flow-parser

The flow-parser package

This package contains the Flow parser in its JavaScript package 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 for Flow syntax. It produces an AST that conforms to the ESTree spec. This npm package contains the Flow Rust parser compiled to WASM with JavaScript bindings.

Usage

You can use the Flow parser in node:

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

Options

The second argument to parse is the options object. Common options:

Basic options

• flow ('detect' or 'all', default 'detect') - parse Flow syntax only with an @flow pragma, or always parse Flow syntax
• sourceType ('module', 'script', or 'unambiguous') - parse the file as a module, script, or infer it from the contents
• tokens (boolean, default false) - include a list of all parsed tokens in a top-level tokens property
• babel (boolean, default false) - return a Babel-shaped AST

Language features

• enableEnums (boolean, default true) - enable parsing of enums
• enableExperimentalFlowMatchSyntax (boolean, default true) - enable parsing of match expressions and match statements
• enableExperimentalComponentSyntax (boolean, default true) - enable parsing of component syntax
• assertOperator (boolean, default false) - enable parsing of the assert operator
• enableExperimentalDecorators (boolean, default true) - enable parsing of decorators

Similar packages

Other packages similar to flow-parser

acorn

Acorn is a small, fast, JavaScript-based JavaScript parser that produces an AST. It is used by various tools within the JavaScript ecosystem. Acorn is highly extensible through plugins and can handle modern JavaScript syntax. While flow-parser is specific to Flow type annotations, Acorn is more general-purpose and does not have built-in support for Flow types.

typescript-eslint-parser

typescript-eslint-parser is a parser that allows ESLint to lint TypeScript code. It converts TypeScript into an ESTree-compatible form so it can be used in the existing ESLint ecosystem. Unlike flow-parser, which is specific to Flow, typescript-eslint-parser is designed to work with TypeScript and can be used to enforce TypeScript-specific linting rules.