arrow_array/builder/
generic_list_builder.rs

1// Licensed to the Apache Software Foundation (ASF) under one
2// or more contributor license agreements.  See the NOTICE file
3// distributed with this work for additional information
4// regarding copyright ownership.  The ASF licenses this file
5// to you under the Apache License, Version 2.0 (the
6// "License"); you may not use this file except in compliance
7// with the License.  You may obtain a copy of the License at
8//
9//   http://www.apache.org/licenses/LICENSE-2.0
10//
11// Unless required by applicable law or agreed to in writing,
12// software distributed under the License is distributed on an
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14// KIND, either express or implied.  See the License for the
15// specific language governing permissions and limitations
16// under the License.
17
18use crate::builder::{ArrayBuilder, BufferBuilder};
19use crate::{Array, ArrayRef, GenericListArray, OffsetSizeTrait};
20use arrow_buffer::NullBufferBuilder;
21use arrow_buffer::{Buffer, OffsetBuffer};
22use arrow_schema::{Field, FieldRef};
23use std::any::Any;
24use std::sync::Arc;
25
26/// Builder for [`GenericListArray`]
27///
28/// Use [`ListBuilder`] to build [`ListArray`]s and [`LargeListBuilder`] to build [`LargeListArray`]s.
29///
30/// # Example
31///
32/// Here is code that constructs a ListArray with the contents:
33/// `[[A,B,C], [], NULL, [D], [NULL, F]]`
34///
35/// ```
36/// # use std::sync::Arc;
37/// # use arrow_array::{builder::ListBuilder, builder::StringBuilder, ArrayRef, StringArray, Array};
38/// #
39/// let values_builder = StringBuilder::new();
40/// let mut builder = ListBuilder::new(values_builder);
41///
42/// // [A, B, C]
43/// builder.values().append_value("A");
44/// builder.values().append_value("B");
45/// builder.values().append_value("C");
46/// builder.append(true);
47///
48/// // [ ] (empty list)
49/// builder.append(true);
50///
51/// // Null
52/// builder.append(false);
53///
54/// // [D]
55/// builder.values().append_value("D");
56/// builder.append(true);
57///
58/// // [NULL, F]
59/// builder.values().append_null();
60/// builder.values().append_value("F");
61/// builder.append(true);
62///
63/// // Build the array
64/// let array = builder.finish();
65///
66/// // Values is a string array
67/// // "A", "B" "C", "?", "D", NULL, "F"
68/// assert_eq!(
69///   array.values().as_ref(),
70///   &StringArray::from(vec![
71///     Some("A"), Some("B"), Some("C"),
72///     Some("D"), None, Some("F")
73///   ])
74/// );
75///
76/// // Offsets are indexes into the values array
77/// assert_eq!(
78///   array.value_offsets(),
79///   &[0, 3, 3, 3, 4, 6]
80/// );
81/// ```
82///
83/// [`ListBuilder`]: crate::builder::ListBuilder
84/// [`ListArray`]: crate::array::ListArray
85/// [`LargeListBuilder`]: crate::builder::LargeListBuilder
86/// [`LargeListArray`]: crate::array::LargeListArray
87#[derive(Debug)]
88pub struct GenericListBuilder<OffsetSize: OffsetSizeTrait, T: ArrayBuilder> {
89    offsets_builder: BufferBuilder<OffsetSize>,
90    null_buffer_builder: NullBufferBuilder,
91    values_builder: T,
92    field: Option<FieldRef>,
93}
94
95impl<O: OffsetSizeTrait, T: ArrayBuilder + Default> Default for GenericListBuilder<O, T> {
96    fn default() -> Self {
97        Self::new(T::default())
98    }
99}
100
101impl<OffsetSize: OffsetSizeTrait, T: ArrayBuilder> GenericListBuilder<OffsetSize, T> {
102    /// Creates a new [`GenericListBuilder`] from a given values array builder
103    pub fn new(values_builder: T) -> Self {
104        let capacity = values_builder.len();
105        Self::with_capacity(values_builder, capacity)
106    }
107
108    /// Creates a new [`GenericListBuilder`] from a given values array builder
109    /// `capacity` is the number of items to pre-allocate space for in this builder
110    pub fn with_capacity(values_builder: T, capacity: usize) -> Self {
111        let mut offsets_builder = BufferBuilder::<OffsetSize>::new(capacity + 1);
112        offsets_builder.append(OffsetSize::zero());
113        Self {
114            offsets_builder,
115            null_buffer_builder: NullBufferBuilder::new(capacity),
116            values_builder,
117            field: None,
118        }
119    }
120
121    /// Override the field passed to [`GenericListArray::new`]
122    ///
123    /// By default a nullable field is created with the name `item`
124    ///
125    /// Note: [`Self::finish`] and [`Self::finish_cloned`] will panic if the
126    /// field's data type does not match that of `T`
127    pub fn with_field(self, field: impl Into<FieldRef>) -> Self {
128        Self {
129            field: Some(field.into()),
130            ..self
131        }
132    }
133}
134
135impl<OffsetSize: OffsetSizeTrait, T: ArrayBuilder> ArrayBuilder
136    for GenericListBuilder<OffsetSize, T>
137where
138    T: 'static,
139{
140    /// Returns the builder as a non-mutable `Any` reference.
