#serde-json #json #serde

no-std serde-json-core-fmt

serde-json for no_std programs

1 unstable release

0.1.1 Apr 10, 2021
0.1.0 Apr 7, 2021

#321 in No standard library

MIT/Apache

70KB
2K SLoC

Forked from serde-json-core, removed heapless dependency and changed to using core::fmt::Formatter

Usage

struct AnyStruct {}

impl core::fmt::Display for AnyStruct {
    fn fmt(&self, f: &mut core::fmt::Formatter) -> core::fmt::Result {
        serde_json_core_fmt::to_fmt(f, self)
    }
}

lib.rs:

serde-json for no_std programs

This version of serde-json is aimed at applications that run on resource constrained devices.

Current features

  • The error type is a simple C like enum (less overhead, smaller memory footprint)
  • (De)serialization doesn't require memory allocations
  • Deserialization of integers doesn't go through u64; instead the string is directly parsed into the requested integer type. This avoids pulling in KBs of compiler intrinsics when targeting a non 64-bit architecture.
  • Supports deserialization of:
    • bool
    • Integers
    • str (This is a zero copy operation.) (*)
    • Option
    • Arrays
    • Tuples
    • Structs
    • C like enums
  • Supports serialization (compact format only) of:
    • bool
    • Integers
    • str (**)
    • Option
    • Arrays
    • Tuples
    • Structs
    • C like enums

(*) Deserialization of strings ignores escaped sequences. Escaped sequences might be supported in the future using a different Serializer as this operation is not zero copy.

(**) Serialization of strings doesn't escape stuff. This simply has not been implemented yet.

Planned features

  • (De)serialization from / into IO objects once core::io::{Read,Write} becomes a thing.

Non-features

This is explicitly out of scope

  • Anything that involves dynamic memory allocation
    • Like the dynamic Value type

Minimum Supported Rust Version (MSRV)

This crate is guaranteed to compile on stable Rust 1.40.0 and up. It might compile with older versions but that may change in any new patch release.

Dependencies

~145–405KB