Doctest for GenericListArray.

arrow/src/array/array_list.rs

@@ -50,6 +50,37 @@ impl OffsetSizeTrait for i64 {
     }
 }
 
+/// Generic struct for a primitive Array
+///
+/// # Example
+/// Creates a [`GenericListArray`] from an iterator of primitive values
+/// ```
+/// # use arrow::array::{Array, GenericListArray, Int32Array};
+/// # use arrow::datatypes::{DataType, Int32Type};
+/// let data = vec![
+///    Some(vec![Some(0), Some(1), Some(2)]),
+///    None,
+///    Some(vec![Some(3), None, Some(5), Some(19)]),
+///    Some(vec![Some(6), Some(7)]),
+/// ];
+/// let list_array = GenericListArray::<i32>::from_iter_primitive::<Int32Type, _, _>(data);
+/// assert_eq!(DataType::Int32, list_array.value_type());
+/// assert_eq!(4, list_array.len());
+/// assert_eq!(1, list_array.null_count());
+/// assert_eq!(3, list_array.value_length(0));
+/// assert_eq!(0, list_array.value_length(1));
+/// assert_eq!(4, list_array.value_length(2));
+/// assert_eq!(2, list_array.value_length(3));
+/// assert_eq!(
+///     0,
+///     list_array
+///     .value(0)
+///     .as_any()
+///     .downcast_ref::<Int32Array>()
+///     .unwrap()
+///     .value(0)
+/// )
+/// ```
 pub struct GenericListArray<OffsetSize> {
     data: ArrayData,
     values: ArrayRef,
@@ -1053,4 +1084,32 @@ mod tests {
             .build();
         ListArray::from(list_data);
     }
+
+    #[test]
+    fn test_generic_list_array() {
+        let data = vec![
+            Some(vec![Some(10), Some(1), Some(2)]),
+            None,
+            Some(vec![Some(3), None, Some(5), Some(19)]),
+            Some(vec![Some(6), Some(7)]),
+        ];
+        let list_array = GenericListArray::<i32>::from_iter_primitive::<Int32Type, _, _>(data);
+        assert_eq!(DataType::Int32, list_array.value_type());
+        assert_eq!(4, list_array.len());
+        assert_eq!(1, list_array.null_count());
+
+        assert_eq!(3, list_array.value_length(0));
+        assert_eq!(0, list_array.value_length(1));
+        assert_eq!(4, list_array.value_length(2));
+        assert_eq!(2, list_array.value_length(3));
+        assert_eq!(
+            10,
+            list_array
+            .value(0)
+            .as_any()
+            .downcast_ref::<Int32Array>()
+            .unwrap()
+            .value(0)
+        );
+    }
 }