Strings Initial

Allocators/CMakeLists.txt

@@ -3,7 +3,7 @@ cmake_minimum_required(VERSION 3.2)
 
 set(CMAKE_CXX_STANDARD 23)
 
-project(Allocator)
+project(Allocators)
 
 ### ---------------------- Static Library  ---------------------  ###
 file(GLOB SOURCES "./private/*.cpp")

CMakeLists.txt

@@ -15,3 +15,4 @@ add_subdirectory(Utils)
 add_subdirectory(Containers)
 add_subdirectory(Math)
 add_subdirectory(Allocators)
+add_subdirectory(Strings)

Strings/CMakeLists.txt

@@ -0,0 +1,22 @@
+
+cmake_minimum_required(VERSION 3.2)
+
+set(CMAKE_CXX_STANDARD 23)
+
+project(Strings)
+
+### ---------------------- Static Library  ---------------------  ###
+file(GLOB SOURCES "./private/*.cpp")
+file(GLOB HEADERS "./public/*.hpp")
+add_library(${PROJECT_NAME} STATIC ${SOURCES} ${HEADERS})
+target_include_directories(${PROJECT_NAME} PUBLIC ./public/)
+target_link_libraries(${PROJECT_NAME} PUBLIC Allocators Containers)
+
+### -------------------------- Tests  --------------------------  ###
+enable_testing()
+file(GLOB TEST_SOURCES "./tests/*.cpp")
+add_executable(${PROJECT_NAME}Tests ${TEST_SOURCES})
+target_link_libraries(${PROJECT_NAME}Tests  ${PROJECT_NAME} Utils)
+add_test(NAME ${PROJECT_NAME}Tests COMMAND ${PROJECT_NAME}Tests)
+
+install(TARGETS ${PROJECT_NAME} LIBRARY DESTINATION ${CMAKE_INSTALL_PREFIX}/${PROJECT_NAME}/lib)

Strings/private/Logging.cpp

@@ -0,0 +1,69 @@
+
+#include "Logging.hpp"
+#include "Allocators.hpp"
+#include "TextEditor.hpp"
+
+#include <cstdio>
+
+namespace tp {
+
+	Logger* gLogger = nullptr;
+
+	ualni Logger::Report::getLineCount() const {
+		return (ualni)(mLineOffsets.size() - 1);
+	}
+
+	String Logger::Report::getString() const {
+		return mData;
+	}
+
+	void Logger::Report::calcLineCount() {
+		Input input = { mData.raw(), (ualni) mData.size() };
+		input.getLineOffsets(mLineOffsets);
+	}
+
+	Logger::Report::Report() {
+		mData = " - ";
+	}
+
+	Logger::Report::Report(const String& text) : mData(text) {
+		calcLineCount();
+	}
+
+	Logger::Report::Report(const String& text, Type type) : mType(type), mData(text) {
+		calcLineCount();
+	}
+
+	void Logger::write(const String& in, bool post, Report::Type type) {
+		StringTemplate copy = in;
+		copy.capture();
+		mBuff.pushBack(Report(copy, type));
+
+		mLineCount += mBuff.last()->data.getLineCount();
+
+		if (!mCursor) {
+			mCursor = mBuff.last();
+		}
+
+		if (post) {
+			printf("%s", in.raw());
+		}
+	}
+
+	String Logger::read() {
+		if (!mCursor) return {};
+    const Report& out = mCursor->data;
+    mCursor = mCursor->next;
+    return out.getString();
+	}
+
+	void Logger::initializeGlobal() {
+		DEBUG_ASSERT(!gLogger)
+		gLogger = new Logger();
+	}
+
+	void Logger::deinitializeGlobal() {
+		DEBUG_ASSERT(gLogger)
+		delete gLogger;
+	}
+}

Strings/private/Strings.cpp

@@ -0,0 +1,24 @@
+
+#include "Strings.hpp"
+#include "Allocators.hpp"
+#include "Logging.hpp"
+
+using namespace tp;
+
+bool initialize(const ModuleManifest*) {
+	Logger::initializeGlobal();
+	return true;
+}
+
+void deinitialize(const ModuleManifest*) {
+	Logger::deinitializeGlobal();
+}
+
+static tp::ModuleManifest* sModuleDependencies[] = {
+	&tp::gModuleContainers,
+	&tp::gModuleAllocators,
+	&tp::gModuleUtils,
+	nullptr
+};
+
+ModuleManifest tp::gModuleStrings = ModuleManifest("Strings", initialize, deinitialize, sModuleDependencies);

