enum_map/
serde.rs

Help
1// SPDX-FileCopyrightText: 2017 - 2023 Kamila Borowska <kamila@borowska.pw>
2// SPDX-FileCopyrightText: 2021 Bruno Corrêa Zimmermann <brunoczim@gmail.com>
3//
4// SPDX-License-Identifier: MIT OR Apache-2.0
5
6use crate::{enum_map, EnumArray, EnumMap};
7use core::fmt;
8use core::marker::PhantomData;
9use serde::de::{self, Deserialize, Deserializer, Error, MapAccess, SeqAccess};
10use serde::ser::{Serialize, SerializeTuple, Serializer};
11
12/// Requires crate feature `"serde"`
13impl<K: EnumArray<V> + Serialize, V: Serialize> Serialize for EnumMap<K, V> {
14    fn serialize<S: Serializer>(&self, serializer: S) -> Result<S::Ok, S::Error> {
15        if serializer.is_human_readable() {
16            serializer.collect_map(self)
17        } else {
18            let mut tup = serializer.serialize_tuple(self.len())?;
19            for value in self.values() {
20                tup.serialize_element(value)?;
21            }
22            tup.end()
23        }
24    }
25}
26
27/// Requires crate feature `"serde"`
28impl<'de, K, V> Deserialize<'de> for EnumMap<K, V>
29where
30    K: EnumArray<V> + EnumArray<Option<V>> + Deserialize<'de>,
31    V: Deserialize<'de>,
32{
33    fn deserialize<D: Deserializer<'de>>(deserializer: D) -> Result<Self, D::Error> {
34        if deserializer.is_human_readable() {
35            deserializer.deserialize_map(HumanReadableVisitor(PhantomData))
36        } else {
37            deserializer.deserialize_tuple(K::LENGTH, CompactVisitor(PhantomData))
38        }
39    }
40}
41
42struct HumanReadableVisitor<K, V>(PhantomData<(K, V)>);
43
44impl<'de, K, V> de::Visitor<'de> for HumanReadableVisitor<K, V>
45where
46    K: EnumArray<V> + EnumArray<Option<V>> + Deserialize<'de>,
47    V: Deserialize<'de>,
48{
49    type Value = EnumMap<K, V>;
50
51    fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
52        write!(formatter, "a map")
53    }
54
55    fn visit_map<M: MapAccess<'de>>(self, mut access: M) -> Result<Self::Value, M::Error> {
56        let mut entries = EnumMap::default();
57        while let Some((key, value)) = access.next_entry()? {
58            entries[key] = Some(value);
59        }
60        for value in entries.values() {
61            value
62                .as_ref()
63                .ok_or_else(|| M::Error::custom("key not specified"))?;
64        }
65        Ok(enum_map! { key => entries[key].take().unwrap() })
66    }
67}
68
69struct CompactVisitor<K, V>(PhantomData<(K, V)>);
70
71impl<'de, K, V> de::Visitor<'de> for CompactVisitor<K, V>
72where
73    K: EnumArray<V> + EnumArray<Option<V>> + Deserialize<'de>,
74    V: Deserialize<'de>,
75{
76    type Value = EnumMap<K, V>;
77
78    fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
79        write!(formatter, "a sequence")
80    }
81
82    fn visit_seq<M: SeqAccess<'de>>(self, mut access: M) -> Result<Self::Value, M::Error> {
83        let mut entries = EnumMap::default();
84        let len = entries.len();
85        {
86            let mut iter = entries.values_mut();
87            while let Some(place) = iter.next() {
88                *place = Some(access.next_element()?.ok_or_else(|| {
89                    M::Error::invalid_length(
90                        len - iter.len() - 1,
91                        &"a sequence with as many elements as there are variants",
92                    )
93                })?);
94            }
95        }
96        Ok(enum_map! { key => entries[key].take().unwrap() })
97    }
98}
enum_map/serde.rs

enum_map/
serde.rs
