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
13// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
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 `n` `null`s into the builder.
274    #[inline]
275    pub fn append_nulls(&mut self, n: usize) {
276        let next_offset = self.next_offset();
277        self.offsets_builder.append_n(n, next_offset);
278        self.null_buffer_builder.append_n_nulls(n);
279    }
280
281    /// Appends an optional value into this [`GenericListBuilder`]
282    ///
283    /// If `Some` calls [`Self::append_value`] otherwise calls [`Self::append_null`]
284    #[inline]
285    pub fn append_option<I, V>(&mut self, i: Option<I>)
286    where
287        T: Extend<Option<V>>,
288        I: IntoIterator<Item = Option<V>>,
289    {
290        match i {
291            Some(i) => self.append_value(i),
292            None => self.append_null(),
293        }
294    }
295
296    /// Builds the [`GenericListArray`] and reset this builder.
297    pub fn finish(&mut self) -> GenericListArray<OffsetSize> {
298        let values = self.values_builder.finish();
299        let nulls = self.null_buffer_builder.finish();
300
301        let offsets = self.offsets_builder.finish();
302        // Safety: Safe by construction
303        let offsets = unsafe { OffsetBuffer::new_unchecked(offsets.into()) };
304        self.offsets_builder.append(OffsetSize::zero());
305
306        let field = match &self.field {
307            Some(f) => f.clone(),
308            None => Arc::new(Field::new_list_field(values.data_type().clone(), true)),
309        };
310
311        GenericListArray::new(field, offsets, values, nulls)
312    }
313
314    /// Builds the [`GenericListArray`] without resetting the builder.
315    pub fn finish_cloned(&self) -> GenericListArray<OffsetSize> {
316        let values = self.values_builder.finish_cloned();
317        let nulls = self.null_buffer_builder.finish_cloned();
318
319        let offsets = Buffer::from_slice_ref(self.offsets_builder.as_slice());
320        // Safety: safe by construction
321        let offsets = unsafe { OffsetBuffer::new_unchecked(offsets.into()) };
322
323        let field = match &self.field {
324            Some(f) => f.clone(),
325            None => Arc::new(Field::new_list_field(values.data_type().clone(), true)),
326        };
327
328        GenericListArray::new(field, offsets, values, nulls)
329    }
330
331    /// Returns the current offsets buffer as a slice
332    pub fn offsets_slice(&self) -> &[OffsetSize] {
333        self.offsets_builder.as_slice()
334    }
335
336    /// Returns the current null buffer as a slice
337    pub fn validity_slice(&self) -> Option<&[u8]> {
338        self.null_buffer_builder.as_slice()
339    }
340}
341
342impl<O, B, V, E> Extend<Option<V>> for GenericListBuilder<O, B>
343where
344    O: OffsetSizeTrait,
345    B: ArrayBuilder + Extend<E>,
346    V: IntoIterator<Item = E>,
347{
348    #[inline]
349    fn extend<T: IntoIterator<Item = Option<V>>>(&mut self, iter: T) {
350        for v in iter {
351            match v {
352                Some(elements) => {
353                    self.values_builder.extend(elements);
354                    self.append(true);
355                }
356                None => self.append(false),
357            }
358        }
359    }
360}
361
362#[cfg(test)]
363mod tests {
364    use super::*;
365    use crate::builder::{make_builder, Int32Builder, ListBuilder};
366    use crate::cast::AsArray;
367    use crate::types::Int32Type;
368    use crate::Int32Array;
369    use arrow_schema::DataType;
370
371    fn _test_generic_list_array_builder<O: OffsetSizeTrait>() {
372        let values_builder = Int32Builder::with_capacity(10);
373        let mut builder = GenericListBuilder::<O, _>::new(values_builder);
374
375        //  [[0, 1, 2], [3, 4, 5], [6, 7]]
376        builder.values().append_value(0);
377        builder.values().append_value(1);
378        builder.values().append_value(2);
379        builder.append(true);
380        builder.values().append_value(3);
381        builder.values().append_value(4);
382        builder.values().append_value(5);
383        builder.append(true);
384        builder.values().append_value(6);
