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-rw-r--r--vendor/indexmap/src/map/serde_seq.rs138
1 files changed, 138 insertions, 0 deletions
diff --git a/vendor/indexmap/src/map/serde_seq.rs b/vendor/indexmap/src/map/serde_seq.rs
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+//! Functions to serialize and deserialize an `IndexMap` as an ordered sequence.
+//!
+//! The default `serde` implementation serializes `IndexMap` as a normal map,
+//! but there is no guarantee that serialization formats will preserve the order
+//! of the key-value pairs. This module serializes `IndexMap` as a sequence of
+//! `(key, value)` elements instead, in order.
+//!
+//! This module may be used in a field attribute for derived implementations:
+//!
+//! ```
+//! # use indexmap::IndexMap;
+//! # use serde_derive::{Deserialize, Serialize};
+//! #[derive(Deserialize, Serialize)]
+//! struct Data {
+//! #[serde(with = "indexmap::map::serde_seq")]
+//! map: IndexMap<i32, u64>,
+//! // ...
+//! }
+//! ```
+
+use serde::de::{Deserialize, Deserializer, SeqAccess, Visitor};
+use serde::ser::{Serialize, Serializer};
+
+use core::fmt::{self, Formatter};
+use core::hash::{BuildHasher, Hash};
+use core::marker::PhantomData;
+
+use crate::map::Slice as MapSlice;
+use crate::set::Slice as SetSlice;
+use crate::IndexMap;
+
+/// Serializes a `map::Slice` as an ordered sequence.
+///
+/// This behaves like [`crate::map::serde_seq`] for `IndexMap`, serializing a sequence
+/// of `(key, value)` pairs, rather than as a map that might not preserve order.
+impl<K, V> Serialize for MapSlice<K, V>
+where
+ K: Serialize,
+ V: Serialize,
+{
+ fn serialize<T>(&self, serializer: T) -> Result<T::Ok, T::Error>
+ where
+ T: Serializer,
+ {
+ serializer.collect_seq(self)
+ }
+}
+
+/// Serializes a `set::Slice` as an ordered sequence.
+impl<T> Serialize for SetSlice<T>
+where
+ T: Serialize,
+{
+ fn serialize<Se>(&self, serializer: Se) -> Result<Se::Ok, Se::Error>
+ where
+ Se: Serializer,
+ {
+ serializer.collect_seq(self)
+ }
+}
+
+/// Serializes an `IndexMap` as an ordered sequence.
+///
+/// This function may be used in a field attribute for deriving `Serialize`:
+///
+/// ```
+/// # use indexmap::IndexMap;
+/// # use serde_derive::Serialize;
+/// #[derive(Serialize)]
+/// struct Data {
+/// #[serde(serialize_with = "indexmap::map::serde_seq::serialize")]
+/// map: IndexMap<i32, u64>,
+/// // ...
+/// }
+/// ```
+pub fn serialize<K, V, S, T>(map: &IndexMap<K, V, S>, serializer: T) -> Result<T::Ok, T::Error>
+where
+ K: Serialize + Hash + Eq,
+ V: Serialize,
+ S: BuildHasher,
+ T: Serializer,
+{
+ serializer.collect_seq(map)
+}
+
+/// Visitor to deserialize a *sequenced* `IndexMap`
+struct SeqVisitor<K, V, S>(PhantomData<(K, V, S)>);
+
+impl<'de, K, V, S> Visitor<'de> for SeqVisitor<K, V, S>
+where
+ K: Deserialize<'de> + Eq + Hash,
+ V: Deserialize<'de>,
+ S: Default + BuildHasher,
+{
+ type Value = IndexMap<K, V, S>;
+
+ fn expecting(&self, formatter: &mut Formatter<'_>) -> fmt::Result {
+ write!(formatter, "a sequenced map")
+ }
+
+ fn visit_seq<A>(self, mut seq: A) -> Result<Self::Value, A::Error>
+ where
+ A: SeqAccess<'de>,
+ {
+ let capacity = seq.size_hint().unwrap_or(0);
+ let mut map = IndexMap::with_capacity_and_hasher(capacity, S::default());
+
+ while let Some((key, value)) = seq.next_element()? {
+ map.insert(key, value);
+ }
+
+ Ok(map)
+ }
+}
+
+/// Deserializes an `IndexMap` from an ordered sequence.
+///
+/// This function may be used in a field attribute for deriving `Deserialize`:
+///
+/// ```
+/// # use indexmap::IndexMap;
+/// # use serde_derive::Deserialize;
+/// #[derive(Deserialize)]
+/// struct Data {
+/// #[serde(deserialize_with = "indexmap::map::serde_seq::deserialize")]
+/// map: IndexMap<i32, u64>,
+/// // ...
+/// }
+/// ```
+pub fn deserialize<'de, D, K, V, S>(deserializer: D) -> Result<IndexMap<K, V, S>, D::Error>
+where
+ D: Deserializer<'de>,
+ K: Deserialize<'de> + Eq + Hash,
+ V: Deserialize<'de>,
+ S: Default + BuildHasher,
+{
+ deserializer.deserialize_seq(SeqVisitor(PhantomData))
+}