/babylon

A JavaScript parser

Primary LanguageJavaScriptMIT LicenseMIT

babylon

Babylon is a JavaScript parser used in Babel.

Travis Status

  • ES6 enabled by default.
  • Comment attachment.
  • Support for JSX and Flow.
  • Support for experimental language proposals.

Credits

Heavily based on acorn and acorn-jsx, thanks to the awesome work of @RReverser and @marijnh.

Significant diversions are expected to occur in the future such as streaming, EBNF definitions, sweet.js integration, interspacial parsing and more.

API

babylon.parse(code, [options])

Options

  • allowImportExportEverywhere: By default, import and export declarations can only appear at a program's top level. Setting this option to true allows them anywhere where a statement is allowed.

  • allowReturnOutsideFunction: By default, a return statement at the top level raises an error. Set this to true to accept such code.

  • allowSuperOutsideMethod TODO

  • sourceType: Indicate the mode the code should be parsed in. Can be either "script" or "module".

  • sourceFilename: Correlate output AST nodes with their source filename. Useful when generating code and source maps from the ASTs of multiple input files.

  • plugins: Array containing the plugins that you want to enable.

Example

require("babylon").parse("code", {
  // parse in strict mode and allow module declarations
  sourceType: "module",

  plugins: [
    // enable experimental async functions
    "asyncFunctions",

    // enable jsx and flow syntax
    "jsx",
    "flow"
  ]
});

Plugins

  • jsx
  • flow
  • asyncFunctions
  • classConstructorCall
  • doExpressions
  • trailingFunctionCommas
  • objectRestSpread
  • decorators
  • classProperties
  • exportExtensions
  • exponentiationOperator
  • asyncGenerators
  • functionBind
  • functionSent