385        builder.values().append_value(7);
386        builder.append(true);
387        let list_array = builder.finish();
388
389        let list_values = list_array.values().as_primitive::<Int32Type>();
390        assert_eq!(list_values.values(), &[0, 1, 2, 3, 4, 5, 6, 7]);
391        assert_eq!(list_array.value_offsets(), [0, 3, 6, 8].map(O::usize_as));
392        assert_eq!(DataType::Int32, list_array.value_type());
393        assert_eq!(3, list_array.len());
394        assert_eq!(0, list_array.null_count());
395        assert_eq!(O::from_usize(6).unwrap(), list_array.value_offsets()[2]);
396        assert_eq!(O::from_usize(2).unwrap(), list_array.value_length(2));
397        for i in 0..3 {
398            assert!(list_array.is_valid(i));
399            assert!(!list_array.is_null(i));
400        }
401    }
402
403    #[test]
404    fn test_list_array_builder() {
405        _test_generic_list_array_builder::<i32>()
406    }
407
408    #[test]
409    fn test_large_list_array_builder() {
410        _test_generic_list_array_builder::<i64>()
411    }
412
413    fn _test_generic_list_array_builder_nulls<O: OffsetSizeTrait>() {
414        let values_builder = Int32Builder::with_capacity(10);
415        let mut builder = GenericListBuilder::<O, _>::new(values_builder);
416
417        //  [[0, 1, 2], null, [3, null, 5], [6, 7], null, null, [8]]
418        builder.values().append_value(0);
419        builder.values().append_value(1);
420        builder.values().append_value(2);
421        builder.append(true);
422        builder.append(false);
423        builder.values().append_value(3);
424        builder.values().append_null();
425        builder.values().append_value(5);
426        builder.append(true);
427        builder.values().append_value(6);
428        builder.values().append_value(7);
429        builder.append(true);
430        builder.append_nulls(2);
431        builder.values().append_value(8);
432        builder.append(true);
433
434        let list_array = builder.finish();
435
436        assert_eq!(DataType::Int32, list_array.value_type());
437        assert_eq!(7, list_array.len());
438        assert_eq!(3, list_array.null_count());
439        assert_eq!(O::from_usize(3).unwrap(), list_array.value_offsets()[2]);
440        assert_eq!(O::from_usize(9).unwrap(), list_array.value_offsets()[7]);
441        assert_eq!(O::from_usize(3).unwrap(), list_array.value_length(2));
442        assert!(list_array.is_null(4));
443        assert!(list_array.is_null(5));
444    }
445
446    #[test]
447    fn test_list_array_builder_nulls() {
448        _test_generic_list_array_builder_nulls::<i32>()
449    }
450
451    #[test]
452    fn test_large_list_array_builder_nulls() {
453        _test_generic_list_array_builder_nulls::<i64>()
454    }
455
456    #[test]
457    fn test_list_array_builder_finish() {
458        let values_builder = Int32Array::builder(5);
459        let mut builder = ListBuilder::new(values_builder);
460
461        builder.values().append_slice(&[1, 2, 3]);
462        builder.append(true);
463        builder.values().append_slice(&[4, 5, 6]);
464        builder.append(true);
465
466        let mut arr = builder.finish();
467        assert_eq!(2, arr.len());
468        assert!(builder.is_empty());
469
470        builder.values().append_slice(&[7, 8, 9]);
471        builder.append(true);
472        arr = builder.finish();
473        assert_eq!(1, arr.len());
474        assert!(builder.is_empty());
475    }
476
477    #[test]
478    fn test_list_array_builder_finish_cloned() {
479        let values_builder = Int32Array::builder(5);
480        let mut builder = ListBuilder::new(values_builder);
481
482        builder.values().append_slice(&[1, 2, 3]);
483        builder.append(true);
484        builder.values().append_slice(&[4, 5, 6]);
485        builder.append(true);
486
487        let mut arr = builder.finish_cloned();
488        assert_eq!(2, arr.len());
489        assert!(!builder.is_empty());
490
491        builder.values().append_slice(&[7, 8, 9]);
492        builder.append(true);
493        arr = builder.finish();
494        assert_eq!(3, arr.len());
495        assert!(builder.is_empty());
496    }
497
498    #[test]
