PieceTable: newline test from the line index, memchr rebuild; remove dead code

GetLine and LineColToByteOffset fetched each line's last byte (a piece
lookup, an allocation and a cache write) to see whether it was a newline;
the line index already says so: every line but the last ends at one.
LineColToByteOffset runs on every insert. RebuildLineIndex scans with
memchr instead of byte by byte.

Removed, having no callers: OptimizedSearch (built only into its own
test), UndoNodePool.h, SwapManager::RecordSplit/RecordJoin (replay still
reads SPLIT/JOIN), PieceTable::Reserve/Capacity and its capacity
constructor, Buffer's write-only render column, Editor's mode, no-kill,
dirtyex and repeatable flags and the UCount getter, and
RetryPolicy::Conservative.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_015rcVQiiWyTzoNrsvLSaAfB

Buffer.cc

@@ -347,7 +347,6 @@ Buffer::Buffer(const Buffer &other)
 {
 	curx_             = other.curx_;
 	cury_             = other.cury_;
-	rx_               = other.rx_;
 	nrows_            = other.nrows_;
 	rowoffs_          = other.rowoffs_;
 	coloffs_          = other.coloffs_;
@@ -401,7 +400,6 @@ Buffer::operator=(const Buffer &other)
 		return *this;
 	curx_             = other.curx_;
 	cury_             = other.cury_;
-	rx_               = other.rx_;
 	nrows_            = other.nrows_;
 	rowoffs_          = other.rowoffs_;
 	coloffs_          = other.coloffs_;
@@ -450,7 +448,6 @@ Buffer::operator=(const Buffer &other)
 Buffer::Buffer(Buffer &&other) noexcept
 	: curx_(other.curx_),
 	  cury_(other.cury_),
-	  rx_(other.rx_),
 	  nrows_(other.nrows_),
 	  rowoffs_(other.rowoffs_),
 	  coloffs_(other.coloffs_),
@@ -502,7 +499,6 @@ Buffer::operator=(Buffer &&other) noexcept
 
 	curx_                 = other.curx_;
 	cury_                 = other.cury_;
-	rx_                   = other.rx_;
 	nrows_                = other.nrows_;
 	rowoffs_              = other.rowoffs_;
 	coloffs_              = other.coloffs_;
@@ -593,7 +589,7 @@ Buffer::OpenFromFile(const std::string &path, std::string &err)
 		dirty_          = false;
 
 		// Reset cursor/viewport state
-		curx_      = cury_    = rx_ = 0;
+		curx_      = cury_    = 0;
 		rowoffs_   = coloffs_ = 0;
 		mark_set_  = false;
 		mark_curx_ = mark_cury_ = 0;
@@ -687,7 +683,7 @@ Buffer::OpenFromFile(const std::string &path, std::string &err)
 	MarkContentChanged();
 
 	// Reset cursor/viewport state
-	curx_      = cury_    = rx_ = 0;
+	curx_      = cury_    = 0;
 	rowoffs_   = coloffs_ = 0;
 	mark_set_  = false;
 	mark_curx_ = mark_cury_ = 0;

Buffer.h

@@ -5,7 +5,7 @@
  * or scratch document and manages:
  *
  * - Content storage: Uses PieceTable for efficient text operations
- * - Cursor state: Current position (curx_, cury_), rendered column (rx_)
+ * - Cursor state: Current position (curx_, cury_)
  * - Viewport: Scroll offsets (rowoffs_, coloffs_) for display
  * - File backing: Optional association with a file on disk
  * - Undo/Redo: Integrated UndoSystem for operation history
@@ -17,7 +17,6 @@
  *
  * 1. Cursor coordinates:
  *    - (curx_, cury_): Logical character position in the document
- *    - rx_: Rendered column accounting for tab expansion
  *
  * 2. File backing:
  *    - Buffers can be file-backed (associated with a path) or scratch (unnamed)
@@ -119,12 +118,6 @@ public:
 	}
 
