clojarse-js

A pure Javascript library for parsing Clojure code into syntax trees.

Installation

If you're using npm:

$ npm install clojarse-js

Or clone it from github:

$ git clone git@github.com:mattfenwick/clojarse-js.git

License

MIT. Please don't use it for evil.

Examples

Import it as a library from JavaScript code:

var c = require('clojarse-js');
// first the CST
console.log(JSON.stringify(c.parseCst('(^a ~b @c)'), null, 2));
// now for an AST
console.log(JSON.stringify(c.parseAst('(^a ~b @c)'), null, 2));

Or use its simple command line interface:

$ echo '(^a ~b @c)' | node main.js

Caveats

The goal is to parse a superset of Clojure's syntax. Therefore, some things which clojarse-js parses may be invalid from Clojure's point of view.

Strategy

parse CST

determine start, end of each hierarchical form and token

errors possible: first one will terminate parsing

build AST

convert the CST into an AST, throwing away some information and simplifying the structure of the tree:

• expand built-in reader macros

  • #'abc -> (var abc)
  • 'qrs -> (quote qrs)
  • @abc -> (clojure.core/deref abc)
  • ~abc -> (clojure.core/unquote abc)
  • ~@abc -> (clojure.core/unquote-splicing abc)

• fold metadata into "owner" node

Errors are not expected -- any errors should represent bugs.