Method flatten

core/src/main/java/org/apache/calcite/sql/SqlUtil.java:118–122

(SqlNode node)

  }

  static ArrayList<SqlNode> flatten(SqlNode node) {
    ArrayList<SqlNode> list = new ArrayList<>();
    flatten(node, list);
    return list;
  }

  /**
   * Returns the <code>n</code>th (0-based) input to a join expression.