Format Overview

TTOON has two text syntaxes:

• T-TOON: indentation-based, optimized for reading and editing by humans
• T-JSON: bracket-based, closer to JSON tooling and habits
• Shared typed value layer: both syntaxes use the same value encoding rules

T-TOON is an extension of TOON, the original format from the toon-format project. It keeps TOON's indentation-based object layout and compact tabular form, then adds explicit typed values and the companion T-JSON syntax.

Most parse APIs auto-detect the input format, so in many workflows you can choose the syntax based on readability and interoperability rather than parser configuration.

T-TOON at a Glance

T-TOON removes redundant brackets and uses indentation to express structure.

Object

name: "Alice"
age: 30
active: true

Nested Object

user:
  name: "Alice"
  address:
    city: "Taipei"

Tabular Data

[2]{name,score}:
"Alice", 95
"Bob", 87

The [N]{fields}: header declares row count and column names. This is the compact form for a list of uniform objects.

T-JSON at a Glance

T-JSON keeps JSON-like {} / [] structure, but values still use TTOON typed syntax.

Object

{"name": "Alice", "amount": 123.45m, "id": uuid(550e8400-e29b-41d4-a716-446655440000)}

Array

[1, 2, 3]

Nested

{"user": {"name": "Alice", "scores": [95, 87]}}

Typed Values at a Glance

Both syntaxes share the same 12 built-in typed value encodings:

Type	Example
null	null
bool	true
int	42
float	3.14
decimal	123.45m
string	"Alice"
date	2026-03-08
time	14:30:00
datetime	2026-03-08T14:30:00+08:00
uuid	uuid(550e8400-e29b-41d4-a716-446655440000)
hex	hex(48656C6C6F)
b64	b64(SGVsbG8=)

Three Rules to Remember

• Strings are always quoted: use "...", not bare words
• Exact decimal uses m: 123.45m is decimal, 123.45 is float
• UUID and binary use wrappers: uuid(...), hex(...), b64(...)

Which Syntax Should I Use?

Scenario	Recommended
Human-readable config, logs, or diffs	T-TOON
Large tabular datasets	T-TOON tabular
JSON-like downstream integration	T-JSON
Bracket-based nesting preferred	T-JSON
Cross-language object exchange	Either

Next Steps

• Typed Value Reference — Full type semantics, detailed syntax rules, cross-language mapping, Arrow mapping, and RDBMS correspondence
• Format Detection — Exact auto-detection rules for tjson, ttoon, and typed_unit
• T-TOON vs T-JSON — More detailed comparison between the two syntaxes