anchor.diff:                          let commands =
                               [
                                   yield MoveTo(arr.[0])
  -
                                   for i in 1..arr.Length-1 do
                                       yield LineTo(arr.[i])
  -
  -                                yield ClosePath
                               ]
   
   
  
positive.code:                             |> maybeApp Nvg.strokeWidth width
                      else
                          Nvg.empty
  
  
                  | _ -> 
  
negative.code:                         |> renderPrimitive
                          |> maybeApp Nvg.strokeWidth width
  
  
                  | "polyline" ->
                      let points = n |> tryReadAttribute "points" |> withDefault ""
                      let width = n |> tryReadAttribute "stroke-width"
  
  