Strings/private/TextEditor.cpp

@@ -0,0 +1,554 @@
+
+#include "TextEditor.hpp"
+
+using namespace tp;
+using namespace str;
+
+bool tp::str::PiecesDS::Node::mInsertionOperation = false;
+
+bool tp::str::isNewLineChar(Char character) {
+	return (character == '\n') || (character == '\r');
+}
+
+void Input::getLineOffsets(Buffer<Index>& out) {
+	halni lines = 0;
+	for (auto idx : Range(mLen)) {
+		if (isNewLineChar(mInput[idx])) {
+			lines++;
+		}
+	}
+	out.reserve(lines + 2); // plust start and end offsets
+	lines = 0;
+	for (auto idx : Range(mLen)) {
+		if (isNewLineChar(mInput[idx])) {
+			out[lines + 1] = Index(idx + 1);
+			lines++;
+		}
+	}
+	out[0] = 0;
+	out[lines + 1] = mLen;
+}
+
+ // ---------------------- Pointer ---------------------- // 
+
+Pointer::Pointer() { 
+	mCol = 0; mLine = 0; 
+}
+
+Pointer::Pointer(LineId aLine, ColumnId aCol) {
+	mLine = aLine;
+	mCol = aCol;
+}
+
+Pointer::Pointer(const Input& aInput) {
+	halni lines = 0;
+	halni col = 0;
+	for (auto idx : Range(aInput.mLen)) {
+		if (isNewLineChar(aInput.mInput[idx])) {
+			lines++;
+			col = 0;
+		}
+		else {
+			col++;
+		}
+	}
+	mLine = lines;
+	mCol = col;
+}
+
+void Pointer::operator+=(Char achar) {
+	if (isNewLineChar(achar)) {
+		mLine += 1;
+		mCol = 0;
+	}
+	else {
+		mCol += 1;
+	}
+}
+
+void Pointer::operator+=(const Pointer& ap) {
+	*this = operator+(ap);
+}
+
+Pointer Pointer::operator-(const Pointer in) const {
+	if (mLine == in.mLine) {
+		return { 0, mCol - in.mCol };
+	}
+	return { mLine - in.mLine, mCol };
+}
+
+Pointer Pointer::operator+(const Pointer& ap) const {
+	if (ap.mLine == 0) {
+		return { mLine, mCol + ap.mCol };
+	}
+	return { mLine + ap.mLine, ap.mCol };
+}
+
+bool Pointer::operator==(const Pointer& in) const {
+	return in.mCol == mCol && in.mLine == mLine;
+}
+
+bool Pointer::operator>(const Pointer& in) const {
+	if (mLine > in.mLine) {
+		return true;
+	}
+	else if (mLine < in.mLine) {
+		return false;
+	}
+
+	return mCol > in.mCol;
+}
+
+bool Pointer::operator>=(const Pointer& in) const {
+	return operator>(in) || in == *this;
+}
+
+Pointer Piece::diffPtr() const {
+	return mEnd - mStart;
+}
+
+LineId Piece::nLines() const {
+	return { mEnd.mLine - mStart.mLine };
+}
+
+// ---------------------- Add Buff ---------------------- // 
+
+AddBuff::AddBuff() {
+	Input input = { "", 0 };
+	Buffer<Index> lineoffsets;
+	input.getLineOffsets(lineoffsets);
+	mLineOffsets.append(lineoffsets.mBuff(), (Index)lineoffsets.length());
+}
+
+void AddBuff::append(Input aInput) {
+
+	// TODO : errors here
+
+	Buffer<Index> lineoffsets;
+	aInput.getLineOffsets(lineoffsets);
+
+	if (lineoffsets.length() == 2) {
+		mLineOffsets[mLineOffsets.len() - 1] += lineoffsets[1] - lineoffsets[0];
+	}
+	else {
+
+		auto last_line_offset = mLineOffsets[mLineOffsets.len() - 1];
+
+		// offset last line ptr
+		mLineOffsets[mLineOffsets.len() - 1] += lineoffsets[1];
+
+		// offset all lines by mLineOffsets.mLast ptr
+		for (auto offset : lineoffsets) {
+			offset.data() += last_line_offset;
+		}
+
+		mLineOffsets.append(&lineoffsets[2], (Index)(lineoffsets.length() - 2));
+	}
+
+	mBuff.append(aInput.mInput, aInput.mLen);
+}
+
+Pointer AddBuff::endPtr() {
+	return { mLineOffsets.len() - 2, mLineOffsets[mLineOffsets.len() - 1] - mLineOffsets[mLineOffsets.len() - 2] };
+}
+
+// ---------------------- Orig Buff ---------------------- // 
+
+OrigBuff::OrigBuff(Input aOriginal) {
+	mOriginal = aOriginal;
+	mOriginal.getLineOffsets(mLineOffsets);
+
+	mPtrStart = { 0, 0 };
+	mPtrEnd = mOriginal;
+}
+
+void OrigBuff::makeOwnOriginalInput() {
+	if (mOwnsInput) {
+		return;
+	}
+
+	auto input_copy = new Char[mOriginal.mLen + 1];
+	DEBUG_ASSERT(sizeof(Char) == sizeof(uint1));
+	memcp(input_copy, mOriginal.mInput, mOriginal.mLen);
+	input_copy[mOriginal.mLen] = '\0';
+	mOriginal.mInput = input_copy;
+	mOwnsInput = true;
+}
+
+OrigBuff::~OrigBuff() {
+	if (mOwnsInput) {
+		delete[] mOriginal.mInput;
+	}
+}
+
+// ---------------------- Editor ---------------------- // 
+
+PieceCrs TextEditor::findPiece(Pointer ptr) const {
+	PieceCrs out;
+	if (!mPieces.nPieces()) { 
+		return out; 
+	}
+
+	if (mPieces.ptrSum() == ptr) {
+		out.piece = mPieces.maxNode(mPieces.head());
+	} else {
+		out.piece = mPieces.find(ptr);
+	}
+
+	DBG_BREAK(!out.piece);
+	out.piece_ptr = out.piece->getFindKey();
+	out.ptr = ptr;
+	out.offset = out.ptr - out.piece_ptr;
+	return out;
+}
+
+void TextEditor::clampPtr(Pointer& ptr) const {
+	if (!mPieces.nPieces()) {
+		ptr = { 0, 0 };
+		return;
+	}
+
+	CLAMP(ptr.mLine, 0, mNLines());
+
+	auto crs = findPiece(Pointer{ ptr.mLine, 0 });
+	Index line_len = getPieceLineLen(crs.piece->mPiece, crs.offset.mLine);
+
+	auto next_piece_ptr = nextPiecePtr(crs.piece, crs.piece_ptr);
+	auto piece = crs.piece;
+	while (piece->mNext && ptr.mLine == next_piece_ptr.mLine) {
+		piece = piece->mNext;
+		next_piece_ptr = nextPiecePtr(piece, next_piece_ptr);
+		line_len += getPieceLineLen(piece->mPiece, 0);
+	}
+
+	if (ptr.mLine != mNLines()) {
+		line_len -= 1;
+	}
+
+	CLAMP(ptr.mCol, 0, line_len);
+}
+
+void TextEditor::setCursor(Pointer ptr) {
+	clampPtr(ptr);
+	mCursor = ptr;
+}
+
+void TextEditor::setCursorEnd(Pointer ptr) {
+	clampPtr(ptr);
+	mCursorEnd = ptr;
+	mCursor = mCursorEnd;
+}
+
+const Char* TextEditor::getPieceLine(const Piece* piece, LineId offset) const {
+	const Char* buff;
+	if (piece->mAddedBuff) {
+		if (offset == 0) {
+			buff = &mAddBuff.mBuff[mAddBuff.mLineOffsets[piece->mStart.mLine]] + piece->mStart.mCol;
+		}
+		else if (offset > piece->nLines()) {
+			buff = &mAddBuff.mBuff[mAddBuff.mLineOffsets[piece->mEnd.mLine]] + piece->mEnd.mCol;
+		}
+		else {
+			buff = &mAddBuff.mBuff[mAddBuff.mLineOffsets[piece->mStart.mLine + offset]];
+		}
+	}
+	else {
+		if (offset == 0) {
+			buff = &mOrigBuff.mOriginal.mInput[mOrigBuff.mLineOffsets[piece->mStart.mLine]] + piece->mStart.mCol;
+		}
+		else if (offset > piece->nLines()) {
+			buff = &mOrigBuff.mOriginal.mInput[mOrigBuff.mLineOffsets[piece->mEnd.mLine]] + piece->mEnd.mCol;
+		}
+		else {
+			buff = &mOrigBuff.mOriginal.mInput[mOrigBuff.mLineOffsets[piece->mStart.mLine + offset]];
+		}
+	}
+	return buff;
+}
+
+const Char* TextEditor::getBuffLine(const Piece* piece, LineId offset) const {
+	const Char* buff;
+	if (piece->mAddedBuff) {
+		buff = &mAddBuff.mBuff[mAddBuff.mLineOffsets[piece->mStart.mLine + offset]];
+	}
+	else {
+		buff = &mOrigBuff.mOriginal.mInput[mOrigBuff.mLineOffsets[piece->mStart.mLine + offset]];
+	}
+	return buff;
+}
+
+Pointer TextEditor::prevPiecePtr(PiecesDS::Node* piece_node, Pointer aPtr) const {
+	if (!piece_node->mPrev) {
+		return { 0, 0 };
