title: Is it possible to prevent another $digest after $evalAsync ?
body: <p>example scenario, </p>
  
  <p><em>pseudo-code</em></p>
  
  <pre><code>scope.set_value ( user_input ) { 
  
      scope.value = user_input;
  
      // trigger digest : evaluation of several validators
  
      // execute after digest and prior to DOM rendering
      scope.$evalAsync(function() {
  
          // check if the value is valid based on 
          // validators calculated during the last digest
  
          if ( !scope.is_valid() )
              // trigger another digest with null value
              scope.value = null;
  
          else
              // NO CHANGE
              // prevent another digest... is it possible ? 
  
      });
  </code></pre>
  
  <p>Leaving aside the possible endless loop that might occur here - Is it possible to cancel the next <code>$digest</code> within <code>$evalAsync</code> ?</p>