141    fn as_any(&self) -> &dyn Any {
142        self
143    }
144
145    /// Returns the builder as a mutable `Any` reference.
146    fn as_any_mut(&mut self) -> &mut dyn Any {
147        self
148    }
149
150    /// Returns the boxed builder as a box of `Any`.
151    fn into_box_any(self: Box<Self>) -> Box<dyn Any> {
152        self
153    }
154
155    /// Returns the number of array slots in the builder
156    fn len(&self) -> usize {
157        self.null_buffer_builder.len()
158    }
159
160    /// Builds the array and reset this builder.
161    fn finish(&mut self) -> ArrayRef {
162        Arc::new(self.finish())
163    }
164
165    /// Builds the array without resetting the builder.
166    fn finish_cloned(&self) -> ArrayRef {
167        Arc::new(self.finish_cloned())
168    }
169}
170
171impl<OffsetSize: OffsetSizeTrait, T: ArrayBuilder> GenericListBuilder<OffsetSize, T>
172where
173    T: 'static,
174{
175    /// Returns the child array builder as a mutable reference.
176    ///
177    /// This mutable reference can be used to append values into the child array builder,
178    /// but you must call [`append`](#method.append) to delimit each distinct list value.
179    pub fn values(&mut self) -> &mut T {
180        &mut self.values_builder
181    }
182
183    /// Returns the child array builder as an immutable reference
184    pub fn values_ref(&self) -> &T {
185        &self.values_builder
186    }
187
188    /// Finish the current variable-length list array slot
189    ///
190    /// # Panics
191    ///
192    /// Panics if the length of [`Self::values`] exceeds `OffsetSize::MAX`
193    #[inline]
194    pub fn append(&mut self, is_valid: bool) {
195        self.offsets_builder.append(self.next_offset());
196        self.null_buffer_builder.append(is_valid);
197    }
198
199    /// Returns the next offset
200    ///
201    /// # Panics
202    ///
203    /// Panics if the length of [`Self::values`] exceeds `OffsetSize::MAX`
204    #[inline]
205    fn next_offset(&self) -> OffsetSize {
206        OffsetSize::from_usize(self.values_builder.len()).unwrap()
207    }
208
209    /// Append a value to this [`GenericListBuilder`]
210    ///
211    /// ```
212    /// # use arrow_array::builder::{Int32Builder, ListBuilder};
213    /// # use arrow_array::cast::AsArray;
214    /// # use arrow_array::{Array, Int32Array};
215    /// # use arrow_array::types::Int32Type;
216    /// let mut builder = ListBuilder::new(Int32Builder::new());
217    ///
218    /// builder.append_value([Some(1), Some(2), Some(3)]);
219    /// builder.append_value([]);
220    /// builder.append_value([None]);
221    ///
222    /// let array = builder.finish();
223    /// assert_eq!(array.len(), 3);
224    ///
225    /// assert_eq!(array.value_offsets(), &[0, 3, 3, 4]);
226    /// let values = array.values().as_primitive::<Int32Type>();
227    /// assert_eq!(values, &Int32Array::from(vec![Some(1), Some(2), Some(3), None]));
228    /// ```
229    ///
230    /// This is an alternative API to appending directly to [`Self::values`] and
231    /// delimiting the result with [`Self::append`]
232    ///
233    /// ```
234    /// # use arrow_array::builder::{Int32Builder, ListBuilder};
235    /// # use arrow_array::cast::AsArray;
236    /// # use arrow_array::{Array, Int32Array};
237    /// # use arrow_array::types::Int32Type;
238    /// let mut builder = ListBuilder::new(Int32Builder::new());
239    ///
240    /// builder.values().append_value(1);
241    /// builder.values().append_value(2);
242    /// builder.values().append_value(3);
243    /// builder.append(true);
244    /// builder.append(true);
245    /// builder.values().append_null();
246    /// builder.append(true);
247    ///
248    /// let array = builder.finish();
249    /// assert_eq!(array.len(), 3);
250    ///
251    /// assert_eq!(array.value_offsets(), &[0, 3, 3, 4]);
252    /// let values = array.values().as_primitive::<Int32Type>();
253    /// assert_eq!(values, &Int32Array::from(vec![Some(1), Some(2), Some(3), None]));
254    /// ```
255    #[inline]
256    pub fn append_value<I, V>(&mut self, i: I)
257    where
258        T: Extend<Option<V>>,
259        I: IntoIterator<Item = Option<V>>,
260    {
261        self.extend(std::iter::once(Some(i)))
262    }
263
264    /// Append a null to this [`GenericListBuilder`]
265    ///
266    /// See [`Self::append_value`] for an example use.
