added nodes.

nodes/util/ntxmapindex.h

@@ -0,0 +1,61 @@
+#ifndef NTX_MAPINDEX_H
+#define NTX_MAPINDEX_H
+
+#include <string>
+#include <unordered_map>
+#include <optional>
+#include <functional>
+#include <memory>
+
+namespace ntx
+{
+
+  /**
+   * @brief Bidirektionaler Index: String-Key → size_t Position.
+   * 
+   * Verwendet Komposition statt Vererbung.
+   * Key → Index: O(1) via unordered_map.
+   */
+  class NtxMapIndex
+  {
+
+  public:
+
+    NtxMapIndex() = default;
+
+    // --- Lookup ---
+    std::optional<size_t> indexOf(const std::string& key) const noexcept;
+    bool containsKey(const std::string& key) const noexcept;
+
+    // --- Iteration ---
+
+    /// Iteriert über alle Key→Index Paare.
+    /// Template muss im Header bleiben.
+    template <typename Fn>
+    void forEachKey(Fn&& fn) const
+    {
+      for (const auto& [key, idx] : m_keyToIndex)
+        fn(key, idx);
+    }
+
+    // --- Modification ---
+    void addKey(const std::string& key, size_t index);
+    void removeAt(size_t index);
+    bool removeKey(const std::string& key);
+    bool replaceKey(const std::string& oldKey, const std::string& newKey);
+    bool addAlias(const std::string& existingKey, const std::string& alias);
+
+    size_t size() const noexcept;
+    bool empty() const noexcept;
+    void clear() noexcept;
+
+  private:
+
+    std::unordered_map<std::string, size_t> m_keyToIndex;
+  };
+
+  using NtxMapIndexPtr = std::shared_ptr<NtxMapIndex>;
+
+} // namespace ntx
+
+#endif // NTX_MAPINDEX_H