primitives/types/heap_array/
array.rs

1use std::{
2    fmt::{Debug, Display},
3    marker::PhantomData,
4    ops::{Add, Mul, Sub},
5    vec,
6};
7
8use bytemuck::{box_bytes_of, from_box_bytes, BoxBytes, Pod};
9use derive_more::derive::{AsMut, AsRef, Deref, DerefMut, IntoIterator};
10use hybrid_array::{Array, ArraySize};
11use serde::{Deserialize, Serialize};
12use typenum::{Diff, Prod, Sum, U1, U2, U3};
13
14use crate::{errors::PrimitiveError, types::Positive};
15
16/// An array on the heap that encodes its length in the type system.
17
18#[derive(Deref, DerefMut, Clone, IntoIterator, AsRef, AsMut, Eq)]
19#[into_iterator(owned, ref, ref_mut)]
20pub struct HeapArray<T: Sized, M: Positive> {
21    #[deref]
22    #[deref_mut]
23    #[as_ref(forward)]
24    #[as_mut(forward)]
25    pub(super) data: Box<[T]>,
26    #[into_iterator(ignore)]
27    // `fn() -> M` is used instead of `M` so `HeapArray<T, M>` doesn't need `M` to implement `Send
28    // + Sync` to be `Send + Sync` itself. This would be the case if `M` was used directly.
29    pub(super) _len: PhantomData<fn() -> M>,
30}
31
32// bytemuck::BoxBytes transformation for copy-less casting
33impl<T: Pod, M: Positive> HeapArray<T, M> {
34    pub fn into_box_bytes(self) -> BoxBytes {
35        box_bytes_of(self.data)
36    }
37
38    pub fn from_box_bytes(buf: BoxBytes) -> Self {
39        Self {
40            data: from_box_bytes(buf),
41            _len: PhantomData,
42        }
43    }
44}
45
46impl<T: Sized + Default, M: Positive> HeapArray<T, M> {
47    pub fn from_single_value(val: T) -> Self {
48        Self {
49            data: vec![val].into_boxed_slice(),
50            _len: PhantomData,
51        }
52    }
53}
54
55impl<T: Sized + Default, M: Positive> Default for HeapArray<T, M> {
56    fn default() -> Self {
57        Self {
58            data: (0..M::USIZE).map(|_| T::default()).collect(),
59            _len: PhantomData,
60        }
61    }
62}
63
64impl<T: Sized + Debug, M: Positive> Debug for HeapArray<T, M> {
65    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
66        f.debug_struct(format!("HeapArray<{}>", M::USIZE).as_str())
67            .field("data", &self.data)
68            .finish()
69    }
70}
71
72impl<T: Sized + Serialize, M: Positive> Serialize for HeapArray<T, M> {
73    fn serialize<S: serde::Serializer>(&self, serializer: S) -> Result<S::Ok, S::Error> {
74        self.data.serialize(serializer)
75    }
76}
77
78impl<'de, T: Sized + Deserialize<'de>, M: Positive> Deserialize<'de> for HeapArray<T, M> {
79    fn deserialize<D: serde::Deserializer<'de>>(deserializer: D) -> Result<Self, D::Error> {
80        let data = Box::<[T]>::deserialize(deserializer)?;
81
82        if data.len() != M::USIZE {
83            return Err(serde::de::Error::custom(format!(
84                "Expected array of length {}, got {}",
85                M::USIZE,
86                data.len()
87            )));
88        }
89
90        Ok(Self {
91            data,
92            _len: PhantomData,
93        })
94    }
95}
96
97impl<T: Sized, M: Positive> FromIterator<T> for HeapArray<T, M> {
98    fn from_iter<I: IntoIterator<Item = T>>(iter: I) -> Self {
99        let data = iter.into_iter().collect::<Box<_>>();
100        assert_eq!(data.len(), M::USIZE);
101        Self {
102            data,
103            _len: PhantomData,
104        }
105    }
106}
107
108// -----------------------
109// |   Split and Merge   |
110// -----------------------
111
112impl<T: Sized + Copy, M: Positive> HeapArray<T, M> {
113    pub fn split<M1, M2>(&self) -> (HeapArray<T, M1>, HeapArray<T, M2>)