+	}
+
+	return piece_node->mPrev->getFindKey();
+}
+
+Pointer TextEditor::nextPiecePtr(PiecesDS::Node* aPiece, Pointer aPtr) const {
+	if (!aPiece) return { -1, -1 };
+
+	if (aPiece->mNext) {
+		return aPiece->mNext->getFindKey();
+	}
+	return aPiece->getFindKey() + aPiece->mDiff;
+}
+
+LineId TextEditor::getPieceLineLen(Piece* aPiece, LineId line) const {
+	return LineId(getPieceLine(aPiece, line + 1) - getPieceLine(aPiece, line));
+}
+
+TextEditor::TextEditor(Input original) : mOrigBuff(original) {
+	DEBUG_ASSERT(original.mLen);
+	auto new_node = mPieces.insertAfter(0, { false, mOrigBuff.mPtrStart, mOrigBuff.mPtrEnd });
+	mPieces.pushUndoPoint();
+}
+
+TextEditor::TextEditor() : mOrigBuff({ 0, 0 }) {
+}
+
+Index TextEditor::mNLines() const {
+	return mPieces.ptrSum().mLine;
+}
+
+Pointer TextEditor::getCursor() const {
+	return mCursor;
+}
+
+Pointer TextEditor::getCursorEnd() const {
+	return mCursorEnd;
+}
+
+void TextEditor::insert(Input aInput) {
+	// handle selectiom
+	remove(true);
+
+	// save input to addbuff
+	auto start_ref = mAddBuff.endPtr();
+	mAddBuff.append(aInput);
+	auto end_ref = mAddBuff.endPtr();
+	auto input_diff = end_ref - start_ref;
+
+	PiecesDS::Node* prev_node = nullptr;
+	PiecesDS::Node* new_node = nullptr;
+
+	auto crs = findPiece(mCursor);
+
+	if (crs.piece && crs.piece->mPrev && crs.offset == Pointer{ 0, 0 }) {
+		crs.piece_ptr = prevPiecePtr(crs.piece, crs.piece_ptr);
+		crs.offset = crs.ptr - crs.piece_ptr;
+		crs.piece = crs.piece->mPrev;
+	}
+
+	if (crs.piece) {
+		if (crs.ptr == crs.piece_ptr) { // start
+			prev_node = crs.piece->mPrev;
+		}
+		else if (crs.offset == crs.piece->mPiece->diffPtr()) { // end
+			if (mLastInsertionCrs == crs.ptr && crs.piece->mPiece->mAddedBuff && crs.piece->mPiece->mEnd == start_ref) {
+				crs.piece->mPiece->mEnd += input_diff;
+				mPieces.update_cache(crs.piece);
+				goto END;
+			}
+			else {
+				prev_node = crs.piece;
+			}
+		}
+		else { // middle
+			prev_node = splitPiece(crs.piece, crs.offset);
+		}
+	}
+
+	// create the new node
+	new_node = mPieces.insertAfter(prev_node, { true, start_ref, end_ref });
+
+	END:
+	mCursor = mCursor + input_diff;
+	mCursorEnd = mCursor;
+	mLastInsertionCrs = mCursor;
+	mPieces.pushUndoPoint();
+}
+
+PiecesDS::Node* TextEditor::splitPiece(PiecesDS::Node* piece, Pointer split_ptr) {
+	auto span = piece->mPiece->diffPtr();
+
+	if (span == split_ptr || split_ptr == Pointer{ 0, 0 }) {
+		return nullptr;
+	}
+
+	// save temp data
+	auto end_ptr = piece->mPiece->mEnd;
+	auto left_piece = Piece{ piece->mPiece->mAddedBuff, piece->mPiece->mStart, piece->mPiece->mStart + split_ptr };
+	auto left_node = mPieces.insertAfter(piece->mPrev, left_piece);
+
+	// create right half
+	auto right_node = mPieces.insertAfter(left_node, { left_node->mPiece->mAddedBuff, left_node->mPiece->mEnd, end_ptr });
+
+	auto line_len = halni(getBuffLine(right_node->mPiece, 1) - getBuffLine(right_node->mPiece, 0));
+	if (line_len == right_node->mPiece->mStart.mCol) {
+		DBG_BREAK(1);
+		right_node->mPiece->mStart = { right_node->mPiece->mStart.mLine + 1, 0 };
+	}
+
+	// remove current node
+	mPieces.remove(right_node->mNext);
+
+	return left_node;
+}
+
+void TextEditor::remove(bool only_selection, Dir dir, DirUnit unit) {
+	if (!mPieces.nPieces()) {
+		return;
+	}
+
+	if (mCursor == mCursorEnd) {
+		if (only_selection) {
+			return;
+		}
+
+		if (dir == LEFT) {
+			if (mCursor == Pointer(0, 0)) {
+				return;
+			}
+
+			PieceCrs crs;
+			if (mCursor.mCol == nullptr) {
+				auto new_ptr = Pointer{ mCursor.mLine - 1, ENV_HALNI_MAX };
+				clampPtr(new_ptr);
+				crs = findPiece(new_ptr);
+				//crs = findPiece({ crs.ptr.mLine, crs.ptr.mCol - 1 });
+			}
+			else {
+				crs = findPiece({ mCursor.mLine, mCursor.mCol - 1 });
+			}
+
+			mCursorEnd = mCursor;
+			mCursor = crs.ptr;
+		}
+		else if (dir == RIGHT) {
+			auto crs = findPiece(Pointer{ mCursor.mLine, mCursor.mCol + 1 });
+			mCursorEnd = mCursor;
+			mCursor = crs.ptr;
+
+			if (mCursor == mCursorEnd) {
+				return;
+			}
+		}
+		else {
+			return;
+		}
+	}
+
+	if (mCursor > mCursorEnd) {
+		swap(mCursor, mCursorEnd);
+	}
+
+	auto crs = findPiece(mCursor);
+		
+	// first and last pieces to be deleted
+	PiecesDS::Node* del_start = nullptr, *del_end = nullptr;
+
+	// find left
+	if (crs.offset == Pointer{ 0, 0 }) {
+		del_start = crs.piece;
+	}
+	else if (crs.piece->mPiece->diffPtr() == crs.offset) {
+		del_start = crs.piece->mNext;
+	}
+	else {
+		del_start = splitPiece(crs.piece, crs.offset)->mNext;
+	}
+	
+	auto crs_end = findPiece(mCursorEnd);
+
+	// find right
+	if (crs_end.offset == Pointer{ 0, 0 }) {
+		del_end = crs_end.piece->mPrev;
+	}
+	else if (crs_end.piece->mPiece->diffPtr() == crs_end.offset) {
+		del_end = crs_end.piece;
+	}
+	else {
+		bool intersect = crs_end.piece == del_start;
+		del_end = splitPiece(crs_end.piece, crs_end.offset);
+		if (intersect) {
+			del_start = del_end;
+		}
+	}
+
+	DEBUG_ASSERT(del_start && del_end);
+	auto end_piece = del_end->mNext ? del_end->mNext->mPiece : nullptr;
+
+	while (del_start && del_start->mPiece != end_piece) {
+		auto del = del_start;
+
+		// del_start will be reused by the avl-tree after deletion otherwise
+		// works as we go from left to right
+		if (!del_start->mNext || del_start->mHeight <= del_start->mNext->mHeight) {
+			del_start = del_start->mNext;
+		}
+
+		mPieces.remove(del);
+	}
+	mCursorEnd = mCursor;
+
+	mPieces.pushUndoPoint();
+}
+
+void TextEditor::undo() {
+	mPieces.undo();
+}
+
+void TextEditor::redo() {
+	mPieces.redo();
+}
+
+TextEditor::~TextEditor() {
+}
+
+// ------------------------------ ITERATOR ------------------------------ //
+
+Iterator TextEditor::begin() { return Iterator(this); }
+alni TextEditor::end() { return nullptr; }
+
+Iterator::Iterator(const TextEditor* aSelf) {
+	mSelf = aSelf;
+	mNode = mSelf->mPieces.first();
+	mVal = mSelf->getPieceLine(mNode->mPiece, 0)[0];
+}
+
+bool Iterator::inputLeft() {
+	return mNode;
+}
+
+Char Iterator::character() {
+	return mVal;
+}
+
+void Iterator::operator++() {
+	auto nl = isNewLineChar(mVal);
+	auto diff = Pointer{ nl, !nl };
+	mPtr += diff;
+	mOffset += diff;
+
+	if (mOffset == mNode->mPiece->diffPtr()) {
+		mNode = mNode->mNext;
+		mOffset = { 0, 0 };
+		if (!mNode) {
+			return;
+		}
+	}
+
+	mVal = mSelf->getPieceLine(mNode->mPiece, mOffset.mLine)[mOffset.mCol];
+}
+
+bool Iterator::operator!=(alni const& iter) {
+	return inputLeft();
+}
+
+bool Iterator::operator==(alni const& iter) {
+	return !inputLeft();
+}
+
+Char Iterator::operator->() { return mVal; }
+const Iterator& Iterator::operator*() { return *this; }

