ser-write-json

This crate provides a no_std friendly JSON compact serializer for serde using SerWrite as a writer and a deserializer for convenience.

This crate has been in some parts derived from work of serde-json-core and serde_json.

Usage

[dependencies]
ser-write-json = { version = "0.3", default-features = false }

Serializer

ser-write-json provides JSON serializers in 4 flavors depending on how do you want to handle types serialized with serialize_bytes method.

• to_writer - serialize bytes as number arrays,
• to_writer_hex_bytes - as HEX-encoded strings,
• to_writer_base64_bytes - as Base64 encoded strings,
• to_writer_pass_bytes - passing through bytes to a writer assuming they contain pre-serialized JSON fragments.
• to_writer_with_encoder - a custom encoder can be provided.

Custom string encoders can be implemented using ByteEncoder trait. There's an example in this repository that does exactly that.

Features:

• std enables std library,
• alloc enables alloc library,

With std or alloc features enabled additional to_string... methods are provided for convenience.

Deserializer

Unlike most JSON deserializers, a deserializer in ser-write-json expects a JSON encoded mutable slice of bytes. &str or &[u8] types are deserialized using (ZERO-COPY) references from the provided slice. The slice needs to be mutable so the decoder can unescape JSON strings and decode bytes from strings in various formats in-place.

The JSON deserializer is available in 4 flavors depending on how do you want to handle types deserialized with deserialize_bytes method from JSON strings:

• from_mut_slice - decodes bytes from regular JSON strings without checking if they are proper UTF-8 strings,
• from_mut_slice_hex_bytes - expect two hexadecimal ASCII characters per byte,
• from_mut_slice_base64_bytes - expect Base64 encoded string,
• from_mut_slice_with_decoder - a custom decoder can be provided.

Deserializer deserializes bytes in-place from a JSON array of numbers regardless of the chosen implementation.

Deserializer supports self-describing formats.

Deserializer deserializes structs from both JSON objects and arrays.

Features:

• de-any-f32 deserialization of floats to any (self-describing) type will deserialize to f32 instead of f64.

Rust Version Requirements

ser-write-json requires Rustc version 1.81 or greater.