JSON5

Overview

JSON5 parser and query language

JSON5 is a superset of JSON that allows comments, unquoted keys, single-quoted strings, trailing commas, and a few other ergonomic relaxations. Notch ships a JSON5 parser and a small query language for navigating the parsed tree, both in the package edu.montana.notch.json5.

What ships

  • JSON5Parser - parse a JSON5 source string into a tree of JSON5Value.
  • JSON5Value hierarchy - a sealed type tree with concrete JSON5Object, JSON5Array, JSON5String, JSON5Number (split into JSON5Integer and JSON5Decimal), JSON5Boolean, and JSON5Null cases.
  • QueryParser and QueryEngine - a tiny path expression language for pulling values out of a parsed tree.

Why JSON5

Plain JSON is strict by design. JSON5 is more pleasant to author and read by hand:

{
  // comments are allowed
  name: 'notch',
  versions: [
    1, 2, 3,         // trailing commas are fine
  ],
  unquoted: true,
}

Notch uses JSON5 anywhere it loads structured data that humans might write directly: configuration, fixtures, examples.

See also