.. _library_toml:

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.