267    #[inline]
268    pub fn append_null(&mut self) {
269        self.offsets_builder.append(self.next_offset());
270        self.null_buffer_builder.append_null();
271    }
272
273    /// Appends an optional value into this [`GenericListBuilder`]
274    ///
275    /// If `Some` calls [`Self::append_value`] otherwise calls [`Self::append_null`]
276    #[inline]
277    pub fn append_option<I, V>(&mut self, i: Option<I>)
278    where
279        T: Extend<Option<V>>,
280        I: IntoIterator<Item = Option<V>>,
281    {
282        match i {
283            Some(i) => self.append_value(i),
284            None => self.append_null(),
285        }
286    }
287
288    /// Builds the [`GenericListArray`] and reset this builder.
289    pub fn finish(&mut self) -> GenericListArray<OffsetSize> {
290        let values = self.values_builder.finish();
291        let nulls = self.null_buffer_builder.finish();
292
293        let offsets = self.offsets_builder.finish();
294        // Safety: Safe by construction
295        let offsets = unsafe { OffsetBuffer::new_unchecked(offsets.into()) };
296        self.offsets_builder.append(OffsetSize::zero());
297
298        let field = match &self.field {
299            Some(f) => f.clone(),
300            None => Arc::new(Field::new_list_field(values.data_type().clone(), true)),
301        };
302
303        GenericListArray::new(field, offsets, values, nulls)
304    }
305
306    /// Builds the [`GenericListArray`] without resetting the builder.
307    pub fn finish_cloned(&self) -> GenericListArray<OffsetSize> {
308        let values = self.values_builder.finish_cloned();
309        let nulls = self.null_buffer_builder.finish_cloned();
310
311        let offsets = Buffer::from_slice_ref(self.offsets_builder.as_slice());
312        // Safety: safe by construction
313        let offsets = unsafe { OffsetBuffer::new_unchecked(offsets.into()) };
314
315        let field = match &self.field {
316            Some(f) => f.clone(),
317            None => Arc::new(Field::new_list_field(values.data_type().clone(), true)),
318        };
319
320        GenericListArray::new(field, offsets, values, nulls)
321    }
322
323    /// Returns the current offsets buffer as a slice
324    pub fn offsets_slice(&self) -> &[OffsetSize] {
325        self.offsets_builder.as_slice()
326    }
327
328    /// Returns the current null buffer as a slice
329    pub fn validity_slice(&self) -> Option<&[u8]> {
330        self.null_buffer_builder.as_slice()
331    }
332}
333
334impl<O, B, V, E> Extend<Option<V>> for GenericListBuilder<O, B>
335where
336    O: OffsetSizeTrait,
337    B: ArrayBuilder + Extend<E>,
338    V: IntoIterator<Item = E>,
339{
340    #[inline]
341    fn extend<T: IntoIterator<Item = Option<V>>>(&mut self, iter: T) {
342        for v in iter {
343            match v {
344                Some(elements) => {
345                    self.values_builder.extend(elements);
346                    self.append(true);
347                }
348                None => self.append(false),
349            }
350        }
351    }
352}
353
354#[cfg(test)]
355mod tests {
356    use super::*;
357    use crate::builder::{make_builder, Int32Builder, ListBuilder};
358    use crate::cast::AsArray;
359    use crate::types::Int32Type;
360    use crate::Int32Array;
361    use arrow_schema::DataType;
362
363    fn _test_generic_list_array_builder<O: OffsetSizeTrait>() {
364        let values_builder = Int32Builder::with_capacity(10);
365        let mut builder = GenericListBuilder::<O, _>::new(values_builder);
366
367        //  [[0, 1, 2], [3, 4, 5], [6, 7]]
368        builder.values().append_value(0);
369        builder.values().append_value(1);
370        builder.values().append_value(2);
371        builder.append(true);
372        builder.values().append_value(3);
373        builder.values().append_value(4);
374        builder.values().append_value(5);
