esdispatch

Trigger events based on esquery selectors during a traversal of a SpiderMonkey format AST.

Install

npm install --save esdispatch

Examples

var counter = 0, dispatcher = new ESDispatcher;
dispatcher.on(
  'UpdateExpression[operator="++"] > Identifier[name=i]',
  function(node, ancestors) { ++counter; }
);
dispatcher.observe(spidermonkeyAST, function() {
  counter; // 4
});

API

new ESDispatcher → ESDispatcher instance

The ESDispatcher constructor takes no arguments.

ESDispatcher::addListener(selector, listener) → void

Invoke listener whenever esdispatch walks over a node that matches selector. listener is given two arguments: the node that matched the selector, and a list containing the ancestors of that node. listener may also be an object containing an enter and, optionally, a leave function. In that case, the enter function will be called in pre-order, and the leave function will be called in post-order. Aliased as ESDispatcher::on.

ESDispatcher::once(selector, listener) → void

Adds a listener that is invoked only the first time selector matches.

ESDispatcher::observe(ast, onFinished) → void

Begin a traversal using the given SpiderMonkey AST, triggering any listeners associated with matching queries. onFinished, if given, is called with no arguments once the traversal is completed.