vortex_sequence/compute/
cast.rs

1// SPDX-License-Identifier: Apache-2.0
2// SPDX-FileCopyrightText: Copyright the Vortex contributors
3
4use vortex_array::ArrayRef;
5use vortex_array::IntoArray;
6use vortex_array::dtype::DType;
7use vortex_array::dtype::Nullability;
8use vortex_array::scalar::Scalar;
9use vortex_array::scalar::ScalarValue;
10use vortex_array::scalar_fn::fns::cast::CastReduce;
11use vortex_error::VortexResult;
12use vortex_error::vortex_err;
13
14use crate::SequenceArray;
15use crate::SequenceVTable;
16
17impl CastReduce for SequenceVTable {
18    fn cast(array: &SequenceArray, dtype: &DType) -> VortexResult<Option<ArrayRef>> {
19        // SequenceArray represents arithmetic sequences (base + i * multiplier) which
20        // only makes sense for integer types. Floating-point sequences would accumulate
21        // rounding errors, and other types don't support arithmetic operations.
22        let DType::Primitive(target_ptype, target_nullability) = dtype else {
23            return Ok(None);
24        };
25
26        if !target_ptype.is_int() {
27            return Ok(None);
28        }
29
30        // Check if this is just a nullability change
31        if array.ptype() == *target_ptype && array.dtype().nullability() != *target_nullability {
32            // For SequenceArray, we can just create a new one with the same parameters
33            // but different nullability
34            return Ok(Some(
35                SequenceArray::try_new(
36                    array.base(),
37                    array.multiplier(),
38                    *target_ptype,
39                    *target_nullability,
40                    array.len(),
41                )?
42                .into_array(),
43            ));
44        }
45
46        // For type changes, we need to cast the base and multiplier
47        if array.ptype() != *target_ptype {
48            // Create scalars from PValues and cast them
49            let base_scalar = Scalar::try_new(
50                DType::Primitive(array.ptype(), Nullability::NonNullable),
51                Some(ScalarValue::Primitive(array.base())),
52            )?;
53            let multiplier_scalar = Scalar::try_new(
54                DType::Primitive(array.ptype(), Nullability::NonNullable),
55                Some(ScalarValue::Primitive(array.multiplier())),
56            )?;
57
58            let new_base_scalar =
59                base_scalar.cast(&DType::Primitive(*target_ptype, Nullability::NonNullable))?;
60            let new_multiplier_scalar = multiplier_scalar
61                .cast(&DType::Primitive(*target_ptype, Nullability::NonNullable))?;
62
63            // Extract PValues from the casted scalars
64            let new_base = new_base_scalar
65                .as_primitive()
66                .pvalue()
67                .ok_or_else(|| vortex_err!("Cast resulted in null base value"))?;
68            let new_multiplier = new_multiplier_scalar
69                .as_primitive()
70                .pvalue()
71                .ok_or_else(|| vortex_err!("Cast resulted in null multiplier value"))?;
72
73            return Ok(Some(
74                SequenceArray::try_new(
75                    new_base,
76                    new_multiplier,
77                    *target_ptype,
78                    *target_nullability,
79                    array.len(),
80                )?