375        builder.append(true);
376        builder.values().append_value(6);
377        builder.values().append_value(7);
378        builder.append(true);
379        let list_array = builder.finish();
380
381        let list_values = list_array.values().as_primitive::<Int32Type>();
382        assert_eq!(list_values.values(), &[0, 1, 2, 3, 4, 5, 6, 7]);
383        assert_eq!(list_array.value_offsets(), [0, 3, 6, 8].map(O::usize_as));
384        assert_eq!(DataType::Int32, list_array.value_type());
385        assert_eq!(3, list_array.len());
386        assert_eq!(0, list_array.null_count());
387        assert_eq!(O::from_usize(6).unwrap(), list_array.value_offsets()[2]);
388        assert_eq!(O::from_usize(2).unwrap(), list_array.value_length(2));
389        for i in 0..3 {
390            assert!(list_array.is_valid(i));
391            assert!(!list_array.is_null(i));
392        }
393    }
394
395    #[test]
396    fn test_list_array_builder() {
397        _test_generic_list_array_builder::<i32>()
398    }
399
400    #[test]
401    fn test_large_list_array_builder() {
402        _test_generic_list_array_builder::<i64>()
403    }
404
405    fn _test_generic_list_array_builder_nulls<O: OffsetSizeTrait>() {
406        let values_builder = Int32Builder::with_capacity(10);
407        let mut builder = GenericListBuilder::<O, _>::new(values_builder);
408
409        //  [[0, 1, 2], null, [3, null, 5], [6, 7]]
410        builder.values().append_value(0);
411        builder.values().append_value(1);
412        builder.values().append_value(2);
413        builder.append(true);
414        builder.append(false);
415        builder.values().append_value(3);
416        builder.values().append_null();
417        builder.values().append_value(5);
418        builder.append(true);
419        builder.values().append_value(6);
420        builder.values().append_value(7);
421        builder.append(true);
422
423        let list_array = builder.finish();
424
425        assert_eq!(DataType::Int32, list_array.value_type());
426        assert_eq!(4, list_array.len());
427        assert_eq!(1, list_array.null_count());
428        assert_eq!(O::from_usize(3).unwrap(), list_array.value_offsets()[2]);
429        assert_eq!(O::from_usize(3).unwrap(), list_array.value_length(2));
430    }
431
432    #[test]
433    fn test_list_array_builder_nulls() {
434        _test_generic_list_array_builder_nulls::<i32>()
435    }
436
437    #[test]
438    fn test_large_list_array_builder_nulls() {
439        _test_generic_list_array_builder_nulls::<i64>()
440    }
441
442    #[test]
443    fn test_list_array_builder_finish() {
444        let values_builder = Int32Array::builder(5);
445        let mut builder = ListBuilder::new(values_builder);
446
447        builder.values().append_slice(&[1, 2, 3]);
448        builder.append(true);
449        builder.values().append_slice(&[4, 5, 6]);
450        builder.append(true);
451
452        let mut arr = builder.finish();
453        assert_eq!(2, arr.len());
454        assert!(builder.is_empty());
455
456        builder.values().append_slice(&[7, 8, 9]);
457        builder.append(true);
458        arr = builder.finish();
459        assert_eq!(1, arr.len());
460        assert!(builder.is_empty());
461    }
462
463    #[test]
464    fn test_list_array_builder_finish_cloned() {
465        let values_builder = Int32Array::builder(5);
466        let mut builder = ListBuilder::new(values_builder);
467
468        builder.values().append_slice(&[1, 2, 3]);
469        builder.append(true);
470        builder.values().append_slice(&[4, 5, 6]);
471        builder.append(true);
472
473        let mut arr = builder.finish_cloned();
474        assert_eq!(2, arr.len());
475        assert!(!builder.is_empty());
476
477        builder.values().append_slice(&[7, 8, 9]);
478        builder.append(true);
479        arr = builder.finish();
