fix: handle [] shapes in sort

src/circuit/ops/layouts.rs

@@ -1097,6 +1097,10 @@ fn _sort_ascending<F: PrimeField + TensorType + PartialOrd + std::hash::Hash>(
     let mut input = values[0].clone();
     input.flatten();
 
+    if input.len() == 1 {
+        return Ok((input.clone(), create_zero_tensor(1)));
+    }
+
     let is_assigned = !input.any_unknowns()?;
 
     // Generate sorted tensor - if values are assigned, compute the actual sort;

src/tensor/mod.rs

@@ -926,6 +926,9 @@ impl<T: Clone + TensorType> Tensor<T> {
                 ));
             }
             self.dims = vec![];
+        }
+        if self.dims() == &[0] && new_dims.iter().product::<usize>() == 1 {
+            self.dims = Vec::from(new_dims);
         } else {
             let product = if new_dims != [0] {
                 new_dims.iter().product::<usize>()
@@ -1104,6 +1107,10 @@ impl<T: Clone + TensorType> Tensor<T> {
             let mut output = self.clone();
             output.reshape(shape)?;
             return Ok(output);
+        } else if self.dims() == &[0] && shape.iter().product::<usize>() == 1 {
+            let mut output = self.clone();
+            output.reshape(shape)?;
+            return Ok(output);
         }
 
         if self.dims().len() > shape.len() {