 
-	[[nodiscard]] std::size_t Rx() const
-	{
-		return rx_;
-	}
-
-
 	[[nodiscard]] std::size_t Nrows() const
 	{
 		return content_LineCount_();
@@ -394,12 +387,6 @@ public:
 	}
 
 
-	void SetRenderX(const std::size_t rx)
-	{
-		rx_ = rx;
-	}
-
-
 	void SetOffsets(const std::size_t row, const std::size_t col)
 	{
 		rowoffs_ = row;
@@ -740,7 +727,6 @@ private:
 
 	// State mirroring original C struct (without undo_tree)
 	std::size_t curx_    = 0, cury_ = 0; // cursor position in characters
-	std::size_t rx_      = 0; // render x (tabs expanded)
 	std::size_t nrows_   = 0; // number of rows
 	std::size_t rowoffs_ = 0, coloffs_ = 0; // viewport offsets
 	mutable std::vector<Line> rows_; // materialized cache of rows (without trailing newlines)

CMakeLists.txt

@@ -389,7 +389,6 @@ if (BUILD_TESTS)
             tests/test_swap_cleanup2.cc
             tests/test_swap_git_editor.cc
             tests/test_piece_table.cc
-            tests/test_search.cc
             tests/test_search_replace_flow.cc
             tests/test_reflow_paragraph.cc
             tests/test_reflow_indented_bullets.cc
@@ -418,7 +417,6 @@ if (BUILD_TESTS)
             SearchHighlight.cc
             KKeymap.cc
             SwapRecorder.h
-            OptimizedSearch.cc
             UndoNode.cc
             UndoTree.cc
             UndoSystem.cc

Command.cc

@@ -265,7 +265,6 @@ ensure_cursor_visible(const Editor &ed, Buffer &buf)
 	}
 
 	buf.SetOffsets(rowoffs, coloffs);
-	buf.SetRenderX(rx);
 }
 
 
@@ -3051,7 +3050,6 @@ cmd_show_help(CommandContext &ctx)
 		b.SetDirty(false);
 		b.SetCursor(0, 0);
 		b.SetOffsets(0, 0);
-		b.SetRenderX(0);
 	};
 
 	if (help_index != static_cast<std::size_t>(-1)) {

Editor.cc

@@ -728,15 +728,11 @@ void
 Editor::Reset()
 {
 	rows_    = cols_ = 0;
-	mode_    = 0;
 	kill_    = 0;
-	no_kill_ = 0;
-	dirtyex_ = 0;
 	msg_.clear();
 	msgtm_                = 0;
 	uarg_                 = 0;
 	ucount_               = 0;
-	repeatable_           = false;
 	quit_requested_       = false;
 	quit_confirm_pending_ = false;
 	// Reset close-confirm/save state

Editor.h

@@ -79,19 +79,6 @@ public:
 	}
 
 
-	// Mode and flags (mirroring legacy fields)
-	void SetMode(int m)
-	{
-		mode_ = m;
-	}
-
-
-	[[nodiscard]] int Mode() const
-	{
-		return mode_;
-	}
-
-
 	void SetKillChain(bool on)
 	{
 		kill_ = on ? 1 : 0;
@@ -104,18 +91,6 @@ public:
 	}
 
 
-	void SetNoKill(bool on)
-	{
-		no_kill_ = on ? 1 : 0;
-	}
-
-
-	[[nodiscard]] bool NoKill() const
-	{
-		return no_kill_ != 0;
-	}
-
-
 	// Kill ring API
 	void KillRingClear()
 	{
@@ -164,18 +139,6 @@ public:
 	}
 
 
-	void SetDirtyEx(int d)
-	{
-		dirtyex_ = d;
-	}
-
-
-	[[nodiscard]] int DirtyEx() const
-	{
-		return dirtyex_;
-	}
-
-
 	void SetUniversalArg(int uarg, int ucount)
 	{
 		uarg_   = uarg;
@@ -189,12 +152,6 @@ public:
 	}
 
