vortex_alp/alp/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::ArrayView;
6use vortex_array::IntoArray;
7use vortex_array::builtins::ArrayBuiltins;
8use vortex_array::dtype::DType;
9use vortex_array::scalar_fn::fns::cast::CastReduce;
10use vortex_error::VortexResult;
11
12use crate::ALPArrayExt;
13use crate::ALPArraySlotsExt;
14use crate::alp::ALP;
15
16impl CastReduce for ALP {
17    fn cast(array: ArrayView<'_, Self>, dtype: &DType) -> VortexResult<Option<ArrayRef>> {
18        // Check if this is just a nullability change
19        if !array.dtype().eq_ignore_nullability(dtype) {
20            return Ok(None);
21        }
22
23        // For nullability-only changes, we can avoid decoding
24        // Cast the encoded array (integers) to handle nullability
25        let new_encoded = array.encoded().cast(
26            array
27                .encoded()
28                .dtype()
29                .with_nullability(dtype.nullability()),
30        )?;
31
32        let new_patches = array
33            .patches()
34            .map(|p| p.map_values(|v| v.cast(dtype.clone())))
35            .transpose()?;
36
37        // SAFETY: casting nullability doesn't alter the invariants
38        unsafe {
39            Ok(Some(
40                ALP::new_unchecked(new_encoded, array.exponents(), new_patches).into_array(),
41            ))
42        }
43    }
44}
45
46#[cfg(test)]
47mod tests {
48    use std::sync::LazyLock;
49
50    use rstest::rstest;
51    use vortex_array::IntoArray;
52    use vortex_array::VortexSessionExecute;
53    use vortex_array::arrays::PrimitiveArray;
54    use vortex_array::assert_arrays_eq;
55    use vortex_array::builtins::ArrayBuiltins;
56    use vortex_array::compute::conformance::cast::test_cast_conformance;
57    use vortex_array::dtype::DType;
58    use vortex_array::dtype::Nullability;
59    use vortex_array::dtype::PType;
60    use vortex_buffer::buffer;
61    use vortex_error::VortexExpect;
62    use vortex_error::VortexResult;
63    use vortex_session::VortexSession;
64
65    use crate::alp::array::ALPArrayExt;
66    use crate::alp_encode;
67
68    static SESSION: LazyLock<VortexSession> = LazyLock::new(|| {
69        let session = vortex_array::array_session();
70        crate::initialize(&session);
71        session
72    });
73
74    #[test]
75    fn issue_5766_test_cast_alp_with_patches_to_nullable() -> VortexResult<()> {
76        let mut ctx = SESSION.create_execution_ctx();
77        let values = buffer![1.234f32, f32::NAN, 2.345, f32::INFINITY, 3.456].into_array();
78        let values_primitive = values.clone().execute::<PrimitiveArray>(&mut ctx)?;
79        let alp = alp_encode(values_primitive.as_view(), None, &mut ctx)?;
80
81        assert!(
82            alp.patches().is_some(),
83            "Test requires ALP array with patches"
84        );
85
86        let nullable_dtype = DType::Primitive(PType::F32, Nullability::Nullable);
87        let casted = alp.into_array().cast(nullable_dtype.clone())?;
88
89        let expected = values.cast(nullable_dtype)?;
90
91        assert_arrays_eq!(casted, expected, &mut ctx);
92
93        Ok(())
94    }
95
96    #[test]
97    fn test_cast_alp_f32_to_f64() -> VortexResult<()> {
98        let mut ctx = SESSION.create_execution_ctx();
99        let values = buffer![1.5f32, 2.5, 3.5, 4.5].into_array();
100        let values_primitive = values.execute::<PrimitiveArray>(&mut ctx)?;
101        let alp = alp_encode(values_primitive.as_view(), None, &mut ctx)?;
102
103        let casted = alp
104            .into_array()
105            .cast(DType::Primitive(PType::F64, Nullability::NonNullable))?;
106        assert_eq!(
107            casted.dtype(),
108            &DType::Primitive(PType::F64, Nullability::NonNullable)
109        );
110
111        assert_arrays_eq!(
112            casted,
113            PrimitiveArray::from_iter([1.5f64, 2.5, 3.5, 4.5]),
114            &mut ctx
115        );
116
117        Ok(())
118    }
119
120    #[test]
121    fn test_cast_alp_to_int() -> VortexResult<()> {
122        let mut ctx = SESSION.create_execution_ctx();
123        let values = buffer![1.0f32, 2.0, 3.0, 4.0].into_array();
124        let values_primitive = values.execute::<PrimitiveArray>(&mut ctx)?;
125        let alp = alp_encode(values_primitive.as_view(), None, &mut ctx)?;
126
127        let casted = alp
128            .into_array()
129            .cast(DType::Primitive(PType::I32, Nullability::NonNullable))?;
130        assert_eq!(
131            casted.dtype(),
132            &DType::Primitive(PType::I32, Nullability::NonNullable)
133        );
134
135        assert_arrays_eq!(casted, PrimitiveArray::from_iter([1i32, 2, 3, 4]), &mut ctx);
136
137        Ok(())
138    }
139
140    #[rstest]
141    #[case(buffer![1.23f32, 4.56, 7.89, 10.11, 12.13].into_array())]
142    #[case(buffer![100.1f64, 200.2, 300.3, 400.4, 500.5].into_array())]
143    #[case(PrimitiveArray::from_option_iter([Some(1.1f32), None, Some(2.2), Some(3.3), None]).into_array())]
144    #[case(buffer![42.42f64].into_array())]
145    #[case(buffer![0.0f32, -1.5, 2.5, -3.5, 4.5].into_array())]
146    fn test_cast_alp_conformance(#[case] array: vortex_array::ArrayRef) -> VortexResult<()> {
147        let mut ctx = SESSION.create_execution_ctx();
148        let array_primitive = array.execute::<PrimitiveArray>(&mut ctx)?;
149        let alp =
150            alp_encode(array_primitive.as_view(), None, &mut ctx).vortex_expect("cannot fail");
151        test_cast_conformance(&alp.into_array(), &mut ctx);
152
153        Ok(())
154    }
155}
vortex_alp/alp/compute/cast.rs

vortex_alp/alp/compute/
cast.rs
