func lookupAvoid(avoid string, r *maps.DistanceMatrixRequest) { switch avoid { case "tolls": r.Avoid = maps.AvoidTolls case "highways": r.Avoid = maps.AvoidHighways case "ferries": r.Avoid = maps.AvoidFerries case "": // ignore default: log.Fatalf("Unknown avoid restriction %s", avoid) } }