114    where
115        M1: Positive,
116        M2: Positive + Add<M1, Output = M>,
117    {
118        let (m1, m2) = self.split_at(M1::USIZE);
119        (
120            HeapArray::<T, M1> {
121                data: m1.into(),
122                _len: PhantomData,
123            },
124            HeapArray::<T, M2> {
125                data: m2.into(),
126                _len: PhantomData,
127            },
128        )
129    }
130
131    pub fn split_halves<MDiv2>(&self) -> (HeapArray<T, MDiv2>, HeapArray<T, MDiv2>)
132    where
133        MDiv2: Positive + Mul<U2, Output = M>,
134    {
135        let (m1, m2) = self.split_at(MDiv2::USIZE);
136        (
137            HeapArray::<T, MDiv2> {
138                data: m1.into(),
139                _len: PhantomData,
140            },
141            HeapArray::<T, MDiv2> {
142                data: m2.into(),
143                _len: PhantomData,
144            },
145        )
146    }
147
148    pub fn merge_halves(this: Self, other: Self) -> HeapArray<T, Prod<M, U2>>
149    where
150        M: Mul<U2, Output: Positive>,
151    {
152        let mut vec = this.data.into_vec();
153        vec.extend(other.data.into_vec());
154        HeapArray::<T, Prod<M, U2>> {
155            data: vec.into_boxed_slice(),
156            _len: PhantomData,
157        }
158    }
159
160    pub fn split3<M1, M2, M3>(&self) -> (HeapArray<T, M1>, HeapArray<T, M2>, HeapArray<T, M3>)
161    where
162        M1: Positive,
163        M2: Positive + Add<M1>,
164        M3: Positive + Add<Sum<M2, M1>, Output = M>,
165    {
166        let (m1, m_rest) = self.split_at(M1::USIZE);
167        let (m2, m3) = m_rest.split_at(M2::USIZE);
168        (
169            HeapArray::<T, M1> {
170                data: m1.into(),
171                _len: PhantomData,
172            },
173            HeapArray::<T, M2> {
174                data: m2.into(),
175                _len: PhantomData,
176            },
177            HeapArray::<T, M3> {
178                data: m3.into(),
179                _len: PhantomData,
180            },
181        )
182    }
183
184    pub fn split_thirds<MDiv3>(
185        &self,
186    ) -> (
187        HeapArray<T, MDiv3>,
188        HeapArray<T, MDiv3>,
189        HeapArray<T, MDiv3>,
190    )
191    where
192        MDiv3: Positive + Mul<U3, Output = M>,
193    {
194        let (m1, m_rest) = self.split_at(MDiv3::USIZE);
195        let (m2, m3) = m_rest.split_at(MDiv3::USIZE);
196        (
197            HeapArray::<T, MDiv3> {
198                data: m1.into(),
199                _len: PhantomData,
200            },
201            HeapArray::<T, MDiv3> {
202                data: m2.into(),
203                _len: PhantomData,
204            },
205            HeapArray::<T, MDiv3> {
206                data: m3.into(),
207                _len: PhantomData,
208            },
209        )
210    }
211
212    pub fn merge_thirds(first: Self, second: Self, third: Self) -> HeapArray<T, Prod<M, U3>>
213    where
214        M: Mul<U3, Output: Positive>,
215    {
216        let mut vec = first.data.into_vec();
217        vec.extend(second.data.into_vec());
218        vec.extend(third.data.into_vec());
219        HeapArray::<T, Prod<M, U3>> {
220            data: vec.into_boxed_slice(),
221            _len: PhantomData,
222        }
223    }
224}
225
226pub struct HeapArrayTuple<T1: Sized, T2: Sized, M: Positive>(
227    pub HeapArray<T1, M>,
228    pub HeapArray<T2, M>,
229);
230
231impl<T1: Sized, T2: Sized, M: Positive> FromIterator<(T1, T2)> for HeapArrayTuple<T1, T2, M> {