499    fn test_list_list_array_builder() {
500        let primitive_builder = Int32Builder::with_capacity(10);
501        let values_builder = ListBuilder::new(primitive_builder);
502        let mut builder = ListBuilder::new(values_builder);
503
504        //  [[[1, 2], [3, 4]], [[5, 6, 7], null, [8]], null, [[9, 10]]]
505        builder.values().values().append_value(1);
506        builder.values().values().append_value(2);
507        builder.values().append(true);
508        builder.values().values().append_value(3);
509        builder.values().values().append_value(4);
510        builder.values().append(true);
511        builder.append(true);
512
513        builder.values().values().append_value(5);
514        builder.values().values().append_value(6);
515        builder.values().values().append_value(7);
516        builder.values().append(true);
517        builder.values().append(false);
518        builder.values().values().append_value(8);
519        builder.values().append(true);
520        builder.append(true);
521
522        builder.append(false);
523
524        builder.values().values().append_value(9);
525        builder.values().values().append_value(10);
526        builder.values().append(true);
527        builder.append(true);
528
529        let l1 = builder.finish();
530
531        assert_eq!(4, l1.len());
532        assert_eq!(1, l1.null_count());
533
534        assert_eq!(l1.value_offsets(), &[0, 2, 5, 5, 6]);
535        let l2 = l1.values().as_list::<i32>();
536
537        assert_eq!(6, l2.len());
538        assert_eq!(1, l2.null_count());
539        assert_eq!(l2.value_offsets(), &[0, 2, 4, 7, 7, 8, 10]);
540
541        let i1 = l2.values().as_primitive::<Int32Type>();
542        assert_eq!(10, i1.len());
543        assert_eq!(0, i1.null_count());
544        assert_eq!(i1.values(), &[1, 2, 3, 4, 5, 6, 7, 8, 9, 10]);
545    }
546
547    #[test]
548    fn test_extend() {
549        let mut builder = ListBuilder::new(Int32Builder::new());
550        builder.extend([
551            Some(vec![Some(1), Some(2), Some(7), None]),
552            Some(vec![]),
553            Some(vec![Some(4), Some(5)]),
554            None,
555        ]);
556
557        let array = builder.finish();
558        assert_eq!(array.value_offsets(), [0, 4, 4, 6, 6]);
559        assert_eq!(array.null_count(), 1);
560        assert_eq!(array.logical_null_count(), 1);
561        assert!(array.is_null(3));
562        let elements = array.values().as_primitive::<Int32Type>();
563        assert_eq!(elements.values(), &[1, 2, 7, 0, 4, 5]);
564        assert_eq!(elements.null_count(), 1);
565        assert_eq!(elements.logical_null_count(), 1);
566        assert!(elements.is_null(3));
567    }
568
569    #[test]
570    fn test_boxed_primitive_array_builder() {
571        let values_builder = make_builder(&DataType::Int32, 5);
572        let mut builder = ListBuilder::new(values_builder);
573
574        builder
575            .values()
576            .as_any_mut()
577            .downcast_mut::<Int32Builder>()
578            .expect("should be an Int32Builder")
579            .append_slice(&[1, 2, 3]);
580        builder.append(true);
581
582        builder
583            .values()
584            .as_any_mut()
585            .downcast_mut::<Int32Builder>()
586            .expect("should be an Int32Builder")
587            .append_slice(&[4, 5, 6]);
588        builder.append(true);
589
590        let arr = builder.finish();
591        assert_eq!(2, arr.len());
592
593        let elements = arr.values().as_primitive::<Int32Type>();
594        assert_eq!(elements.values(), &[1, 2, 3, 4, 5, 6]);
595    }
596
597    #[test]
598    fn test_boxed_list_list_array_builder() {
599        // This test is same as `test_list_list_array_builder` but uses boxed builders.
600        let values_builder = make_builder(
601            &DataType::List(Arc::new(Field::new_list_field(DataType::Int32, true))),
602            10,
603        );
604        test_boxed_generic_list_generic_list_array_builder::<i32>(values_builder);
605    }
606
607    #[test]
608    fn test_boxed_large_list_large_list_array_builder() {
609        // This test is same as `test_list_list_array_builder` but uses boxed builders.
