blah

HTML

<script src="http://code.angularjs.org/1.2.0/angular.min.js"></script>
<ul ng-app="blah" ng-controller="Ctrl">
    <!-- <li ng-repeat="item in data | filter : transform">{{ item.abc }}</li> -->
    <!-- <li ng-repeat="item in data | filter : transform track by item.def">{{ item.abc }}</li> -->
    <li ng-repeat="item in data" ng-init="transform(item)">{{ item.abc }}</li>
</ul>

JavaScript

var app = angular.module('blah', []);

function Ctrl($scope) {
    
    $scope.transform = function(item) {
        item.abc *= 2;
        return true;
    };
    
    $scope.data = [
        {abc: 123, def: 1},
        {abc: 456, def: 2},
        {abc: 789, def: 3}
    ];
    
}