232    fn from_iter<I: IntoIterator<Item = (T1, T2)>>(iter: I) -> Self {
233        let (data1, data2): (Vec<_>, Vec<_>) = iter.into_iter().unzip();
234
235        assert_eq!(data1.len(), M::USIZE);
236        assert_eq!(data2.len(), M::USIZE);
237        HeapArrayTuple(
238            HeapArray::<T1, M> {
239                data: data1.into_boxed_slice(),
240                _len: PhantomData,
241            },
242            HeapArray::<T2, M> {
243                data: data2.into_boxed_slice(),
244                _len: PhantomData,
245            },
246        )
247    }
248}
249
250impl<T: Sized, M: Positive> TryFrom<Vec<T>> for HeapArray<T, M> {
251    type Error = PrimitiveError;
252
253    fn try_from(data: Vec<T>) -> Result<Self, PrimitiveError> {
254        if data.len() == M::USIZE {
255            Ok(Self {
256                data: data.into_boxed_slice(),
257                _len: PhantomData,
258            })
259        } else {
260            Err(PrimitiveError::SizeError(M::USIZE, data.len()))
261        }
262    }
263}
264
265impl<T: Sized> From<T> for HeapArray<T, U1> {
266    fn from(element: T) -> Self {
267        Self {
268            data: Box::new([element]),
269            _len: PhantomData,
270        }
271    }
272}
273
274impl<T: Sized, M: Positive> From<HeapArray<T, M>> for Vec<T> {
275    fn from(array: HeapArray<T, M>) -> Self {
276        array.data.into_vec()
277    }
278}
279
280impl<T: Sized + Clone, M: Positive + ArraySize> From<Array<T, M>> for HeapArray<T, M> {
281    fn from(array: Array<T, M>) -> Self {
282        Self {
283            data: array.to_vec().into_boxed_slice(),
284            _len: PhantomData,
285        }
286    }
287}
288
289impl<T: Sized, M: Positive> HeapArray<T, M> {
290    pub fn split_last<N: Positive>(self) -> (HeapArray<T, Diff<M, N>>, HeapArray<T, N>)
291    where
292        M: Sub<N, Output: Positive>,
293    {
294        let mut vec = self.data.into_vec();
295        let last_n = vec.split_off(M::USIZE - N::USIZE);
296
297        (
298            HeapArray {
299                data: vec.into_boxed_slice(),
300                _len: PhantomData,
301            },
302            HeapArray {
303                data: last_n.into_boxed_slice(),
304                _len: PhantomData,
305            },
306        )
307    }
308
309    pub fn from_fn(f: impl FnMut(usize) -> T) -> Self {
310        Self {
311            data: (0..M::USIZE).map(f).collect::<Box<_>>(),
312            _len: PhantomData,
313        }
314    }
315
316    pub fn from_constant(c: T) -> Self
317    where
318        T: Copy,
319    {
320        Self {
321            data: (0..M::USIZE).map(|_| c).collect::<Box<_>>(),
322            _len: PhantomData,
323        }
324    }
325}
326
327impl<T: Sized, M: Positive> Display for HeapArray<T, M>
328where
329    T: Display,
330{
331    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
332        write!(f, "[")?;
333        for (i, item) in self.data.iter().enumerate() {
334            if i != 0 {
335                write!(f, ", ")?;
336            }
337            write!(f, "{item}")?;
338        }
339        write!(f, "]")
340    }
341}
342
343#[cfg(test)]
344pub mod tests {
345    use hybrid_array::sizes::{U2, U3, U6};
346    use typenum::{U1, U4};
347
348    use super::*;
349
350    #[test]
351    fn test_heap_array() {
352        let array = HeapArray::<_, U3>::from_fn(|i| i);
353        assert_eq!(array.into_iter().collect::<Vec<_>>(), vec![0, 1, 2]);
354    }
355
356    #[test]
357    fn test_default() {