Strings/public/Logging.hpp

@@ -0,0 +1,59 @@
+
+#pragma once
+
+#include "Buffer.hpp"
+#include "List.hpp"
+#include "Strings.hpp"
+
+namespace tp {
+
+	class Logger {
+	public:
+
+		class Report {
+			String mData;
+			Buffer<ualni> mLineOffsets;
+
+		public:
+			enum Type { INFO, ERR, WARN, SUC } mType = INFO;
+
+		public:
+			Report();
+			explicit Report(const String& text);
+			Report(const String& text, Type type);
+
+		public:
+			[[nodiscard]] ualni getLineCount() const;
+			[[nodiscard]] String getString() const;
+
+		private:
+			void calcLineCount();
+		};
+
+	private:
+		List<Report>::Node* mCursor = nullptr;
+		List<Report> mBuff;
+		ualni mLineCount = 0;
+
+	public:
+		void write(const String& in, bool post = true, Report::Type type = Report::Type::INFO);
+
+		[[nodiscard]] String read();
+		[[nodiscard]] const List<Report>& getBuff() const { return mBuff; }
+		[[nodiscard]] ualni getLineCount() const { return mLineCount; }
+
+	public:
+		static void initializeGlobal();
+		static void deinitializeGlobal();
+	};
+
+	extern Logger* gLogger;
+}
+
+#define LOG(val) tp::str::gLogger->write((val), 1)
+
+#ifdef ENV_BUILD_DEBUG
+#define DEBUG_LOG(val) tp::str::gLogger->write((val), 1)
+#else
+#define DEBUG_LOG(val) (0)
+#endif