 
-	[[nodiscard]] int UCount() const
-	{
-		return ucount_;
-	}
-
-
 	// --- Universal argument control (C-u) ---
 	// Begin or extend a universal argument (like ke's uarg_start)
 	void UArgStart();
@@ -209,19 +166,6 @@ public:
 	// If no universal argument active, returns 1.
 	int UArgGet();
 
-	// Repeatable command flag: input layer can mark the next command as repeatable
-	void SetRepeatable(bool on)
-	{
-		repeatable_ = on;
-	}
-
-
-	[[nodiscard]] bool Repeatable() const
-	{
-		return repeatable_;
-	}
-
-
 	// Status message storage. Rendering is renderer-dependent; the editor
 	// merely stores the current message and its timestamp.
 	void SetStatus(const std::string &message);
@@ -666,14 +610,10 @@ private:
 	};
 
 	std::size_t rows_ = 0, cols_ = 0;
-	int mode_         = 0;
 	int kill_         = 0; // KILL CHAIN
-	int no_kill_      = 0; // don't kill in delete_row
-	int dirtyex_      = 0;
 	std::string msg_;
 	std::time_t msgtm_ = 0;
 	int uarg_          = 0, ucount_ = 0; // C-u support
-	bool repeatable_   = false; // whether the next command is repeatable
 
 	std::vector<Buffer> buffers_;
 	std::vector<Buffer> *shared_buffers_ = nullptr; // if set, use this instead of buffers_

ErrorRecovery.h

@@ -52,11 +52,6 @@ struct RetryPolicy {
 	}
 
 
-	// Conservative policy for non-critical operations: fewer attempts, slower retries
-	static RetryPolicy Conservative()
-	{
-		return RetryPolicy{2, std::chrono::milliseconds(200), 2.5, std::chrono::milliseconds(10000)};
-	}
 };
 
 // Retry a function with exponential backoff for transient errors

OptimizedSearch.cc

@@ -1,79 +0,0 @@
-#include "OptimizedSearch.h"
-
-#include <algorithm>
-
-
-void
-OptimizedSearch::build_bad_char(const std::string &pattern)
-{
-	if (pattern == last_pat_)
-		return;
-	last_pat_ = pattern;
-	std::fill(bad_char_.begin(), bad_char_.end(), -1);
-	for (std::size_t i = 0; i < pattern.size(); ++i) {
-		bad_char_[static_cast<unsigned char>(pattern[i])] = static_cast<int>(i);
-	}
-}
-
-
-std::size_t
-OptimizedSearch::find_first(const std::string &text, const std::string &pattern, std::size_t start)
-{
-	const std::size_t n = text.size();
-	const std::size_t m = pattern.size();
-	if (m == 0)
-		return start <= n ? start : std::string::npos;
-	if (m > n || start >= n)
-		return std::string::npos;
-	build_bad_char(pattern);
-	std::size_t s = start;
-	while (s <= n - m) {
-		std::size_t j = m;
-		while (j > 0 && pattern[j - 1] == text[s + j - 1]) {
-			--j;
-		}
-		if (j == 0) {
-			return s; // match found
-		}
-		unsigned char badc = static_cast<unsigned char>(text[s + j - 1]);
-		int bcidx          = bad_char_[badc];
-		std::size_t shift  = (j - 1 > static_cast<std::size_t>(bcidx))
-			                    ? (j - 1 - static_cast<std::size_t>(bcidx))
-			                    : 1;
-		s += shift;
-	}
-	return std::string::npos;
-}
-
-
-std::vector<std::size_t>
-OptimizedSearch::find_all(const std::string &text, const std::string &pattern, std::size_t start)
-{
-	std::vector<std::size_t> res;
-	const std::size_t n = text.size();
-	const std::size_t m = pattern.size();
-	if (m == 0)
-		return res;
-	if (m > n || start >= n)
-		return res;
-	build_bad_char(pattern);
-	std::size_t s = start;
-	while (s <= n - m) {
-		std::size_t j = m;
-		while (j > 0 && pattern[j - 1] == text[s + j - 1]) {
-			--j;
-		}
-		if (j == 0) {
-			res.push_back(s);
-			s += m; // non-overlapping
-			continue;
-		}
-		unsigned char badc = static_cast<unsigned char>(text[s + j - 1]);
-		int bcidx          = bad_char_[badc];
-		std::size_t shift  = (j - 1 > static_cast<std::size_t>(bcidx))
-			                    ? (j - 1 - static_cast<std::size_t>(bcidx))
-			                    : 1;
-		s += shift;
-	}
-	return res;
-}

