Significant diversions are expected to occur in the future such as streaming, EBNF definitions, sweet.js integration, interspatial parsing and more.
parse() parses the provided
code as an entire ECMAScript program, while
parseExpression() tries to parse a single Expression with performance in
mind. When in doubt, use
allowImportExportEverywhere: By default,
declarations can only appear at a program's top level. Setting this
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
sourceType: Indicate the mode the code should be parsed in. Can be
sourceFilename: Correlate output AST nodes with their source filename. Useful when generating code and source maps from the ASTs of multiple input files.
startLine: By default, the first line of code parsed is treated as line 1. You can provide a line number to alternatively start with. Useful for integration with other source tools.
plugins: Array containing the plugins that you want to enable.
There is now an
estreeplugin which reverts these deviations
directivesfield with Directive and DirectiveLiteral
AST for JSX code is based on Facebook JSX AST with the addition of one node type:
Babylon follows semver in most situations. The only thing to note is that some spec-compliancy bug fixes may be released under patch versions.
For example: We push a fix to early error on something like #107 - multiple default exports per file. That would be considered a bug fix even though it would cause a build to fail.
decorators(Based on an outdated version of the Decorators proposal. Will be removed in a future version of