Crate toon_format_rs 

TOON Format - Token-Oriented Object Notation

A Rust implementation of the TOON (Token-Oriented Object Notation) format. TOON is a compact, human-readable serialization format designed to minimize tokens when sending structured data to Large Language Models (LLMs).

Quick Start

use toon_format_rs::{parse, to_string, Value};

// Parse TOON string
let input = r#"id: 123
name: Alice
active: true"#;

let value = parse(input).unwrap();
assert_eq!(value.get("id").unwrap().as_i64(), Some(123));

// Serialize to TOON
let output = to_string(&value).unwrap();
assert!(output.contains("id: 123"));

Features

• Compact: 30-60% fewer tokens than JSON for uniform arrays
• Human-readable: YAML-like indentation with CSV-like tabular arrays
• Schema-aware: Explicit array lengths and field lists
• Lossless: Convert JSON → TOON → JSON without data loss
• LLM-optimized: Designed specifically for LLM prompts

Re-exports

pub use error::Error;

pub use error::Result;

pub use lexer::Lexer;

pub use lexer::Token;

pub use parser::parse;

pub use parser::Parser;

pub use serializer::to_string;

pub use serializer::to_string_pretty;

pub use serializer::Delimiter;

pub use serializer::SerializeOptions;

pub use serializer::Serializer;

pub use value::Value;

Modules

error

lexer

parser

serializer

value

Functions

json_to_toon

Converts a JSON string to TOON format

toon_to_json

Converts a TOON string to JSON format

toon_to_json_pretty

Converts a TOON string to pretty-printed JSON