1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
use std::{cmp, collections, hash};

#[cfg(feature = "experimental-inspect")]
use crate::inspect::types::TypeInfo;
use crate::{
    instance::Bound,
    types::any::PyAnyMethods,
    types::frozenset::PyFrozenSetMethods,
    types::set::{new_from_iter, PySetMethods},
    types::{PyFrozenSet, PySet},
    FromPyObject, IntoPy, PyAny, PyErr, PyObject, PyResult, Python, ToPyObject,
};

impl<T, S> ToPyObject for collections::HashSet<T, S>
where
    T: hash::Hash + Eq + ToPyObject,
    S: hash::BuildHasher + Default,
{
    fn to_object(&self, py: Python<'_>) -> PyObject {
        new_from_iter(py, self)
            .expect("Failed to create Python set from HashSet")
            .into()
    }
}

impl<T> ToPyObject for collections::BTreeSet<T>
where
    T: hash::Hash + Eq + ToPyObject,
{
    fn to_object(&self, py: Python<'_>) -> PyObject {
        new_from_iter(py, self)
            .expect("Failed to create Python set from BTreeSet")
            .into()
    }
}

impl<K, S> IntoPy<PyObject> for collections::HashSet<K, S>
where
    K: IntoPy<PyObject> + Eq + hash::Hash,
    S: hash::BuildHasher + Default,
{
    fn into_py(self, py: Python<'_>) -> PyObject {
        new_from_iter(py, self.into_iter().map(|item| item.into_py(py)))
            .expect("Failed to create Python set from HashSet")
            .into()
    }

    #[cfg(feature = "experimental-inspect")]
    fn type_output() -> TypeInfo {
        TypeInfo::set_of(K::type_output())
    }
}

impl<'py, K, S> FromPyObject<'py> for collections::HashSet<K, S>
where
    K: FromPyObject<'py> + cmp::Eq + hash::Hash,
    S: hash::BuildHasher + Default,
{
    fn extract_bound(ob: &Bound<'py, PyAny>) -> PyResult<Self> {
        match ob.downcast::<PySet>() {
            Ok(set) => set.iter().map(|any| any.extract()).collect(),
            Err(err) => {
                if let Ok(frozen_set) = ob.downcast::<PyFrozenSet>() {
                    frozen_set.iter().map(|any| any.extract()).collect()
                } else {
                    Err(PyErr::from(err))
                }
            }
        }
    }

    #[cfg(feature = "experimental-inspect")]
    fn type_input() -> TypeInfo {
        TypeInfo::set_of(K::type_input())
    }
}

impl<K> IntoPy<PyObject> for collections::BTreeSet<K>
where
    K: IntoPy<PyObject> + cmp::Ord,
{
    fn into_py(self, py: Python<'_>) -> PyObject {
        new_from_iter(py, self.into_iter().map(|item| item.into_py(py)))
            .expect("Failed to create Python set from BTreeSet")
            .into()
    }

    #[cfg(feature = "experimental-inspect")]
    fn type_output() -> TypeInfo {
        TypeInfo::set_of(K::type_output())
    }
}

impl<'py, K> FromPyObject<'py> for collections::BTreeSet<K>
where
    K: FromPyObject<'py> + cmp::Ord,
{
    fn extract_bound(ob: &Bound<'py, PyAny>) -> PyResult<Self> {
        match ob.downcast::<PySet>() {
            Ok(set) => set.iter().map(|any| any.extract()).collect(),
            Err(err) => {
                if let Ok(frozen_set) = ob.downcast::<PyFrozenSet>() {
                    frozen_set.iter().map(|any| any.extract()).collect()
                } else {
                    Err(PyErr::from(err))
                }
            }
        }
    }

    #[cfg(feature = "experimental-inspect")]
    fn type_input() -> TypeInfo {
        TypeInfo::set_of(K::type_input())
    }
}

#[cfg(test)]
mod tests {
    use crate::types::{any::PyAnyMethods, PyFrozenSet, PySet};
    use crate::{IntoPy, PyObject, Python, ToPyObject};
    use std::collections::{BTreeSet, HashSet};

    #[test]
    fn test_extract_hashset() {
        Python::with_gil(|py| {
            let set = PySet::new_bound(py, &[1, 2, 3, 4, 5]).unwrap();
            let hash_set: HashSet<usize> = set.extract().unwrap();
            assert_eq!(hash_set, [1, 2, 3, 4, 5].iter().copied().collect());

            let set = PyFrozenSet::new_bound(py, &[1, 2, 3, 4, 5]).unwrap();
            let hash_set: HashSet<usize> = set.extract().unwrap();
            assert_eq!(hash_set, [1, 2, 3, 4, 5].iter().copied().collect());
        });
    }

    #[test]
    fn test_extract_btreeset() {
        Python::with_gil(|py| {
            let set = PySet::new_bound(py, &[1, 2, 3, 4, 5]).unwrap();
            let hash_set: BTreeSet<usize> = set.extract().unwrap();
            assert_eq!(hash_set, [1, 2, 3, 4, 5].iter().copied().collect());

            let set = PyFrozenSet::new_bound(py, &[1, 2, 3, 4, 5]).unwrap();
            let hash_set: BTreeSet<usize> = set.extract().unwrap();
            assert_eq!(hash_set, [1, 2, 3, 4, 5].iter().copied().collect());
        });
    }

    #[test]
    fn test_set_into_py() {
        Python::with_gil(|py| {
            let bt: BTreeSet<u64> = [1, 2, 3, 4, 5].iter().cloned().collect();
            let hs: HashSet<u64> = [1, 2, 3, 4, 5].iter().cloned().collect();

            let bto: PyObject = bt.clone().into_py(py);
            let hso: PyObject = hs.clone().into_py(py);

            assert_eq!(bt, bto.extract(py).unwrap());
            assert_eq!(hs, hso.extract(py).unwrap());
        });
    }

    #[test]
    fn test_set_to_object() {
        Python::with_gil(|py| {
            let bt: BTreeSet<u64> = [1, 2, 3, 4, 5].iter().cloned().collect();
            let hs: HashSet<u64> = [1, 2, 3, 4, 5].iter().cloned().collect();

            let bto: PyObject = bt.to_object(py);
            let hso: PyObject = hs.to_object(py);

            assert_eq!(bt, bto.extract(py).unwrap());
            assert_eq!(hs, hso.extract(py).unwrap());
        });
    }
}