Strings/public/StringLogic.hpp

@@ -0,0 +1,174 @@
+#pragma once
+
+#include "Utils.hpp"
+
+namespace tp {
+
+	template<typename tChar = uint1>
+	class StringLogic {
+	public:
+
+		typedef halni Index;
+		typedef Index LineId;
+		typedef Index ColumnId;
+
+		static inline bool isNewLineChar(tChar in) { return (in == '\n') || (in == '\r'); }
+		static inline bool isEndChar(tChar in) { return in == '\0'; }
+		static constexpr tChar getEndChar() { return '\0'; }
+
+		static ualni calcLength(const tChar* in) {
+			const tChar* iter = in;
+			while (*iter != '\0') iter++;
+			return iter - in;
+		}
+
+		static tChar* insertLogic(const tChar* cur, const tChar* tar, ualni at, ualni len) {
+			ualni curLen = calcLength(cur);
+			ualni allLen = curLen + len;
+			auto* out = new tChar[allLen + 1];
+
+			DEBUG_ASSERT(curLen >= 0)
+			DEBUG_ASSERT(len >= 0)
+			DEBUG_ASSERT(at < curLen + 1 && at >= 0)
+
+			for (ualni idx = 0; idx < at; idx++) {
+				out[idx] = cur[idx];
+			}
+			for (ualni idx = 0; idx < len; idx++) {
+				out[idx + at] = tar[idx];
+			}
+			for (ualni idx = at + len; idx < allLen; idx++) {
+				out[idx] = cur[idx - len];
+			}
+			out[allLen] = '\0';
+			return out;
+		}
+
+		static tChar* removeLogic(const tChar* cur, ualni start, ualni end) {
+			ualni curLen = calcLength(cur);
+			ualni rangeLen = end - start;
+			ualni newLen = curLen - rangeLen;
+			auto* out = new tChar[newLen + 1];
+			out[newLen] = '\0';
+			for (ualni idx = 0; idx < start; idx++) {
+				out[idx] = cur[idx];
+			}
+			for (ualni idx = end; idx < curLen; idx++) {
+				out[idx - rangeLen] = cur[idx];
+			}
+			return out;
+		}
+
+		static bool isEqualLogic(const tChar* left, const tChar* right) {
+			ualni idx = 0;
+		LOOP:
+			if (left[idx] == '\0' || right[idx] == '\0') {
+				if (left[idx] == '\0' && right[idx] == '\0') {
+					return true;
+				}
+				return false;
+			}
+			if (left[idx] != right[idx]) {
+				return false;
+			}
+			idx++;
+			goto LOOP;
+		}
+
+		static ualni fromValueLength(alni val, ualni base) {
+			ualni iter = val;
+			ualni len = 0;
+			while (iter /= base) {
+				len++;
+			}
+			bool neg = val < 0;
+			len += 1 + ualni(neg);
+			return len;
+		}
+
+		static tChar* stringFromValue(alni val, tChar* ownBuff, ualni base) {
+			tChar* out;
+			bool neg = val < 0;
+			ualni len = fromValueLength(val, base);
+			out = ownBuff ? ownBuff : new tChar[len + 1];
+			out[len] = '\0';
+			val = abs(val);
+			for (ualni i = len - 1; i >= int(neg); i--) {
+				out[i] = (tChar) (val % base + 48);
+				val /= (alni) base;
+			}
+			if (neg) {
+				out[0] = '-';
+			}
+			return out;
+		}
+
+		static ualni fromValueLength(alnf val, ualni base) {
+			auto rounded = (alni) val;
+			ualni mantissa = ( (alni) val - rounded) * 100000;
+			alni rounded_len = 0;
+			alni mantissa_len = 0;
+			while (rounded /= (alni) base) {
+				rounded_len++;
+			}
+			if (!rounded_len) {
+				rounded_len++;
+			}
+			while (mantissa /= base) {
+				mantissa_len++;
+			}
+			bool neg = val < 0;
+			bool dot = mantissa_len & 1;
+			alni tot_len = mantissa_len + rounded_len + dot + neg;
+			return tot_len;
+		}
+
+		static tChar* fromValue(alnf, ualni, tChar*) {
+			DEBUG_BREAK(false)
+			return nullptr;
+		}
+
+		static ualni fromValueLength(bool val) {
+			return val ? 4 : 5;
+		}
+
+		static tChar* fromValue(bool val, tChar* ownBuff) {
+			alni len = val ? 4 : 5;
+			tChar* out = ownBuff ? ownBuff : new tChar[len + 1];
+			out[len] = '\0';
+			memCopy(out, val ? "True" : "False", len);
+			return out;
+		}
+
+		static tChar* stringFromValue(int val, ualni base) {
+			return fromValue((alni) val, nullptr, base);
+		}
+
+		static tChar* fromValue(tChar val) {
+			auto* out = new tChar[2];
+			out[1] = '\0';
+			out[0] = val;
+			return out;
+		}
+
+		static bool toValue(const tChar*, alni&, ualni) {
+			DEBUG_BREAK(false)
+			return false;
+		}
+
+		static bool toValue(const tChar*, alnf&, ualni) {
+			DEBUG_BREAK(false)
+			return false;
+		}
+
+		static bool toValue(const tChar* in, bool& val) {
+			if (!calcLength(in)) return false;
+			if (isEqual(in, "False") || isEqual(in, "false") || isEqual(in, "0")) {
+				val = false;
+			} else {
+				val = true;
+			}
+			return true;
+		}
+	};
+}

