Add row conditions

crates/nu-parser/src/flatten.rs

@@ -114,6 +114,7 @@ pub fn flatten_expression(
         Expr::String(_) => {
             vec![(expr.span, FlatShape::String)]
         }
+        Expr::RowCondition(_, expr) => flatten_expression(working_set, expr),
         Expr::Subexpression(block_id) => {
             flatten_block(working_set, working_set.get_block(*block_id))
         }