gistfile1.js

function decorateExpressionBindings( binding, scope, attrs ) {
    var delegate = $parse( attrs[ binding ] ).$$watchDelegate,
        actualBinding = scope[ binding ];
    
    if ( parsed.$$watchDelegate ) {
        actualBinding.$$watchDelegate = function( scope, listener, objectEquality, parsedExpression ) {
            return delegate( scope.$parent, listener, objectEquality, parsedExpression );
        };
    }
}