A parser only compliant with TOML v0.4.0

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2511.1.15 years ago8 years agoMinified + gzip package size for toml-j0.4 in KB


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As its name TOML-j0.4 says, this is a TOML v0.4.0 compliant parser built with PEG.js. You can customize it easily by modifying the grammar file toml.pegjs.

Live Demo


You can install it via npm install toml-j0.4, or just include the script dist/toml-browser.js in your web pages.
var toml = toml || require('toml-j0.4');

try {
    var data = toml.parse(src);
} catch (err) {
    if (err instanceof toml.SyntaxError) {
        // do something

  • toml.parse only accept one argument — data text in TOML
  • The instance of toml.SyntaxError has these properties:
* `line`: the line number
* `column`: the column number
* `offset`: the zero-based offset from the start of the text
* `message`: error message
There is no other API for now. Simple?

Known Problems

  • JavaScript does not have real integers.
All numbers are floats in JavaScript. Any integer bigger than
Number.MAX_SAFE_INTEGER (9007199254740991 < 2^63 - 1) or smaller than
Number.MIN_SAFE_INTEGER (-9007199254740991 > -(2^63 - 1)) is not safe when
being converted or used as pure integer!  Enhancement is welcome!

I suggest storing big integers in strings.
  • RFC 3339 is not the sole criterion of truth.
You can't imagine how terrible all minitue details of the standard are! So
don't expect some date-times will work anytime and anywhere, for instance,
"2015-02-29T00:00:00Z", "2015-12-25T24:00:00Z", "2015-11-10T00:60:00Z",
"2015-11-10T00:00:60Z", "2015-12-25T24:00:00+24:00",
"0000-01-01T00:00:00Z". Enhancement is welcome!


If you found bugs, welcome to send me a pull request with (only) updated test scripts/fixtures!
In order to test this package thoroughly, you have to do these first:
  1. Clone this project with git.
  2. Excute this command in the project directory: npm install

The scripts lib/parser.js and dist/toml-browser.js are generated via this command:
npm run build

Then you can test them via this command:
npm test

You can also do some benchmarks with other TOML parsers:
npm run benchmark


This package is also used by other projects: