How to use

revertIndex

method

in

cc.redberry.core.parser.ParserProduct

  private static void revertIndex(ParseToken token, int index) {
    if (token instanceof ParseTokenSimpleTensor) {
      ParseTokenSimpleTensor pToken = (ParseTokenSimpleTensor) token;
      SimpleIndices indices = pToken.indices;
      for (int i = 0; i < indices.size(); i++) {
        if (indices.get(i) == index) {
          int[] inds = indices.toArray();
          inds[i] = IndicesUtils.inverseIndexState(index);
          pToken.indices = IndicesFactory.createSimple(null, inds);
          break;
        }
      }
    } else if (token.tokenType == TokenType.Product
        || token.tokenType == TokenType.Trace
        || token.tokenType == TokenType.Sum)
      for (ParseToken c : token.content)
        revertIndex(c, index);
  }
}

@Override
public ParseToken parseToken(String expression, Parser parser) {
  ParseToken node = super.parseToken(expression, parser);
  if (node == null || !parser.isAllowSameVariance())
    return node;
  TIntHashSet indices = new TIntHashSet();
  for (ParseToken c : node.content) {
    Indices free = c.getIndices().getFree();
    for (int i = 0; i < free.size(); i++) {
      int ind = free.get(i);
      if (indices.contains(ind))
        revertIndex(c, ind);
      else indices.add(ind);
    }
  }
  return node;
}