OptimizedSearch.h

@@ -1,23 +0,0 @@
-// OptimizedSearch.h - Boyer–Moore (bad character) based substring search
-#pragma once
-#include <array>
-#include <cstddef>
-#include <string>
-#include <vector>
-
-class OptimizedSearch {
-public:
-	OptimizedSearch() = default;
-
-	// Find first occurrence at or after start. Returns npos if not found.
-	std::size_t find_first(const std::string &text, const std::string &pattern, std::size_t start = 0);
-
-	// Find all non-overlapping matches at or after start. Returns starting indices.
-	std::vector<std::size_t> find_all(const std::string &text, const std::string &pattern, std::size_t start = 0);
-
-private:
-	std::array<int, 256> bad_char_{};
-	std::string last_pat_;
-
-	void build_bad_char(const std::string &pattern);
-};

PieceTable.cc

@@ -10,13 +10,6 @@
 PieceTable::PieceTable() = default;
 
 
-PieceTable::PieceTable(const std::size_t initialCapacity)
-{
-	add_.reserve(initialCapacity);
-	materialized_.reserve(initialCapacity);
-}
-
-
 PieceTable::PieceTable(const std::size_t initialCapacity,
                        const std::size_t piece_limit,
                        const std::size_t small_piece_threshold,
@@ -109,14 +102,6 @@ PieceTable::operator=(PieceTable &&other) noexcept
 PieceTable::~PieceTable() = default;
 
 
-void
-PieceTable::Reserve(const std::size_t newCapacity)
-{
-	add_.reserve(newCapacity);
-	materialized_.reserve(newCapacity);
-}
-
-
 // Setter to allow tuning consolidation heuristics
 void
 PieceTable::SetConsolidationParams(const std::size_t piece_limit,
@@ -417,12 +402,10 @@ PieceTable::RebuildLineIndex() const
 		const std::string &src = pc.src == Source::Original ? original_ : add_;
 		const char *base       = src.data() + static_cast<std::ptrdiff_t>(pc.start);
 
-		for (std::size_t j = 0; j < pc.len; ++j) {
+		const char *end        = base + pc.len;
-			if (base[j] == '\n') {
+		// The next line starts after each newline.
-				// next line starts after the newline
+		for (const char *p = base; (p = static_cast<const char *>(std::memchr(p, '\n', end - p))) != nullptr; ++p)
-				line_index_.push_back(pos + j + 1);
+			line_index_.push_back(pos + static_cast<std::size_t>(p - base) + 1);
-			}
-		}
 
 		pos += pc.len;
 	}
@@ -800,14 +783,10 @@ PieceTable::GetLine(std::size_t line_num) const
 	auto [start, end] = GetLineRange(line_num);
 	if (end < start)
 		return std::string();
-	// Trim trailing '\n'
+	// Every line but the last ends at a newline (each newline starts an
-	if (end > start) {
+	// index entry); leave it out.
-		// To check last char, we can get it via GetRange of len 1 at end-1 without materializing whole
+	if (end > start && line_num + 1 < line_index_.size())
-		std::string last = GetRange(end - 1, 1);
-		if (!last.empty() && last[0] == '\n') {
 		end -= 1;
-		}
-	}
 	return GetRange(start, end - start);
 }
 