Strings/public/Strings.hpp

@@ -0,0 +1,248 @@
+#pragma once
+
+#include "PoolAllocator.hpp"
+#include "StringLogic.hpp"
+#include "TextEditor.hpp"
+
+namespace tp {
+
+	// Static data
+	extern ModuleManifest gModuleStrings;
+
+	template<typename tChar>
+	class StringTemplate;
+	using String = StringTemplate<uint1>;
+
+	template<typename tChar = uint1>
+	class StringTemplate {
+		typedef StringLogic<tChar> StringLogic;
+
+		// Hidden slave class
+		class StringData {
+
+			// allows to edit each string with text editor inplace
+			class TextEditors {
+				enum { MAX_EDITED_STRINGS = 65536 }; // 2^16 - do not change mindlessly
+				typedef uint2 Address;
+				ChunkAlloc<TextEditor*, MAX_EDITED_STRINGS> mEditorsPool;
+
+			public:
+				TextEditors() : mEditorsPool() {}
+
+				TextEditor* get(Address address) { return mEditorsPool.getBuff() + address;	}
+
+				Address createTextEditor(const tChar* originalBuffer) {
+					auto entry = (TextEditor**) mEditorsPool.allocate(0);
+					*entry = new TextEditor( originalBuffer );
+					return Address(entry - mEditorsPool.getBuff());
+				}
+
+				void destroyTextEditor(Address address) {
+					auto entry = mEditorsPool.getBuff() + address;
+					mEditorsPool.deallocate(entry);
+					delete entry;
+				}
+			};
+
+			static TextEditors sTextEditors;
+
+		public:
+			uint2 mIsConst; // source is non-modifiable
+			uint2 mEditedIdx; // editor id
+			uint4 mReferenceCount; // number of users of this
+			tChar* mBuff; // actual string data
+
+		public:
+			StringData() {
+				MODULE_SANITY_CHECK(gModuleStrings)
+				mBuff = (tChar*) "*";
+				mReferenceCount = 0;
+				mIsConst = true;
+				mEditedIdx = 0;
+			}
+
+			StringData(const tChar* aBuff, bool aIsConst) {
+				MODULE_SANITY_CHECK(gModuleStrings)
+				DEBUG_ASSERT(aBuff)
+				mBuff = (tChar*) aBuff;
+				mReferenceCount = 0;
+				mIsConst = aIsConst;
+				mEditedIdx = 0;
+			}
+
+			explicit StringData(const tChar* aBuff) {
+				MODULE_SANITY_CHECK(gModuleStrings)
+				DEBUG_ASSERT(aBuff)
+				auto const len = StringLogic::calcLength(aBuff);
+				resize(len);
+				memCopy(mBuff, aBuff, len);
+				mReferenceCount = 0;
+				mIsConst = false;
+				mEditedIdx = 0;
+			}
+
+			[[nodiscard]] tChar* getBuffer() {
+				DEBUG_ASSERT(!isEditorMode())
+				if (isEditorMode()) return nullptr;
+				return mBuff;
+			}
+
+			~StringData() {
+				if (!mIsConst) delete[] mBuff;
+				if (isEditorMode()) sTextEditors.destroyTextEditor(mEditedIdx);
+			}
+
+		public:
+			void resize(ualni size) {
+				DEBUG_ASSERT(!isEditorMode() && mReferenceCount == 1 && !mIsConst)
+				delete[] mBuff;
+				mBuff = new tChar[size + 1];
+				mBuff[size] = StringLogic::getEndChar();
+			}
+
+		public:
+			[[nodiscard]] bool isEditorMode() const { return mEditedIdx; }
+
+			void createEditor() {
+				DEBUG_ASSERT(!isEditorMode())
+				if (isEditorMode()) mEditedIdx = sTextEditors.createTextEditor(mBuff);
+			}
+
+			[[nodiscard]] TextEditor* getEditor() const {
+				DEBUG_ASSERT(isEditorMode())
+				if (!isEditorMode()) return nullptr;
+				return sTextEditors.get(mEditedIdx);
+			}
+
+			void applyEditor() {
+				DEBUG_ASSERT(isEditorMode() && mReferenceCount == 1 && !mIsConst)
+				if (!isEditorMode()) return;
+				auto editor = sTextEditors.get(mEditedIdx);
+				resize(editor.textSize());
+				for ( auto character : *editor) {
+					mBuff[character.idx] = character;
+				}
+			}
+
+			void destroyEditor() {
+				DEBUG_ASSERT(isEditorMode())
+				if (!isEditorMode()) return;
+				sTextEditors.destroyTextEditor(mEditedIdx);
+			}
+		};
+
+	private:
+		class StringData* mStringData;
+
+	private:
+		enum { STRINGS_POOL_SIZE = 1024, };
+		static PoolAlloc<StringData, STRINGS_POOL_SIZE>* sStringPool;
+		static StringData sNullString;
+
+		//  --------------------------------- Main Interface ---------------------------------//
+	public:
+		// Creates null string reference
+		StringTemplate() {
+			mStringData = &sNullString;
+			incReference(mStringData);
+		}
+
+		// References existing string data
+		StringTemplate(const StringTemplate& in) {
+			if (in.isEditorMode()) {
+				// Copies raw data and claims ownership over it
+				mStringData = new (sStringPool->allocate(0)) StringData(in.mStringData->mBuff);
+				incReference(mStringData);
+			} else {
+				mStringData = in.mStringData;
+				incReference(mStringData);
+			}
+		}
+
+		// Creates new string data from raw data pointer.
+		// Does not own string buffer - string buffer will not be freed. Initializes as const memory.
+		explicit StringTemplate(const tChar* raw) {
+			mStringData = new (sStringPool->allocate(0)) StringData(raw, true);
+			incReference(mStringData);
+		}
+
+		// Copies raw data and claims ownership over it
+		explicit StringTemplate(tChar* raw) {
+			mStringData = new (sStringPool->allocate(0)) StringData(raw);
+			incReference(mStringData);
+		}
+
+		~StringTemplate() {
+			decReference(mStringData);
+		}
+
+	private:
+
+		[[nodiscard]] bool isEditorMode() const {
+			return mStringData->isEditorMode();
+		}
+
+		static void incReference(StringData* dp) {
+			dp->mReferenceCount++;
+		}
+
+		void decReference(StringData* dp) {
+			dp->mReferenceCount--;
+			if (!dp->mReferenceCount) {
+				sStringPool->deallocate(mStringData);
+				mStringData->~StringData();
+			}
+		}
+
+	public: // Access
+		// used to read data
+		[[nodiscard]] const tChar* read() const {
+			return mStringData->mBuff;
+		}
+
+		// used to write data
+		// output will be null if in TextEditing mode
+		[[nodiscard]] tChar* write() {
+			makeModifiable();
+			return mStringData->getBuffer();
+		}
+
+		// output will be null if in TextEditing mode
+		[[nodiscard]] tChar* resize() {
+			if (!mStringData->getEditor()) mStringData->resize();
+			return mStringData->getBuffer();
+		}
+
+	public: // TextEditor Mode
+		// Enters TextEditor Mode
+		void createEditor() { mStringData->createEdited(); }
+
+		// Access to TextEditor Context & Interface
+		[[nodiscard]] TextEditor* getEditor() { return mStringData->getEdited(); }
+		[[nodiscard]] const TextEditor* getEditor() const { return mStringData->getEdited(); }
+
+		// Applies TextEditor Mode To Current buffer
+		void applyEditor() { mStringData->applyEditor(); }
+
+		// Leaves TextEditor Mode
+		void destroyEditor() { mStringData->destroyEditor(); }
+
+	private:
+		void makeModifiable() {
+			// We have no rights to modify if someone references that memory too
+			// So we need to create new copy of StringData
+			if (mStringData->mReferenceCount > 1) {
+				mStringData = new (sStringPool->allocate(0)) StringData(mStringData->mBuff);
+				incReference(mStringData);
+				return;
+			}
+
+			// Also if initial raw data was marked as const - create copy of raw data
+			// Note - raw data will be lost at this point if no other record of such is stored
+			if (mStringData->mIsConst) {
+				mStringData = new (sStringPool->allocate(0)) StringData(mStringData->mBuff);
+				incReference(mStringData);
+			}
+		}
+	};
+}

