Get the arguments of the current AST node

@param {Array} astList
@param {Object} context
@param {Function} callback
function (astList, context, callback) {
	var retval = new Array(astList.length);
	asyncEach(astList, function (ast, i, done) {
		run(ast, context, function (err, val) {
			if (err) {
				callback(err);
			} else {
				retval[i] = val;
				done();
			}
		});
	}, callback, null, retval);
}