ast-types

Defining AST node types

This feature allows users to define various types of AST nodes. The code sample shows how to define an 'Identifier' and a 'BinaryExpression' node, specifying their structure and inheritance.

const def = require('ast-types').Type.def;
def('Identifier')
  .bases('Node')
  .build('name');
def('BinaryExpression')
  .bases('Expression')
  .build('operator', 'left', 'right');

Building AST nodes

This feature enables the construction of AST nodes using predefined builders. The code sample demonstrates creating a binary expression that adds two literals.

const builders = require('ast-types').builders;
const b = builders;
const ast = b.binaryExpression('+', b.literal(1), b.literal(2));

Visiting AST nodes

This feature provides a mechanism to traverse and manipulate nodes in an AST. The code sample illustrates how to visit all identifier nodes in an AST and log their names.

const visit = require('ast-types').visit;
const ast = require('./some-ast');
visit(ast, {
  visitIdentifier(path) {
    console.log('Found an identifier:', path.node.name);
    this.traverse(path);
  }
});