Variable(_) => vec![],
         Expression::Scalar {
             scalar_fn,
             children,
@@ -72,7 +72,7 @@ pub fn make_bound_free_field_annotator(
 ) -> impl AnnotationFn<BoundExpression, Annotation = FieldName> {
     move |expr: &BoundExpression| match expr {
         BoundExpression::Root { .. } => scope.names().iter().cloned().collect(),
-        BoundExpression::Variable(_) => vec![],
+        BoundExpression::Lambda(_) | BoundExpression::Variable(_) => vec![],
         BoundExpression::Scalar {
             scalar_fn,
             children,

vortex-array/src/expr/analysis/infallible.rs

@@ -17,8 +17,8 @@ pub fn label_infallible(expr: &Expression) -> BooleanLabels<'_> {
             Expression::Scalar { scalar_fn, .. } => scalar_fn.signature().is_infallible(),
             // The scope itself cannot fail.
             Expression::Root => true,
-            // References are vacuously infallible.
-            Expression::Variable(_) => true,
+            // Fallibility is determined by the enclosing HOF.
+            Expression::Lambda(_) | Expression::Variable(_) => true,
         },
         |acc, &child| acc & child,
     )

vortex-array/src/expr/analysis/strict.rs

@@ -14,8 +14,9 @@ pub fn label_strict(expr: &Expression) -> BooleanLabels<'_> {
         expr,
         |expr| match expr {
             Expression::Scalar { scalar_fn, .. } => scalar_fn.signature().is_strict(),
-            // Vacuously strict.
-            Expression::Root | Expression::Variable(_) => true,
+            Expression::Root => true,
+            // Strictness is determined by the enclosing HOF.
+            Expression::Variable(_) | Expression::Lambda(_) => true,
         },
         |acc, &child| acc & child,
     )