358        let array = HeapArray::<usize, U3>::default();
359        assert_eq!(array.len(), 3);
360    }
361
362    #[test]
363    fn test_heap_array_split_last() {
364        let array = HeapArray::<_, U6>::from_fn(|i| i);
365        let (first, last) = array.split_last::<U2>();
366        assert_eq!(first.into_iter().collect::<Vec<_>>(), vec![0, 1, 2, 3]);
367        assert_eq!(last.into_iter().collect::<Vec<_>>(), vec![4, 5]);
368    }
369
370    #[test]
371    fn test_heap_array_from_array() {
372        let array = Array::<_, U3>::from_fn(|i| i);
373        let heap_array = HeapArray::<_, U3>::from(array);
374        assert_eq!(heap_array.into_iter().collect::<Vec<_>>(), vec![0, 1, 2]);
375    }
376
377    #[test]
378    fn test_heap_array_from_vec() {
379        let vec = vec![0, 1, 2];
380        let heap_array = HeapArray::<_, U3>::try_from(vec).unwrap();
381        assert_eq!(heap_array.into_iter().collect::<Vec<_>>(), vec![0, 1, 2]);
382
383        let vec = vec![0, 1];
384        let heap_array = HeapArray::<_, U3>::try_from(vec);
385        assert!(heap_array.is_err());
386    }
387
388    #[test]
389    fn test_heap_array_from_iter() {
390        let heap_array = HeapArray::<_, U3>::from_fn(|i| i);
391        assert_eq!(heap_array.into_iter().collect::<Vec<_>>(), vec![0, 1, 2]);
392    }
393
394    #[test]
395    #[should_panic]
396    fn test_heap_array_from_iter_wrong_size() {
397        HeapArray::<_, U2>::from_iter(0..3);
398    }
399
400    #[test]
401    fn test_heap_array_deserialize() {
402        let array = HeapArray::<usize, U6>::from_fn(|i| i);
403        let serialized = bincode::serialize(&array).unwrap();
404        bincode::deserialize::<HeapArray<usize, U6>>(&serialized).unwrap();
405
406        let wrong_deserialize = bincode::deserialize::<HeapArray<usize, U3>>(&serialized);
407        assert!(wrong_deserialize.is_err());
408    }
409
410    #[test]
411    fn test_heap_array_split() {
412        let array = HeapArray::<_, U6>::from_fn(|i| i);
413        let (first, second) = array.split::<U4, U2>();
414        assert_eq!(first.into_iter().collect::<Vec<_>>(), vec![0, 1, 2, 3]);
415        assert_eq!(second.into_iter().collect::<Vec<_>>(), vec![4, 5]);
416
417        let (first, second) = array.split_halves::<U3>();
418        assert_eq!(first.into_iter().collect::<Vec<_>>(), vec![0, 1, 2]);
419        assert_eq!(second.into_iter().collect::<Vec<_>>(), vec![3, 4, 5]);
420
421        // let (first, second) = array.split::<U4, U1>(); --> doesn't compile
422
423        // let (first, second) = array.split_halves::<U2>(); --> doesn't compile
424    }
425
426    #[test]
427    fn test_heap_array_split3() {
428        let array = HeapArray::<_, U6>::from_fn(|i| i);
429        let (first, second, third) = array.split3::<U3, U2, U1>();
430        assert_eq!(first.into_iter().collect::<Vec<_>>(), vec![0, 1, 2]);
431        assert_eq!(second.into_iter().collect::<Vec<_>>(), vec![3, 4]);
432        assert_eq!(third.into_iter().collect::<Vec<_>>(), vec![5]);
433
434        let (first, second, third) = array.split_thirds::<U2>();
435        assert_eq!(first.into_iter().collect::<Vec<_>>(), vec![0, 1]);
436        assert_eq!(second.into_iter().collect::<Vec<_>>(), vec![2, 3]);
437        assert_eq!(third.into_iter().collect::<Vec<_>>(), vec![4, 5]);
438
439        // let (a1, a2, a3) = array.split3::<U3, U2, U2>(); // doesn't compile
440
441        // let (a1, a2, a3) = array.split_thirds::<U2>(); // doesn't compile
442    }
443}
primitives/types/heap_array/array.rs

primitives/types/heap_array/
array.rs
