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
use crate::err::{PyErr, PyResult};
use crate::ffi::{self, Py_ssize_t};
use crate::{AsPyPointer, PyAny, PyObject, Python, ToPyObject};
use std::os::raw::c_long;
#[repr(transparent)]
pub struct PySlice(PyAny);
pyobject_native_type!(
PySlice,
ffi::PySliceObject,
ffi::PySlice_Type,
#checkfunction=ffi::PySlice_Check
);
#[derive(Debug, Eq, PartialEq)]
pub struct PySliceIndices {
pub start: isize,
pub stop: isize,
pub step: isize,
pub slicelength: isize,
}
impl PySliceIndices {
pub fn new(start: isize, stop: isize, step: isize) -> PySliceIndices {
PySliceIndices {
start,
stop,
step,
slicelength: 0,
}
}
}
impl PySlice {
pub fn new(py: Python<'_>, start: isize, stop: isize, step: isize) -> &PySlice {
unsafe {
let ptr = ffi::PySlice_New(
ffi::PyLong_FromSsize_t(start),
ffi::PyLong_FromSsize_t(stop),
ffi::PyLong_FromSsize_t(step),
);
py.from_owned_ptr(ptr)
}
}
#[inline]
pub fn indices(&self, length: c_long) -> PyResult<PySliceIndices> {
unsafe {
let mut slicelength: isize = 0;
let mut start: isize = 0;
let mut stop: isize = 0;
let mut step: isize = 0;
let r = ffi::PySlice_GetIndicesEx(
self.as_ptr(),
length as Py_ssize_t,
&mut start,
&mut stop,
&mut step,
&mut slicelength,
);
if r == 0 {
Ok(PySliceIndices {
start,
stop,
step,
slicelength,
})
} else {
Err(PyErr::fetch(self.py()))
}
}
}
}
impl ToPyObject for PySliceIndices {
fn to_object(&self, py: Python<'_>) -> PyObject {
PySlice::new(py, self.start, self.stop, self.step).into()
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn test_py_slice_new() {
Python::with_gil(|py| {
let slice = PySlice::new(py, isize::MIN, isize::MAX, 1);
assert_eq!(
slice.getattr("start").unwrap().extract::<isize>().unwrap(),
isize::MIN
);
assert_eq!(
slice.getattr("stop").unwrap().extract::<isize>().unwrap(),
isize::MAX
);
assert_eq!(
slice.getattr("step").unwrap().extract::<isize>().unwrap(),
1
);
});
}
#[test]
fn test_py_slice_indices_new() {
let start = 0;
let stop = 0;
let step = 0;
assert_eq!(
PySliceIndices::new(start, stop, step),
PySliceIndices {
start,
stop,
step,
slicelength: 0
}
);
let start = 0;
let stop = 100;
let step = 10;
assert_eq!(
PySliceIndices::new(start, stop, step),
PySliceIndices {
start,
stop,
step,
slicelength: 0
}
);
let start = 0;
let stop = -10;
let step = -1;
assert_eq!(
PySliceIndices::new(start, stop, step),
PySliceIndices {
start,
stop,
step,
slicelength: 0
}
);
let start = 0;
let stop = -10;
let step = 20;
assert_eq!(
PySliceIndices::new(start, stop, step),
PySliceIndices {
start,
stop,
step,
slicelength: 0
}
);
}
}