anchor.diff:  
     int GetSize() {
       switch (type) {
  -      case "float":
  +      case VarTypeFloat:
           return 1;
  -      case "vec2":
  +      case VarTypeVec2:
           return 2;
  -      case "vec3":
  +      case VarTypeVec3:
           return 3;
  -      case "vec4":
  +      case VarTypeVec4:
           return 4;
         default:
           assert(false);
  
positive.code: const String vNormal = "vNormal";
  const String vVertexPosition = "vVertexPosition";
  const String vCenter = "vCenter";
  const String vPositionFromLight = "vPositionFromLight";
  
  // ===========================================================
  
negative.code: 
    bool IsScalarTypeFloat() {
      switch (type) {
        case VarTypeFloat:
        case VarTypeVec2:
        case VarTypeVec3:
        case VarTypeVec4:
          return true;
        default:
          return false;
  