flow-parser

JavaScript parser written in OCaml. Produces ESTree AST

Usage no npm install needed!

<script type="module">
  import flowParser from 'https://cdn.skypack.dev/flow-parser';
</script>

README

The flow-parser package

This package contains the Flow parser in its compiled-to-JavaScript form.

What is Flow

See flow.org. The code for the Flow parser lives on GitHub.

What is the Flow Parser

The Flow Parser is a JavaScript parser written in OCaml. It produces an AST that conforms to the ESTree spec and that mostly matches what esprima produces. The Flow Parser can be compiled to native code or can be compiled to JavaScript using js_of_ocaml. This npm package contains the Flow parser compiled to JavaScript.

Usage

You can use the Flow parser in your browser or in node. To use in node you can just do

require('flow-parser').parse('1+1', {});

To use in the browser, you can add

<script src="flow_parser.js"></script>

which will make the flow object available to use like so:

flow.parse('1+1', {});

Options

The second argument to flow.parse is the options object. Currently supported options:

  • all_comments (boolean, default true) - include a list of all comments from the whole program
  • comments (boolean, default true) - attach comments to AST nodes (leadingComments and trailingComments)
  • enums (boolean, default false) - enable parsing of Flow enums
  • esproposal_class_instance_fields (boolean, default false) - enable parsing of class instance fields
  • esproposal_class_static_fields (boolean, default false) - enable parsing of class static fields
  • esproposal_decorators (boolean, default false) - enable parsing of decorators
  • esproposal_export_star_as (boolean, default false) - enable parsing of export * as syntax
  • esproposal_nullish_coalescing (boolean, default false) - enable parsing of nullish coalescing (??)
  • esproposal_optional_chaining (boolean, default false) - enable parsing of optional chaining (?.)
  • tokens (boolean, default false) - include a list of all parsed tokens in a top-level tokens property
  • types (boolean, default true) - enable parsing of Flow types
  • use_strict (boolean, default false) - treat the file as strict, without needing a "use strict" directive