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This file is part of Logtalk <https://logtalk.org/>
SPDX-FileCopyrightText: 1998-2026 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

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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
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`toml`
======

The `toml` library provides predicates for parsing and generating data in
the TOML format:

https://toml.io

It includes parametric objects whose parameters allow selecting the
representation for parsed TOML tables (`compound` or `curly`), TOML text
strings (`atom`, `chars`, or `codes`) and TOML pairs (`dash`, `equal`, or
`colon`).


API documentation
-----------------

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


Loading
-------

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

	| ?- logtalk_load(toml(loader)).


Testing
-------

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

	| ?- logtalk_load(toml(tester)).


Status
------

The full TOML 1.0.0 data model is covered:

- key/value assignments
- standard tables using `[table]` headers
- dotted keys
- arrays
- inline tables
- array-of-tables
- booleans
- decimal, hexadecimal, octal, and binary integers
- decimal floats plus `inf` and `nan`
- single-line and multiline basic and literal strings
- local dates, local times, local date-times, and offset date-times
- parsing and generation from files, streams, chars, codes, and atoms


Representation
--------------

The following choices of syntax have been made to represent TOML elements
as terms:

- By default, TOML tables are represented using the compound term
`toml(Pairs)`, where `Pairs` is a list using the selected pair
representation.

- Alternatively, TOML tables can be represented using curly-bracketed
terms, `{Pairs}`, where `Pairs` uses the selected pair representation.

- Arrays are represented using lists.

- Text strings can be represented as atoms, `chars(List)`, or `codes(List)`.
The default when decoding is to use atoms when using the `toml` object. To
decode text strings into lists of chars or codes, use the `toml/1` object
with the parameter bound to `chars` or `codes`.

- TOML booleans are represented by `@true` and `@false`.

- TOML special floats are represented by `@(inf)`, `@(-inf)`, and `@(nan)`.

Examples using the default `toml` object:

| TOML                            | term                                       |
| :------------------------------ | :----------------------------------------- |
| `title = "Example"`            | `toml([title-'Example'])`                  |
| `point = {x = 1, y = 2}`        | `toml([point-toml([x-1, y-2])])`           |
| `[owner]` `name = "Tom"`       | `toml([owner-toml([name-'Tom'])])`         |
| `enabled = true`                | `toml([enabled-@true])`                    |
| `limits = [1, 2, 3]`            | `toml([limits-[1,2,3]])`                   |


Examples
--------

### Parsing a TOML String

    |?- toml::parse(atom('title = "Example"\n[owner]\nname = "Tom"\n'), TOML).
    TOML = toml([title-'Example', owner-toml([name-'Tom'])]).

### Parsing with Curly Table Representation

    | ?- toml(curly,dash,atom)::parse(atom('title = "Example"\n[owner]\nname = "Tom"\n'), TOML).
    TOML = {title-'Example', owner-{name-'Tom'}}.

### Generating TOML

    | ?- toml::generate(atom(Atom), toml([title-'Example', owner-toml([name-'Tom'])])).
    Atom = 'title = "Example"\n\n[owner]\nname = "Tom"\n'.


Notes
-----

Generation is canonical and semantic. The current implementation does not
preserve comments, original quoting style, or whether a table was originally
written as an inline table or a standard table.
