public override FScheme.Value Evaluate(FSharpList <FScheme.Value> args) { Solid thisSolid = (Solid)((FScheme.Value.Container)args[0]).Item; Line selectLine = (Line)((FScheme.Value.Container)args[1]).Item; FaceArray faceArr = thisSolid.Faces; var thisEnum = faceArr.GetEnumerator(); SortedList <double, Autodesk.Revit.DB.Face> intersectingFaces = new SortedList <double, Autodesk.Revit.DB.Face>(); for (; thisEnum.MoveNext();) { Autodesk.Revit.DB.Face thisFace = (Autodesk.Revit.DB.Face)thisEnum.Current; IntersectionResultArray resultArray = null; SetComparisonResult resultIntersect = thisFace.Intersect(selectLine, out resultArray); if (resultIntersect != SetComparisonResult.Overlap) { continue; } bool first = true; double linePar = -1.0; foreach (IntersectionResult ir in resultArray) { double irPar = ir.Parameter; if (first == true) { linePar = irPar; first = false; } else if (irPar < linePar) { linePar = irPar; } } intersectingFaces.Add(linePar, thisFace); } var result = FSharpList <FScheme.Value> .Empty; var intersectingFacesEnum = intersectingFaces.Reverse().GetEnumerator(); for (; intersectingFacesEnum.MoveNext();) { Autodesk.Revit.DB.Face faceObj = intersectingFacesEnum.Current.Value; result = FSharpList <FScheme.Value> .Cons(FScheme.Value.NewContainer(faceObj), result); } return(FScheme.Value.NewList(result)); }