esdispatch

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

Install

npm install --save esdispatch

Examples

``js
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.