480        assert_eq!(3, arr.len());
481        assert!(builder.is_empty());
482    }
483
484    #[test]
485    fn test_list_list_array_builder() {
486        let primitive_builder = Int32Builder::with_capacity(10);
487        let values_builder = ListBuilder::new(primitive_builder);
488        let mut builder = ListBuilder::new(values_builder);
489
490        //  [[[1, 2], [3, 4]], [[5, 6, 7], null, [8]], null, [[9, 10]]]
491        builder.values().values().append_value(1);
492        builder.values().values().append_value(2);
493        builder.values().append(true);
494        builder.values().values().append_value(3);
495        builder.values().values().append_value(4);
496        builder.values().append(true);
497        builder.append(true);
498
499        builder.values().values().append_value(5);
500        builder.values().values().append_value(6);
501        builder.values().values().append_value(7);
502        builder.values().append(true);
503        builder.values().append(false);
504        builder.values().values().append_value(8);
505        builder.values().append(true);
506        builder.append(true);
507
508        builder.append(false);
509
510        builder.values().values().append_value(9);
511        builder.values().values().append_value(10);
512        builder.values().append(true);
513        builder.append(true);
514
515        let l1 = builder.finish();
516
517        assert_eq!(4, l1.len());
518        assert_eq!(1, l1.null_count());
519
520        assert_eq!(l1.value_offsets(), &[0, 2, 5, 5, 6]);
521        let l2 = l1.values().as_list::<i32>();
522
523        assert_eq!(6, l2.len());
524        assert_eq!(1, l2.null_count());
525        assert_eq!(l2.value_offsets(), &[0, 2, 4, 7, 7, 8, 10]);
526
527        let i1 = l2.values().as_primitive::<Int32Type>();
528        assert_eq!(10, i1.len());
529        assert_eq!(0, i1.null_count());
530        assert_eq!(i1.values(), &[1, 2, 3, 4, 5, 6, 7, 8, 9, 10]);
531    }
532
533    #[test]
534    fn test_extend() {
535        let mut builder = ListBuilder::new(Int32Builder::new());
536        builder.extend([
537            Some(vec![Some(1), Some(2), Some(7), None]),
538            Some(vec![]),
539            Some(vec![Some(4), Some(5)]),
540            None,
541        ]);
542
543        let array = builder.finish();
544        assert_eq!(array.value_offsets(), [0, 4, 4, 6, 6]);
545        assert_eq!(array.null_count(), 1);
546        assert_eq!(array.logical_null_count(), 1);
547        assert!(array.is_null(3));
548        let elements = array.values().as_primitive::<Int32Type>();
549        assert_eq!(elements.values(), &[1, 2, 7, 0, 4, 5]);
550        assert_eq!(elements.null_count(), 1);
551        assert_eq!(elements.logical_null_count(), 1);
552        assert!(elements.is_null(3));
553    }
554
555    #[test]
556    fn test_boxed_primitive_array_builder() {
557        let values_builder = make_builder(&DataType::Int32, 5);
558        let mut builder = ListBuilder::new(values_builder);
559
560        builder
561            .values()
562            .as_any_mut()
563            .downcast_mut::<Int32Builder>()
564            .expect("should be an Int32Builder")
565            .append_slice(&[1, 2, 3]);
566        builder.append(true);
567
568        builder
569            .values()
570            .as_any_mut()
571            .downcast_mut::<Int32Builder>()
572            .expect("should be an Int32Builder")
573            .append_slice(&[4, 5, 6]);
574        builder.append(true);
575
576        let arr = builder.finish();
577        assert_eq!(2, arr.len());
578
579        let elements = arr.values().as_primitive::<Int32Type>();
580        assert_eq!(elements.values(), &[1, 2, 3, 4, 5, 6]);
581    }
582
583    #[test]
584    fn test_boxed_list_list_array_builder() {
585        // This test is same as `test_list_list_array_builder` but uses boxed builders.