81                .into_array(),
82            ));
83        }
84
85        Ok(None)
86    }
87}
88
89#[cfg(test)]
90mod tests {
91    use rstest::rstest;
92    use vortex_array::ToCanonical;
93    use vortex_array::arrays::PrimitiveArray;
94    use vortex_array::assert_arrays_eq;
95    use vortex_array::builtins::ArrayBuiltins;
96    use vortex_array::compute::conformance::cast::test_cast_conformance;
97    use vortex_array::dtype::DType;
98    use vortex_array::dtype::Nullability;
99    use vortex_array::dtype::PType;
100
101    use crate::SequenceArray;
102
103    #[test]
104    fn test_cast_sequence_nullability() {
105        let sequence =
106            SequenceArray::try_new_typed(0u32, 1u32, Nullability::NonNullable, 4).unwrap();
107
108        // Cast to nullable
109        let casted = sequence
110            .to_array()
111            .cast(DType::Primitive(PType::U32, Nullability::Nullable))
112            .unwrap();
113        assert_eq!(
114            casted.dtype(),
115            &DType::Primitive(PType::U32, Nullability::Nullable)
116        );
117    }
118
119    #[test]
120    fn test_cast_sequence_u32_to_i64() {
121        let sequence =
122            SequenceArray::try_new_typed(100u32, 10u32, Nullability::NonNullable, 4).unwrap();
123
124        let casted = sequence
125            .to_array()
126            .cast(DType::Primitive(PType::I64, Nullability::NonNullable))
127            .unwrap();
128        assert_eq!(
129            casted.dtype(),
130            &DType::Primitive(PType::I64, Nullability::NonNullable)
131        );
132
133        // Verify the values
134        let decoded = casted.to_primitive();
135        assert_arrays_eq!(decoded, PrimitiveArray::from_iter([100i64, 110, 120, 130]));
136    }
137
138    #[test]
139    fn test_cast_sequence_i16_to_i32_nullable() {
140        // Test ptype change AND nullability change in one cast
141        let sequence =
142            SequenceArray::try_new_typed(5i16, 3i16, Nullability::NonNullable, 3).unwrap();
143
144        let casted = sequence
145            .to_array()
146            .cast(DType::Primitive(PType::I32, Nullability::Nullable))
147            .unwrap();
148        assert_eq!(
149            casted.dtype(),
150            &DType::Primitive(PType::I32, Nullability::Nullable)
151        );
152
153        // Verify the values
154        let decoded = casted.to_primitive();
155        assert_arrays_eq!(
156            decoded,
157            PrimitiveArray::from_option_iter([Some(5i32), Some(8), Some(11)])
158        );
159    }
160
161    #[test]
162    fn test_cast_sequence_to_float_delegates_to_canonical() {
163        let sequence =
164            SequenceArray::try_new_typed(0i32, 1i32, Nullability::NonNullable, 5).unwrap();
165
166        // Cast to float should delegate to canonical (SequenceArray doesn't support float)
167        let casted = sequence
168            .to_array()
169            .cast(DType::Primitive(PType::F32, Nullability::NonNullable))
170            .unwrap();
171        // Should still succeed by decoding to canonical first
172        assert_eq!(
173            casted.dtype(),
174            &DType::Primitive(PType::F32, Nullability::NonNullable)
175        );
176
177        // Verify the values were correctly converted
178        let decoded = casted.to_primitive();
179        assert_arrays_eq!(
180            decoded,
181            PrimitiveArray::from_iter([0.0f32, 1.0, 2.0, 3.0, 4.0])
182        );
183    }
184
185    #[rstest]
186    #[case::i32(SequenceArray::try_new_typed(0i32, 1i32, Nullability::NonNullable, 5).unwrap())]
187    #[case::u64(SequenceArray::try_new_typed(1000u64, 100u64, Nullability::NonNullable, 4).unwrap())]
188    // TODO(DK): SequenceArray does not actually conform. You cannot cast this array to u8 even
189    // though all its values are representable therein.
190    //
191    // #[case::negative_step(SequenceArray::try_new_typed(100i32, -10i32, Nullability::NonNullable,
192    // 5).unwrap())]
193    #[case::single(SequenceArray::try_new_typed(42i64, 0i64, Nullability::NonNullable, 1).unwrap())]
194    #[case::constant(SequenceArray::try_new_typed(
195        100i32,
196        0i32, // multiplier of 0 means constant array
197        Nullability::NonNullable,
198        5,
199    ).unwrap())]
200    fn test_cast_sequence_conformance(#[case] sequence: SequenceArray) {
201        test_cast_conformance(&sequence.to_array());
202    }
203}
vortex_sequence/compute/cast.rs

vortex_sequence/compute/
cast.rs