Strings/public/TextEditor.hpp

@@ -0,0 +1,382 @@
+
+#pragma once
+
+#include "Strings.hpp"
+#include "Buffer.hpp"
+#include "Tree.hpp"
+
+namespace tp {
+
+	class PiecesDS {
+
+		struct Input {
+			const Char* mInput = nullptr;
+			Index mLen = 0;
+			void getLineOffsets(Buffer<Index>& out);
+		};
+
+		struct Pointer {
+			LineId mLine;
+			ColumnId mCol;
+
+			Pointer();
+			Pointer(LineId aLine, ColumnId aCol);
+			Pointer(const Input& aInput);
+			void operator+=(Char achar);
+			void operator+=(const Pointer& ap);
+			Pointer operator-(const Pointer in) const;
+			Pointer operator+(const Pointer& ap) const;
+			bool operator==(const Pointer& in) const;
+			bool operator>(const Pointer& in) const;
+			bool operator>=(const Pointer& in) const;
+		};
+
+		struct Piece {
+			bool mAddedBuff = false;
+			Pointer mStart;
+			Pointer mEnd;
+
+			Pointer diffPtr() const;
+			LineId nLines() const;
+		};
+
+	public:
+
+		// Tree Node : Based on AvlNodeBlueprint
+		struct Node {
+
+			Node* mLeft = nullptr;
+			Node* mRight = nullptr;
+			Node* mParent = nullptr;
+			halni mHeight = 0;
+
+			Pointer mPtrLeft;
+			Pointer mPtrRight;
+			Pointer mDiff;
+
+			Node* mNext = nullptr;
+			Node* mPrev = nullptr;
+			Piece* mPiece = nullptr;
+
+			static bool mInsertionOperation;
+
+			Node() {}
+			Node(Pointer aKey) {
+				//mVal = aKey;
+			}
+
+			bool disentRight(Pointer aKey) const {
+				return aKey > mPtrLeft;
+			}
+
+			bool disentLeft(Pointer aKey) const {
+				return mPtrLeft > aKey;
+			}
+
+			bool exactNode(Pointer aKey) const {
+				if (mInsertionOperation) {
+					return aKey > mPtrLeft && mPtrLeft + mDiff > aKey;
+				}
+				return aKey >= mPtrLeft && mPtrLeft + mDiff > aKey;
+			}
+
+			Pointer getFindKey(Node* node = nullptr) const {
+				// node must be ancestor of this node
+
+				Pointer out = mPtrLeft;
+
+				if (node == this) {
+					return out;
+				}
+
+				auto iter = this;
+				while (iter->mParent != node) {
+					if (iter == iter->mParent->mRight) {
+						auto left_sub_tree = iter->mParent->mPtrLeft + iter->mParent->mDiff;
+						out = left_sub_tree + out;
+					}
+					iter = iter->mParent;
+				}
+
+				if (node) {
+					if (iter == iter->mParent->mRight) {
+						auto left_sub_tree = iter->mParent->mPtrLeft + iter->mParent->mDiff;
+						out = left_sub_tree + out;
+					}
+				}
+				return out;
+			}
+
+			void copyData(const Node& in) {
+				mPiece = in.mPiece;
+				mNext = in.mNext;
+				mPrev = in.mPrev;
+
+				if (mPrev) {
+					mPrev->mNext = this;
+				}
+
+				if (mNext) {
+					mNext->mPrev = this;
+				}
+			}
+
+			Pointer keyInRightSubtree(Pointer key) const { return key - (mPtrLeft + mDiff); }
+			Pointer keyInLeftSubtree(Pointer key) const { return key; }
+
+			void updateTreeCahceCallBack() {
+				DEBUG_ASSERT(mPiece);
+				mDiff = mPiece->diffPtr();
+				if (mLeft) {
+					mPtrLeft = mLeft->sum();
+				}
+				else {
+					mPtrLeft = { 0, 0 };
+				}
+
+				if (mRight) {
+					mPtrRight = mRight->sum();
+				}
+				else {
+					mPtrRight = { 0, 0 };
+				}
+			}
+
+			Pointer sum() const {
+				return (mPtrLeft + mDiff) + mPtrRight;
+			}
+		};
+
+	private:
+
+		AvlTree<Node, Pointer> mTree;
+
+	public:
+
+		PiecesDS() {
+		}
+
+		Node* find(Pointer ptr) const  {
+			return mTree.find(ptr);
+		}
+
+		Node* minNode(Node* node) const {
+			return mTree.minNode(node);
+		}
+
+		Node* maxNode(Node* node) const {
+			return mTree.maxNode(node);
+		}
+
+		Node* head() const {
+			return mTree.head();
+		}
+
+		void insert(const Node& node, Pointer ptr) {
+			Node::mInsertionOperation = true;
+			mTree.insert(ptr, node);
+			Node::mInsertionOperation = false;
+		}
+
+		Node* insertAfter(Node* node, Piece piece) {
+			auto key = node ? (node->getFindKey() + node->mDiff) : Pointer{ 0, 0 };
+			auto new_node = Node();
+			new_node.mPiece = new Piece(piece);
+
+			insert(new_node, key);
+
+#ifdef _DEBUG
+			auto err_node = mTree.isInvalid(mTree.head());
+			DBG_BREAK(err_node);
+#endif
+
+			auto out = mTree.find(key);
+
+			Node* next = out->mRight;
+			Node* prev = out->mLeft;
+
+			if (!(next || prev) && out->mParent) {
+				if (out->mParent->mLeft == out) {
+					next = out->mParent;
+				}
+				else {
+					prev = out->mParent;
+				}
+			}
+
+			if (next) {
+				out->mNext = next;
+				out->mPrev = next->mPrev;
+				next->mPrev = out;
+				if (out->mPrev) out->mPrev->mNext = out;
+			}
+			else if (prev) {
+				out->mPrev = prev;
+				out->mNext = prev->mNext;
+				prev->mNext = out;
+				if (out->mNext) out->mNext->mPrev = out;
+			}
+
+			return out;
+		}
+
+		void remove(Node* aNode) {
+			auto key = aNode->getFindKey();
+
+			if (aNode->mPrev) {
+				aNode->mPrev->mNext = aNode->mNext;
+			}
+
+			if (aNode->mNext) {
+				aNode->mNext->mPrev = aNode->mPrev;
+			}
+
+			auto del = aNode->mPiece;
+			mTree.remove(key);
+			delete del;
+
+#ifdef _DEBUG
+			auto err_node = mTree.isInvalid(mTree.head());
+			DBG_BREAK(err_node);
+#endif
+		}
+
+		Node* first() const {
+			return mTree.minNode(mTree.head());
+		}
+
+		Pointer ptrSum() const {
+			if (mTree.head()) {
+				return mTree.head()->sum();
+			}
+			return { 0, 0 };
+		}
+
+		halni nPieces() const {
+			return mTree.size();
+		}
+
+		void update_cache(Node* node) {
+			if (node) {
+				node->updateTreeCahceCallBack();
+				update_cache(node->mParent);
+			}
+		}
+
+		void undo() {}
+		void redo() {}
+		void pushUndoPoint() {}
+	};
+
+	struct AddBuff {
+		Buffer<Char> mBuff;
+		Buffer<Index> mLineOffsets;
+		Index mColumn = 0;
+
+		AddBuff();
+		void append(Input aInput);
+		Pointer endPtr();
+	};
+
+	struct OrigBuff {
+		bool mOwnsInput = false;
+		Input mOriginal;
+		Buffer<Index> mLineOffsets;
+
+		Pointer mPtrStart;
+		Pointer mPtrEnd;
+
+		// does not owns the original input by default
+		OrigBuff(Input aOriginal);
+
+		void makeOwnOriginalInput();
+
+		~OrigBuff();
+	};
+
+	struct PieceCrs {
+		Pointer piece_ptr;
+		Pointer offset;
+		Pointer ptr;
+		PiecesDS::Node* piece = nullptr;
+	};
+
+	class TextEditor {
+		friend class Iterator;
+
+		class Iterator {
+			friend TextEditor;
+
+			const TextEditor* mSelf;
+			PiecesDS::Node* mNode = nullptr;
+			Pointer mOffset = { 0, 0 };
+			Pointer mPtr = { 0, 0 };
+			Char mVal = 0;
+
+			Iterator(const TextEditor* mSelf);
+			bool inputLeft();
+
+		public:
+
+			Char character();
+			void operator++();
+			bool operator!=(alni const& iter);
+			bool operator==(alni const& iter);
+			Char operator->();
+			const Iterator& operator*();
+		};
+
+	public:
+
+		// pieces of strings that construct the text
+		PiecesDS mPieces;
+
+		// string buffers to wich pieces can reffer
+		OrigBuff mOrigBuff;
+		AddBuff mAddBuff;
+
+		// active position on the text
+		Pointer mCursor;
+		Pointer mCursorEnd;
+
+		Pointer mLastInsertionCrs;
+	//private:
+
+		[[nodiscard]] PieceCrs findPiece(Pointer ptr) const;
+		[[nodiscard]] Pointer prevPiecePtr(PiecesDS::Node* piece_node, Pointer piece_pointer) const;
+		[[nodiscard]] Pointer nextPiecePtr(PiecesDS::Node* piece_node, Pointer piece_pointer) const;
+
+		[[nodiscard]] const Char* getBuffLine(const Piece*, LineId) const;
+		[[nodiscard]] const Char* getPieceLine(const Piece*, LineId) const;
+		[[nodiscard]] PiecesDS::Node* splitPiece(PiecesDS::Node* piece, Pointer split_ptr);
+		[[nodiscard]] LineId getPieceLineLen(Piece* aPiece, LineId line) const;
+
+	public:
+		enum Dir : uint1 { LEFT, RIGHT, UP, DOWN };
+		enum DirUnit : uint1 { CHAR, WORD, TOK, LINE_END, LINE_START };
+
+	public:
+
+		TextEditor();
+		explicit TextEditor(Input original);
+
+		[[nodiscard]] Index mNLines() const;
+		void clampPtr(Pointer& ptr) const;
+		[[nodiscard]] Pointer getCursor() const;
+		[[nodiscard]] Pointer getCursorEnd() const;
+		void setCursor(Pointer ptr);
+		void setCursorEnd(Pointer ptr);
+
+		void insert(Input aInput);
+
+		void remove(bool only_selection = false, Dir dir = LEFT, DirUnit unit = CHAR);
+
+		void undo();
+		void redo();
+
+		Iterator begin();
+		alni end();
+
+		~TextEditor();
+	};
+}