586        let values_builder = make_builder(
587            &DataType::List(Arc::new(Field::new_list_field(DataType::Int32, true))),
588            10,
589        );
590        test_boxed_generic_list_generic_list_array_builder::<i32>(values_builder);
591    }
592
593    #[test]
594    fn test_boxed_large_list_large_list_array_builder() {
595        // This test is same as `test_list_list_array_builder` but uses boxed builders.
596        let values_builder = make_builder(
597            &DataType::LargeList(Arc::new(Field::new_list_field(DataType::Int32, true))),
598            10,
599        );
600        test_boxed_generic_list_generic_list_array_builder::<i64>(values_builder);
601    }
602
603    fn test_boxed_generic_list_generic_list_array_builder<O: OffsetSizeTrait + PartialEq>(
604        values_builder: Box<dyn ArrayBuilder>,
605    ) {
606        let mut builder: GenericListBuilder<O, Box<dyn ArrayBuilder>> =
607            GenericListBuilder::<O, Box<dyn ArrayBuilder>>::new(values_builder);
608
609        //  [[[1, 2], [3, 4]], [[5, 6, 7], null, [8]], null, [[9, 10]]]
610        builder
611            .values()
612            .as_any_mut()
613            .downcast_mut::<GenericListBuilder<O, Box<dyn ArrayBuilder>>>()
614            .expect("should be an (Large)ListBuilder")
615            .values()
616            .as_any_mut()
617            .downcast_mut::<Int32Builder>()
618            .expect("should be an Int32Builder")
619            .append_value(1);
620        builder
621            .values()
622            .as_any_mut()
623            .downcast_mut::<GenericListBuilder<O, Box<dyn ArrayBuilder>>>()
624            .expect("should be an (Large)ListBuilder")
625            .values()
626            .as_any_mut()
627            .downcast_mut::<Int32Builder>()
628            .expect("should be an Int32Builder")
629            .append_value(2);
630        builder
631            .values()
632            .as_any_mut()
633            .downcast_mut::<GenericListBuilder<O, Box<dyn ArrayBuilder>>>()
634            .expect("should be an (Large)ListBuilder")
635            .append(true);
636        builder
637            .values()
638            .as_any_mut()
639            .downcast_mut::<GenericListBuilder<O, Box<dyn ArrayBuilder>>>()
640            .expect("should be an (Large)ListBuilder")
641            .values()
642            .as_any_mut()
643            .downcast_mut::<Int32Builder>()
644            .expect("should be an Int32Builder")
645            .append_value(3);
646        builder
647            .values()
648            .as_any_mut()
649            .downcast_mut::<GenericListBuilder<O, Box<dyn ArrayBuilder>>>()
650            .expect("should be an (Large)ListBuilder")
651            .values()
652            .as_any_mut()
653            .downcast_mut::<Int32Builder>()
654            .expect("should be an Int32Builder")
655            .append_value(4);
656        builder
657            .values()
658            .as_any_mut()
659            .downcast_mut::<GenericListBuilder<O, Box<dyn ArrayBuilder>>>()
660            .expect("should be an (Large)ListBuilder")
661            .append(true);
662        builder.append(true);
663
664        builder
665            .values()
666            .as_any_mut()
667            .downcast_mut::<GenericListBuilder<O, Box<dyn ArrayBuilder>>>()
668            .expect("should be an (Large)ListBuilder")
669            .values()
670            .as_any_mut()
671            .downcast_mut::<Int32Builder>()
672            .expect("should be an Int32Builder")
673            .append_value(5);
674        builder
675            .values()
676            .as_any_mut()
677            .downcast_mut::<GenericListBuilder<O, Box<dyn ArrayBuilder>>>()
678            .expect("should be an (Large)ListBuilder")
679            .values()
680            .as_any_mut()
681            .downcast_mut::<Int32Builder>()
682            .expect("should be an Int32Builder")
683            .append_value(6);
684        builder
685            .values()
686            .as_any_mut()
687            .downcast_mut::<GenericListBuilder<O, Box<dyn ArrayBuilder>>>()
688            .expect("should be an (Large)ListBuilder")
689            .values()
690            .as_any_mut()
691            .downcast_mut::<Int32Builder>()
692            .expect("should be an (Large)ListBuilder")
693            .append_value(7);
694        builder
695            .values()
696            .as_any_mut()
