acornjsAcorn loose parser
An error-tolerant JavaScript parser written in JavaScript.
This parser will parse any text into an ESTree syntax tree that is a reasonable approximation of what it might mean as a JavaScript program.
It will, to recover from missing brackets, treat whitespace as
significant, which has the downside that it might mis-parse a valid
but weirdly indented file. It is recommended to always try a parse
with the regular acorn parser first, and only fall back to this
parser when that one finds syntax errors.
Community
Acorn is open source software released under an MIT license.
You are welcome to report bugs or create pull requests on github.
Installation
The easiest way to install acorn-loose is from npm:
npm install acorn-loose
Alternately, you can download the source and build acorn yourself:
git clone https://github.com/acornjs/acorn.git
cd acorn
npm install
Interface
parse(input, options) takes an input string and a set of options
(the same options as
acorn
takes), and returns a syntax tree, even if the code isn't
syntactically valid. It'll insert identifier nodes with name "✖" as
placeholders in places where it can't make sense of the input. Depends
on the acorn package, because it uses the same tokenizer.
var acornLoose = require("acorn-loose");
console.log(acornLoose.parse("1 / * 4 )[2]", {ecmaVersion: 2020}));
Like the regular parser, the loose parser supports plugins. You can
take the LooseParser class exported by the module, and call its
static extend method with one or more plugins to get a customized
parser class. The class has a static parse method that acts like the
top-level parse method.
isDummy(node) takes a Node and returns true if it is a dummy node
inserted by the parser. The function performs a simple equality check on the
node's name.