Strings/tests/tests.cpp

@@ -0,0 +1,66 @@
+
+
+#include "common.h"
+
+#include "allocators.h"
+
+#include "strings.h"
+
+#include <iostream> 
+
+#include <stdio.h> 
+#include <string> 
+#include <algorithm> 
+
+#include "TextEditor.hpp"
+
+#include "Logging.hpp"
+
+using namespace tp;
+
+void test_conversions() {
+
+	for (auto i : tp::Range(1000)) {
+
+		auto sign = bool(std::rand() % 2) ? 1 : -1;
+
+		auto floating = std::rand() / (tp::alnf)std::rand() * sign;
+		auto tmp = std::to_string(floating);
+		auto left = tp::string(tmp.c_str());
+		auto right = tp::string(floating);
+		DBG_BREAK(left != right);
+		auto back = (tp::alnf)right;
+		//DBG_BREAK(back != floating);
+
+		auto integer = std::rand() * sign;
+		tmp = std::to_string(integer);
+		left = tp::string(tmp.c_str());
+		right = tp::string(integer);
+		DBG_BREAK(left != right);
+		back = (tp::alni)right;
+		DBG_BREAK(back != integer);
+	}
+}
+
+void test_editor() {
+	tp::string str = " initial ";
+	str.createEdited();
+	auto edited = str.getEdited();
+	edited->setCursor({0, 4});
+	edited->insert({"aaa", 3});
+	str.saveEdited();
+	str.clearEdited();
+
+	GLog->write(str, true);
+}
+
+int main() {
+	tp::alloc_init();
+	string::Initialize();
+	Logger::init();
+	//test_conversions();
+	test_editor();
+	Logger::deinit();
+	string::UnInitialize();
+	tp::alloc_uninit();
+}

TODO

@@ -7,7 +7,7 @@ Containers:
   Buffer 2d !
   Add check copy times
   AVL dont copy data just swap
-  More tests on buff and avl
+  More tests on mBuff and avl
 
 Strings:
   Implement