610        let values_builder = make_builder(
611            &DataType::LargeList(Arc::new(Field::new_list_field(DataType::Int32, true))),
612            10,
613        );
614        test_boxed_generic_list_generic_list_array_builder::<i64>(values_builder);
615    }
616
617    fn test_boxed_generic_list_generic_list_array_builder<O: OffsetSizeTrait + PartialEq>(
618        values_builder: Box<dyn ArrayBuilder>,
619    ) {
620        let mut builder: GenericListBuilder<O, Box<dyn ArrayBuilder>> =
621            GenericListBuilder::<O, Box<dyn ArrayBuilder>>::new(values_builder);
622
623        //  [[[1, 2], [3, 4]], [[5, 6, 7], null, [8]], null, [[9, 10]]]
624        builder
625            .values()
626            .as_any_mut()
627            .downcast_mut::<GenericListBuilder<O, Box<dyn ArrayBuilder>>>()
628            .expect("should be an (Large)ListBuilder")
629            .values()
630            .as_any_mut()
631            .downcast_mut::<Int32Builder>()
632            .expect("should be an Int32Builder")
633            .append_value(1);
634        builder
635            .values()
636            .as_any_mut()
637            .downcast_mut::<GenericListBuilder<O, Box<dyn ArrayBuilder>>>()
638            .expect("should be an (Large)ListBuilder")
639            .values()
640            .as_any_mut()
641            .downcast_mut::<Int32Builder>()
642            .expect("should be an Int32Builder")
643            .append_value(2);
644        builder
645            .values()
646            .as_any_mut()
647            .downcast_mut::<GenericListBuilder<O, Box<dyn ArrayBuilder>>>()
648            .expect("should be an (Large)ListBuilder")
649            .append(true);
650        builder
651            .values()
652            .as_any_mut()
653            .downcast_mut::<GenericListBuilder<O, Box<dyn ArrayBuilder>>>()
654            .expect("should be an (Large)ListBuilder")
655            .values()
656            .as_any_mut()
657            .downcast_mut::<Int32Builder>()
658            .expect("should be an Int32Builder")
659            .append_value(3);
660        builder
661            .values()
662            .as_any_mut()
663            .downcast_mut::<GenericListBuilder<O, Box<dyn ArrayBuilder>>>()
664            .expect("should be an (Large)ListBuilder")
665            .values()
666            .as_any_mut()
667            .downcast_mut::<Int32Builder>()
668            .expect("should be an Int32Builder")
669            .append_value(4);
670        builder
671            .values()
672            .as_any_mut()
673            .downcast_mut::<GenericListBuilder<O, Box<dyn ArrayBuilder>>>()
674            .expect("should be an (Large)ListBuilder")
675            .append(true);
676        builder.append(true);
677
678        builder
679            .values()
680            .as_any_mut()
681            .downcast_mut::<GenericListBuilder<O, Box<dyn ArrayBuilder>>>()
682            .expect("should be an (Large)ListBuilder")
683            .values()
684            .as_any_mut()
685            .downcast_mut::<Int32Builder>()
686            .expect("should be an Int32Builder")
687            .append_value(5);
688        builder
689            .values()
690            .as_any_mut()
691            .downcast_mut::<GenericListBuilder<O, Box<dyn ArrayBuilder>>>()
692            .expect("should be an (Large)ListBuilder")
693            .values()
694            .as_any_mut()
695            .downcast_mut::<Int32Builder>()
696            .expect("should be an Int32Builder")
697            .append_value(6);
698        builder
699            .values()
700            .as_any_mut()
701            .downcast_mut::<GenericListBuilder<O, Box<dyn ArrayBuilder>>>()
702            .expect("should be an (Large)ListBuilder")
703            .values()
704            .as_any_mut()
705            .downcast_mut::<Int32Builder>()
706            .expect("should be an (Large)ListBuilder")
707            .append_value(7);
708        builder
709            .values()
710            .as_any_mut()
711            .downcast_mut::<GenericListBuilder<O, Box<dyn ArrayBuilder>>>()
712            .expect("should be an (Large)ListBuilder")
713            .append(true);
714        builder
715            .values()
716            .as_any_mut()
