Initial import.

PieceTable.h

@@ -0,0 +1,97 @@
+/*
+ * PieceTable.h - Alternative to GapBuffer using a piece table representation
+ */
+#ifndef KTE_PIECETABLE_H
+#define KTE_PIECETABLE_H
+
+#include <cstddef>
+#include <string>
+#include <vector>
+
+class PieceTable {
+public:
+	PieceTable();
+
+	explicit PieceTable(std::size_t initialCapacity);
+
+	PieceTable(const PieceTable &other);
+
+	PieceTable &operator=(const PieceTable &other);
+
+	PieceTable(PieceTable &&other) noexcept;
+
+	PieceTable &operator=(PieceTable &&other) noexcept;
+
+	~PieceTable();
+
+	// Public API mirrors GapBuffer
+	void Reserve(std::size_t newCapacity);
+
+	void AppendChar(char c);
+
+	void Append(const char *s, std::size_t len);
+
+	void Append(const PieceTable &other);
+
+	void PrependChar(char c);
+
+	void Prepend(const char *s, std::size_t len);
+
+	void Prepend(const PieceTable &other);
+
+	// Content management
+	void Clear();
+
+	// Accessors
+	char *Data()
+	{
+		materialize();
+		return materialized_.empty() ? nullptr : materialized_.data();
+	}
+
+
+	[[nodiscard]] const char *Data() const
+	{
+		const_cast<PieceTable *>(this)->materialize();
+		return materialized_.empty() ? nullptr : materialized_.data();
+	}
+
+
+	[[nodiscard]] std::size_t Size() const
+	{
+		return total_size_;
+	}
+
+
+	[[nodiscard]] std::size_t Capacity() const
+	{
+		// Capacity for piece table isn't directly meaningful; report materialized capacity
+		return materialized_.capacity();
+	}
+
+private:
+	enum class Source : unsigned char { Original, Add };
+
+	struct Piece {
+		Source src;
+		std::size_t start;
+		std::size_t len;
+	};
+
+	void addPieceBack(Source src, std::size_t start, std::size_t len);
+
+	void addPieceFront(Source src, std::size_t start, std::size_t len);
+
+	void materialize() const;
+
+	// Underlying storages
+	std::string original_; // unused for builder use-case, but kept for API symmetry
+	std::string add_;
+	std::vector<Piece> pieces_;
+
+	mutable std::string materialized_;
+	mutable bool dirty_     = true;
+	std::size_t total_size_ = 0;
+};
+
+#endif // KTE_PIECETABLE_H