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babylon

6.9.1 • Public • Published

babylon

Babylon is a JavaScript parser used in Babel.

Travis Status Codecov Status

  • The latest ECMAScript version enabled by default (ES2017).
  • 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.

Output

Babylon generates AST according to Babel AST format. It is based on ESTree spec with the following deviations:

AST for JSX code is based on Facebook JSX AST with the addition of one node type:

  • JSXText

Example

require("babylon").parse("code", {
  // parse in strict mode and allow module declarations
  sourceType: "module",
 
  plugins: [
    // enable jsx and flow syntax
    "jsx",
    "flow"
  ]
});

Plugins

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

Install

npm i [email protected]

Version

6.9.1

License

MIT

Homepage

babeljs.io/

Last publish

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