697            .downcast_mut::<GenericListBuilder<O, Box<dyn ArrayBuilder>>>()
698            .expect("should be an (Large)ListBuilder")
699            .append(true);
700        builder
701            .values()
702            .as_any_mut()
703            .downcast_mut::<GenericListBuilder<O, Box<dyn ArrayBuilder>>>()
704            .expect("should be an (Large)ListBuilder")
705            .append(false);
706        builder
707            .values()
708            .as_any_mut()
709            .downcast_mut::<GenericListBuilder<O, Box<dyn ArrayBuilder>>>()
710            .expect("should be an (Large)ListBuilder")
711            .values()
712            .as_any_mut()
713            .downcast_mut::<Int32Builder>()
714            .expect("should be an Int32Builder")
715            .append_value(8);
716        builder
717            .values()
718            .as_any_mut()
719            .downcast_mut::<GenericListBuilder<O, Box<dyn ArrayBuilder>>>()
720            .expect("should be an (Large)ListBuilder")
721            .append(true);
722        builder.append(true);
723
724        builder.append(false);
725
726        builder
727            .values()
728            .as_any_mut()
729            .downcast_mut::<GenericListBuilder<O, Box<dyn ArrayBuilder>>>()
730            .expect("should be an (Large)ListBuilder")
731            .values()
732            .as_any_mut()
733            .downcast_mut::<Int32Builder>()
734            .expect("should be an Int32Builder")
735            .append_value(9);
736        builder
737            .values()
738            .as_any_mut()
739            .downcast_mut::<GenericListBuilder<O, Box<dyn ArrayBuilder>>>()
740            .expect("should be an (Large)ListBuilder")
741            .values()
742            .as_any_mut()
743            .downcast_mut::<Int32Builder>()
744            .expect("should be an Int32Builder")
745            .append_value(10);
746        builder
747            .values()
748            .as_any_mut()
749            .downcast_mut::<GenericListBuilder<O, Box<dyn ArrayBuilder>>>()
750            .expect("should be an (Large)ListBuilder")
751            .append(true);
752        builder.append(true);
753
754        let l1 = builder.finish();
755
756        assert_eq!(4, l1.len());
757        assert_eq!(1, l1.null_count());
758
759        assert_eq!(l1.value_offsets(), &[0, 2, 5, 5, 6].map(O::usize_as));
760        let l2 = l1.values().as_list::<O>();
761
762        assert_eq!(6, l2.len());
763        assert_eq!(1, l2.null_count());
764        assert_eq!(l2.value_offsets(), &[0, 2, 4, 7, 7, 8, 10].map(O::usize_as));
765
766        let i1 = l2.values().as_primitive::<Int32Type>();
767        assert_eq!(10, i1.len());
768        assert_eq!(0, i1.null_count());
769        assert_eq!(i1.values(), &[1, 2, 3, 4, 5, 6, 7, 8, 9, 10]);
770    }
771
772    #[test]
773    fn test_with_field() {
774        let field = Arc::new(Field::new("bar", DataType::Int32, false));
775        let mut builder = ListBuilder::new(Int32Builder::new()).with_field(field.clone());
776        builder.append_value([Some(1), Some(2), Some(3)]);
777        builder.append_null(); // This is fine as nullability refers to nullability of values
778        builder.append_value([Some(4)]);
779        let array = builder.finish();
780        assert_eq!(array.len(), 3);
781        assert_eq!(array.data_type(), &DataType::List(field.clone()));
782
783        builder.append_value([Some(4), Some(5)]);
784        let array = builder.finish();
785        assert_eq!(array.data_type(), &DataType::List(field));
786        assert_eq!(array.len(), 1);
787    }
788
789    #[test]
790    #[should_panic(expected = "Non-nullable field of ListArray \\\"item\\\" cannot contain nulls")]
791    fn test_checks_nullability() {
792        let field = Arc::new(Field::new_list_field(DataType::Int32, false));
793        let mut builder = ListBuilder::new(Int32Builder::new()).with_field(field.clone());
794        builder.append_value([Some(1), None]);
795        builder.finish();
796    }
797
798    #[test]
799    #[should_panic(expected = "ListArray expected data type Int64 got Int32")]
800    fn test_checks_data_type() {
801        let field = Arc::new(Field::new_list_field(DataType::Int64, false));
802        let mut builder = ListBuilder::new(Int32Builder::new()).with_field(field.clone());
803        builder.append_value([Some(1)]);
804        builder.finish();
805    }
806}
arrow_array/builder/generic_list_builder.rs

arrow_array/builder/
generic_list_builder.rs
