added schema node iterator

include/matador/object/schema.hpp

@@ -3,6 +3,7 @@
 
 #include "matador/object/error_code.hpp"
 #include "matador/object/schema_node.hpp"
+#include "matador/object/schema_node_iterator.hpp"
 
 #include "matador/utils/result.hpp"
 #include "matador/utils/error.hpp"
@@ -15,6 +16,8 @@ namespace matador::object {
 
 class schema {
 public:
+  typedef const_schema_node_iterator const_iterator;  /**< Shortcut for the list const iterator. */
+
   schema();
 
   template <typename Type>
@@ -36,6 +39,20 @@ public:
     return utils::ok<void>();
   }
 
+  /**
+   * Return the first schema node.
+   *
+   * @return The first schema node iterator.
+   */
+  [[nodiscard]] const_iterator begin() const;
+
+  /**
+   * Return the last schema node.
+   *
+   * @return The last schema node iterator.
+   */
+  [[nodiscard]] const_iterator end() const;
+
   [[nodiscard]] bool empty() const;
 
   [[nodiscard]] size_t size() const;

include/matador/object/schema_node.hpp

@@ -56,7 +56,8 @@ private:
 
 
 private:
-  friend schema;
+  friend class schema;
+  friend class const_schema_node_iterator;
 
   schema &schema_;
   std::unique_ptr<basic_object_info> info_;

include/matador/object/schema_node_iterator.hpp

@@ -0,0 +1,130 @@
+#ifndef SCHEMA_NODE_ITERATOR_HPP
+#define SCHEMA_NODE_ITERATOR_HPP
+
+#include "matador/object/schema_node.hpp"
+
+#include <iterator>
+
+namespace matador::object {
+
+class const_schema_node_iterator {
+public:
+  using iterator_category = std::bidirectional_iterator_tag;
+  using difference_type = std::ptrdiff_t;
+  using value_type = schema_node;
+  using pointer = value_type*;
+  using reference = value_type&;
+
+  /**
+   * Creates an empty iterator
+   */
+  const_schema_node_iterator() = default;
+
+  /**
+   * @brief Creates an iterator for a concrete type.
+   *
+   * This constructor creates an iterator for a concrete
+   * type and a concrete object.
+   *
+   * @param node The schema node of the object
+   */
+  explicit const_schema_node_iterator(std::shared_ptr<value_type> node);
+
+  /**
+   * Copy from a given const_object_view_iterator.
+   *
+   * @param x The prototype_iterator to copy from.
+   */
+  const_schema_node_iterator(const const_schema_node_iterator &x) = default;
+
+  /**
+   * Assign from a given prototype_iterator.
+   *
+   * @param x The prototype_iterator to assign from.
+   * @return The assigned prototype_iterator.
+   */
+  const_schema_node_iterator& operator=(const const_schema_node_iterator &x) = default;
+
+  ~const_schema_node_iterator() = default;
+
+  /**
+   * @brief Compares this with another iterators.
+   *
+   * Compares this with another iterators. Returns true
+   * if the iterators node prototype_type are the same.
+   *
+   * @param i The iterator to compare with.
+   * @return True if the iterators are the same.
+   */
+  bool operator==(const const_schema_node_iterator &i) const;
+
+  /**
+   * @brief Compares this with another iterators.
+   *
+   * Compares this with another iterators. Returns true
+   * if the iterators node prototype_node are not the same.
+   *
+   * @param i The iterator to compare with.
+   * @return True if the iterators are not the same.
+   */
+  bool operator!=(const const_schema_node_iterator &i) const;
+
+  /**
+   * Pre increments the iterator
+   *
+   * @return Returns iterators successor.
+   */
+  const_schema_node_iterator& operator++();
+
+  /**
+   * Post increments the iterator
+   *
+   * @return Returns iterator before incrementing.
+   */
+  const_schema_node_iterator operator++(int);
+
+  /**
+   * Pre increments the iterator
+   *
+   * @return Returns iterators predecessor.
+   */
+  const_schema_node_iterator& operator--();
+
+  /**
+   * Post decrements the iterator
+   *
+   * @return Returns iterator before decrementing.
+   */
+  const_schema_node_iterator operator--(int);
+
+  /**
+   * Returns the pointer to the node.
+   *
+   * @return The pointer to the node.
+   */
+  pointer operator->() const;
+
+  /**
+   * Returns the node.
+   *
+   * @return The iterators underlying node.
+   */
+  const reference operator*() const;
+
+  /**
+   * Returns the pointer to the node.
+   *
+   * @return The pointer to the node.
+   */
+  [[nodiscard]] pointer get() const;
+
+private:
+  void increment();
+  void decrement();
+
+private:
+  std::shared_ptr<value_type> node_;
+};
+
+}
+#endif //SCHEMA_NODE_ITERATOR_HPP