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Pack logtalk -- logtalk-3.97.1/library/toon/NOTES.md

This file is part of Logtalk https://logtalk.org/ SPDX-FileCopyrightText: 1998-2025 Paulo Moura <pmoura@logtalk.org> SPDX-License-Identifier: Apache-2.0

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.

toon

The toon library provides predicates for parsing and generating data in the TOON (Token-Oriented Object Notation) format. TOON is a compact, human-readable, line-oriented format that encodes the JSON data model while minimizing tokens. For more information on the TOON format, see:

https://github.com/toon-format/toon

API documentation

Open the [../../apis/library_index.html#toon](../../apis/library_index.html#toon) link in a web browser.

Loading

To load all entities in this library, load the loader.lgt file:

| ?- logtalk_load(toon(loader)).

Testing

To test this library predicates, load the tester.lgt file:

| ?- logtalk_load(toon(tester)).

Representation

TOON objects are represented using the same conventions as the json library. The representation of TOON objects and TOON pairs can be controlled using the toon/3 parametric object. The three parameters are:

  • ObjectRepresentation: curly (default) or list
  • PairRepresentation: dash (default), equal, or colon
  • StringRepresentation: atom (default), chars, or codes The toon(StringRepresentation) and toon objects use the default representations.

Objects

TOON objects are represented using curly terms by default:

{Key1-Value1, Key2-Value2, ...}

Or using lists when using list for the ObjectRepresentation parameter:

toon([Key1-Value1, Key2-Value2, ...])

Arrays

TOON arrays are represented as lists:

[Element1, Element2, ...]

Primitives

TOON primitive values are represented as follows:

  • Strings: atoms (default), chars(ListOfChars), or codes(ListOfCodes)
  • Numbers: Prolog numbers
  • Booleans: `@true and @false`
  • Null: `@null`

TOON format features

TOON is a line-oriented format with the following key features:

  • Uses indentation (2 spaces) instead of braces for objects
  • Arrays declare their length: `[N]:` for inline or `[N]{fields}:` for tabular
  • Tabular form for uniform arrays of objects with primitive values
  • Minimal quoting rules for strings
  • Three delimiters: comma (default), tab, and pipe
  • UTF-8 encoding with LF line endings
  • File extension: `.toon`, media type: text/toon

Usage examples

Parsing TOON from an atom:

| ?- toon::parse(atom('name: John\nage: 30'), Term). Term = {name-'John', age-30} yes

Generating TOON to an atom:

| ?- toon::generate(atom(Atom), {name-'John', age-30}). Atom = 'name: John\nage: 30' yes

Parsing TOON from a file:

| ?- toon::parse(file('data.toon'), Term). ...

Generating TOON to a file:

| ?- toon::generate(file('output.toon'), {name-'John', age-30}). ...

Using different representations:

| ?- toon(list, dash, atom)::parse(atom('name: John'), Term). Term = toon([name-'John']) yes