Package Exports

estree-to-js

This package does not declare an exports field, so the exports above have been automatically detected and optimized by JSPM instead. If any package subpath is missing, it is recommended to post an issue to the original package (estree-to-js) to support the "exports" field. If that is not possible, create a JSPM override to customize the exports field for this package.

Readme

estree-to-js

Parser / JSON + visitor generator of the markdown estree spec;

Usage

npdejs API

estree-to-js interface:

var estree = require("estree-to-js");
var visitorSource = estree.fetch("es6")
  .then(estree.parse)
  .then(spec => estree.createVisitor(spec, []/*exceptions*/, "MyVisitor"))
  .catch(console.error)

Visitors

Creation of visitor:

var visitor;
visitorSource
  .then(source => eval(source + "\n" + "MyVisitor"))
  .then(MyVisitor => visitor = new MyVisitor());

Print path example

visitors have an accept(node, state, path) method and visitNodeType methods like visitVariableDeclaration(node, state, path). You can customize it to your needs, for example:

var lang = require("lively.lang"), ast = require("lively.ast");
visitor.accept = lang.fun.wrap(visitor.accept, (proceed, node, state, path) => {
  state.push(path.join(".") + " - " + node.type);
  proceed(node, state, path);
});
var state = [];
visitor.accept(ast.parse("var x = 1+3"), state, []);
console.log(state.join("\n")); // =>
                               //   - Program
                               //   body.0 - VariableDeclaration
                               //   body.0.declarations.0 - VariableDeclarator
                               //   ...

Rewriting example

var replacer = (node) => lang.obj.merge(node, {id: {type: "Identifier", name: "foo_" + node.id.name}})
var visitor = new MyVisitor();
visitor.accept = lang.fun.wrap(visitor.accept, (proceed, node, state, path) => {
  if (node.type === "VariableDeclarator") node = replacer(node);
  return proceed(node, state, path);
});
var rewritten = visitor.accept(ast.parse("var x = 1 + 3"), null, []);
ast.stringify(rewritten); // => var foo_x = 1 + 3;

command line

--out			file output file to write
--generate-json-spec	fetch and parse markdown source and generate JSON spec from it (default)
--generate-visitor	generate source code for AST visitor class
--json-spec		file to json spec. If specified it is used instead of fetching + parsing

Examples:

./bin/estree-to-js.js es6 prints JSON spec of es6 estree
./bin/estree-to-js.js es6 --generate-visitor prints JS source es6 estree visitor class

License

MIT