hybrid_array/
serde.rs

1//! Support for serializing and deserializing `Array` using `serde`.
2
3use crate::{Array, ArraySize};
4use core::{fmt, marker::PhantomData};
5use serde::{
6    de::{self, Deserialize, Deserializer, SeqAccess, Visitor},
7    ser::{Serialize, SerializeTuple, Serializer},
8};
9
10impl<'de, T, U> Deserialize<'de> for Array<T, U>
11where
12    T: Deserialize<'de>,
13    U: ArraySize,
14{
15    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
16    where
17        D: Deserializer<'de>,
18        T: Deserialize<'de>,
19    {
20        struct ArrayVisitor<T> {
21            element: PhantomData<T>,
22        }
23
24        impl<'de, T, U> Visitor<'de> for ArrayVisitor<Array<T, U>>
25        where
26            T: Deserialize<'de>,
27            U: ArraySize,
28        {
29            type Value = Array<T, U>;
30
31            fn expecting(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
32                write!(formatter, "an array of length {}", U::USIZE)
33            }
34
35            fn visit_seq<A>(self, mut seq: A) -> Result<Array<T, U>, A::Error>
36            where
37                A: SeqAccess<'de>,
38            {
39                Array::<T, U>::try_from_fn(|i| {
40                    seq.next_element()?
41                        .ok_or_else(|| de::Error::invalid_length(i, &self))
42                })
43            }
44        }
45
46        let visitor = ArrayVisitor {
47            element: PhantomData,
48        };
49
50        deserializer.deserialize_tuple(U::USIZE, visitor)
51    }
52}
53
54impl<T, U> Serialize for Array<T, U>
55where
56    T: Serialize,
57    U: ArraySize,
58{
59    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
60    where
61        S: Serializer,
62    {
63        let mut seq = serializer.serialize_tuple(U::USIZE)?;
64
65        for elem in self {
66            seq.serialize_element(elem)?;
67        }
68
69        seq.end()
70    }
71}
72
73#[cfg(test)]
74mod tests {
75    use crate::{Array, sizes::U3};
76    type A = Array<u8, U3>;
77
78    #[test]
79    #[cfg(feature = "alloc")]
80    fn expecting() {
81        use alloc::string::ToString;
82        let err = serde_json::from_str::<A>("true").unwrap_err();
83        assert!(err.to_string().contains("expected an array of length 3"));
84    }
85
86    #[test]
87    fn round_trip() {
88        let example: A = Array([1, 2, 3]);
89        let s = serde_json::to_string(&example).unwrap();
90        let deserialized: A = serde_json::from_str(&s).unwrap();
91        assert_eq!(example, deserialized);
92    }
93}
hybrid_array/serde.rs

hybrid_array/
serde.rs
