srecord noeq G22MeshMapper(G22Mesh mesh1, G22Mesh mesh2) > AbstractSteppable {
  // import the important classes
  delegate Anchor, Curve to G22Mesh.
  
  // keys are the anchors from mesh1, values are the anchors from mesh2
  new Map<Anchor> anchorMap;
  
  // keys are the curves from mesh1, values are the curves from mesh2
  new Map<Curve> curveMap;
  
  bool prechecksDone;
  
  // set to the reason why when a mapping is deemed impossible
  settable O rejectedBecause;
  
  bool rejected() { ret rejectedBecause != null; }
  
  public bool step() {
    if (!prechecksDone) {
      prechecks();
      ret !rejected();
    }
  }
  
  void prechecks {
    set prechecksDone;
    sig1 = mesh1.signature();
    sig2 = mesh1.signature();
    if (!eq(sig1, sig2))
      ret with rejectedBecause(G22SignatureMismatch(mesh1, mesh2));
      
  }
}