TOON Examples

Example TOON files, one per format feature – each filename names the feature it demonstrates. All files validate against the reference implementation: valid examples decode in strict mode, invalid examples error, and every conversion pair is generated by the reference encoder and round-trip verified.

Valid Examples

Objects

• valid/objects.toon – Flat object with primitive values

  • Key-value pairs across all data types: string, number, boolean, null
  • Spec: §8

• valid/nested-objects.toon – Multi-level nested objects

  • Indentation-based nesting (2 spaces per level) instead of braces
  • Spec: §8, §12

Arrays

• valid/primitive-arrays.toon – Inline primitive arrays

  • Compact inline form [N]: item1,item2,item3 and the empty array []
  • Spec: §9.1

• valid/mixed-arrays.toon – Mixed-type array (list form)

  • One - item per element, used wherever neither inline nor tabular form applies
  • Spec: §9.4

Comments

• valid/comments.toon – Full-line # comments
  • Stripped by decoders in a lexical pre-pass, before row counting – decode-only; encoders never emit them
  • Spec: §5.1

Delimiters

• valid/pipe-delimiter.toon – Pipe delimiter (|)

  • Delimiter marker appears in both header [N|] and field list {field|...}
  • Spec: §11

• valid/tab-delimiter.toon – Tab delimiter (\t)

  • Tab character appears in both header and between fields
  • Spec: §11

• valid/delimiter-scoping.toon – Document vs active delimiter

  • Tabular row cells split only on the active delimiter; object field values follow document delimiter quoting
  • Spec: §11

Conversions

Side-by-side JSON ↔ TOON pairs, one per tabular form:

• conversions/tabular-arrays.json + conversions/tabular-arrays.toon

  • Uniform arrays of objects collapse into a table: fields declared once in the header, one row per element
  • Spec: §9.3

• conversions/nested-field-groups.json + conversions/nested-field-groups.toon

  • A uniform nested-object column folds into the header ({id,customer{name,country},total}) while rows stay flat
  • Spec: §9.3

• conversions/keyed-tabular-objects.json + conversions/keyed-tabular-objects.toon

  • Objects whose values are uniform objects become tables whose entry rows carry their own keys; the colon after the length ([3:]) marks the keyed header
  • Spec: §9.5

Invalid Examples

Files that intentionally violate TOON syntax rules and MUST error in strict mode:

• invalid/length-mismatch.toon – Array length mismatch

  • Declares [3] but provides only 2 rows
  • Spec: §14.1

• invalid/multiple-root-primitives.toon – Multiple depth-0 primitives

  • Two non-key-value lines at root depth
  • Spec: §5, §14.2

• invalid/delimiter-mismatch.toon – Header delimiter mismatch

  • Declares pipe delimiter in brackets ([N|]) but uses comma-separated fields ({a,b})
  • Spec: §6

For reference test fixtures, see the tests/ directory.