717            .downcast_mut::<GenericListBuilder<O, Box<dyn ArrayBuilder>>>()
718            .expect("should be an (Large)ListBuilder")
719            .append(false);
720        builder
721            .values()
722            .as_any_mut()
723            .downcast_mut::<GenericListBuilder<O, Box<dyn ArrayBuilder>>>()
724            .expect("should be an (Large)ListBuilder")
725            .values()
726            .as_any_mut()
727            .downcast_mut::<Int32Builder>()
728            .expect("should be an Int32Builder")
729            .append_value(8);
730        builder
731            .values()
732            .as_any_mut()
733            .downcast_mut::<GenericListBuilder<O, Box<dyn ArrayBuilder>>>()
734            .expect("should be an (Large)ListBuilder")
735            .append(true);
736        builder.append(true);
737
738        builder.append(false);
739
740        builder
741            .values()
742            .as_any_mut()
743            .downcast_mut::<GenericListBuilder<O, Box<dyn ArrayBuilder>>>()
744            .expect("should be an (Large)ListBuilder")
745            .values()
746            .as_any_mut()
747            .downcast_mut::<Int32Builder>()
748            .expect("should be an Int32Builder")
749            .append_value(9);
750        builder
751            .values()
752            .as_any_mut()
753            .downcast_mut::<GenericListBuilder<O, Box<dyn ArrayBuilder>>>()
754            .expect("should be an (Large)ListBuilder")
755            .values()
756            .as_any_mut()
757            .downcast_mut::<Int32Builder>()
758            .expect("should be an Int32Builder")
759            .append_value(10);
760        builder
761            .values()
762            .as_any_mut()
763            .downcast_mut::<GenericListBuilder<O, Box<dyn ArrayBuilder>>>()
764            .expect("should be an (Large)ListBuilder")
765            .append(true);
766        builder.append(true);
767
768        let l1 = builder.finish();
769
770        assert_eq!(4, l1.len());
771        assert_eq!(1, l1.null_count());
772
773        assert_eq!(l1.value_offsets(), &[0, 2, 5, 5, 6].map(O::usize_as));
774        let l2 = l1.values().as_list::<O>();
775
776        assert_eq!(6, l2.len());
777        assert_eq!(1, l2.null_count());
778        assert_eq!(l2.value_offsets(), &[0, 2, 4, 7, 7, 8, 10].map(O::usize_as));
779
780        let i1 = l2.values().as_primitive::<Int32Type>();
781        assert_eq!(10, i1.len());
782        assert_eq!(0, i1.null_count());
783        assert_eq!(i1.values(), &[1, 2, 3, 4, 5, 6, 7, 8, 9, 10]);
784    }
785
786    #[test]
787    fn test_with_field() {
788        let field = Arc::new(Field::new("bar", DataType::Int32, false));
789        let mut builder = ListBuilder::new(Int32Builder::new()).with_field(field.clone());
790        builder.append_value([Some(1), Some(2), Some(3)]);
791        builder.append_null(); // This is fine as nullability refers to nullability of values
792        builder.append_value([Some(4)]);
793        let array = builder.finish();
794        assert_eq!(array.len(), 3);
795        assert_eq!(array.data_type(), &DataType::List(field.clone()));
796
797        builder.append_value([Some(4), Some(5)]);
798        let array = builder.finish();
799        assert_eq!(array.data_type(), &DataType::List(field));
800        assert_eq!(array.len(), 1);
801    }
802
803    #[test]
804    #[should_panic(expected = "Non-nullable field of ListArray \\\"item\\\" cannot contain nulls")]
805    fn test_checks_nullability() {
806        let field = Arc::new(Field::new_list_field(DataType::Int32, false));
807        let mut builder = ListBuilder::new(Int32Builder::new()).with_field(field.clone());
808        builder.append_value([Some(1), None]);
809        builder.finish();
810    }
811
812    #[test]
813    #[should_panic(expected = "ListArray expected data type Int64 got Int32")]
814    fn test_checks_data_type() {
815        let field = Arc::new(Field::new_list_field(DataType::Int64, false));
816        let mut builder = ListBuilder::new(Int32Builder::new()).with_field(field.clone());
817        builder.append_value([Some(1)]);
818        builder.finish();
819    }
820}
arrow_array/builder/generic_list_builder.rs

arrow_array/builder/
generic_list_builder.rs
