Add context_deserialize impl

Cargo.toml

@@ -10,6 +10,11 @@ documentation = "https://docs.rs/ssz_types"
 keywords = ["ethereum"]
 categories = ["cryptography::cryptocurrencies"]
 
+[features]
+default = ["ring"]
+ring = ["tree_hash/ring"]
+context_deserialize = ["dep:context_deserialize"]
+
 [dependencies]
 tree_hash = { version = "0.11.0", default-features = false }
 ethereum_serde_utils = "0.8.0"
@@ -20,16 +25,13 @@ typenum = "1.12.0"
 smallvec = "1.8.0"
 arbitrary = { version = "1.0", features = ["derive"], optional = true }
 itertools = "0.14.0"
+context_deserialize = { version = "0.1.0", optional = true }
 
 [dev-dependencies]
 criterion = "0.7.0"
 serde_json = "1.0.0"
 tree_hash_derive = "0.11.0"
 
-[features]
-default = ["ring"]
-ring = ["tree_hash/ring"]
-
 [[bench]]
 harness = false
 name = "encode_decode"

src/context_deserialize.rs

@@ -0,0 +1,18 @@
+use crate::{typenum::Unsigned, FixedVector};
+use context_deserialize::ContextDeserialize;
+use serde::de::{Deserializer, Error};
+
+impl<'de, C, T, N> ContextDeserialize<'de, C> for FixedVector<T, N>
+where
+    T: ContextDeserialize<'de, C>,
+    N: Unsigned,
+    C: Clone,
+{
+    fn context_deserialize<D>(deserializer: D, context: C) -> Result<Self, D::Error>
+    where
+        D: Deserializer<'de>,
+    {
+        let vec = Vec::<T>::context_deserialize(deserializer, context)?;
+        FixedVector::new(vec).map_err(|e| D::Error::custom(format!("{:?}", e)))
+    }
+}

src/lib.rs

@@ -43,6 +43,9 @@ pub mod serde_utils;
 mod tree_hash;
 mod variable_list;
 
+#[cfg(feature = "context_deserialize")]
+mod context_deserialize;
+
 pub use fixed_vector::FixedVector;
 pub use ssz::{BitList, BitVector, Bitfield};
 pub use typenum;