code: function compareForwardSlotSegs(seg1, seg2) {
  	// put higher-pressure first
  	return seg2.forwardPressure - seg1.forwardPressure ||
  		// put segments that are closer to initial edge first (and favor ones with no coords yet)
  		(seg1.backwardCoord || 0) - (seg2.backwardCoord || 0) ||
  		// do normal sorting...
  		compareSlotSegs(seg1, seg2);
  }
docs: A cmp function for determining which forward segment to rely on more when computing coordinates.