@@ -837,13 +816,10 @@ PieceTable::LineColToByteOffset(std::size_t row, std::size_t col) const
 		return total_size_;
 	std::size_t start = line_index_[row];
 	std::size_t end   = (row + 1 < line_index_.size()) ? line_index_[row + 1] : total_size_;
-	// Clamp col to line length excluding trailing newline
+	// Clamp col to the line's length without its newline (every line but
-	if (end > start) {
+	// the last has one).
-		std::string last = GetRange(end - 1, 1);
+	if (end > start && row + 1 < line_index_.size())
-		if (!last.empty() && last[0] == '\n') {
 		end -= 1;
-		}
-	}
 	std::size_t target = start + std::min(col, end - start);
 	return target;
 }

PieceTable.h

@@ -52,8 +52,6 @@ class PieceTable {
 public:
 	PieceTable();
 
-	explicit PieceTable(std::size_t initialCapacity);
-
 	// Advanced constructor allowing configuration of consolidation heuristics
 	PieceTable(std::size_t initialCapacity,
 	           std::size_t piece_limit,
@@ -70,9 +68,6 @@ public:
 
 	~PieceTable();
 
-	// Public API mirrors GapBuffer
-	void Reserve(std::size_t newCapacity);
-
 	void AppendChar(char c);
 
 	void Append(const char *s, std::size_t len);
@@ -109,13 +104,6 @@ public:
 	}
 
 
-	[[nodiscard]] std::size_t Capacity() const
-	{
-		// Capacity for piece table isn't directly meaningful; report materialized capacity
-		return materialized_.capacity();
-	}
-
-
 	// ===== New buffer-wide API (Phase 1) =====
 	// Byte-based editing operations
 	void Insert(std::size_t byte_offset, const char *text, std::size_t len);

Swap.cc

@@ -1202,47 +1202,6 @@ SwapManager::RecordDelete(Buffer &buf, int row, int col, std::size_t len)
 }
 
 
-void
-SwapManager::RecordSplit(Buffer &buf, int row, int col)
-{
-	{
-		std::lock_guard<std::mutex> lg(mtx_);
-		auto it = journals_.find(&buf);
-		if (it == journals_.end() || it->second.suspended)
-			return;
-	}
-	Pending p;
-	p.buf  = &buf;
-	p.type = SwapRecType::SPLIT;
-	// payload v1: [encver u8=1][row u32][col u32]
-	p.payload.push_back(1);
-	put_le32(p.payload, static_cast<std::uint32_t>(std::max(0, row)));
-	put_le32(p.payload, static_cast<std::uint32_t>(std::max(0, col)));
-	enqueue(std::move(p));
-	maybe_request_checkpoint(buf, 1);
-}
-
-
-void
-SwapManager::RecordJoin(Buffer &buf, int row)
-{
-	{
-		std::lock_guard<std::mutex> lg(mtx_);
-		auto it = journals_.find(&buf);
-		if (it == journals_.end() || it->second.suspended)
-			return;
-	}
-	Pending p;
-	p.buf  = &buf;
-	p.type = SwapRecType::JOIN;
-	// payload v1: [encver u8=1][row u32]
-	p.payload.push_back(1);
-	put_le32(p.payload, static_cast<std::uint32_t>(std::max(0, row)));
-	enqueue(std::move(p));
-	maybe_request_checkpoint(buf, 1);
-}
-
-
 void
 SwapManager::maybe_request_checkpoint(Buffer &buf, const std::size_t approx_edit_bytes)
 {

Swap.h

@@ -24,6 +24,7 @@ namespace kte {
 enum class SwapRecType : std::uint8_t {
 	INS = 1,
 	DEL = 2,
+	// SPLIT and JOIN are no longer written; replay still reads them.
 	SPLIT = 3,
 	JOIN = 4,
 	META = 0xF0,
@@ -213,10 +214,6 @@ private:
 
 	void RecordDelete(Buffer &buf, int row, int col, std::size_t len);
 
-	void RecordSplit(Buffer &buf, int row, int col);
-
-	void RecordJoin(Buffer &buf, int row);
-
 	void RecordCheckpoint(Buffer &buf, bool urgent_flush);
 
 	void maybe_request_checkpoint(Buffer &buf, std::size_t approx_edit_bytes);

UndoNodePool.h

@@ -1,63 +0,0 @@
-#pragma once
-#include <stack>
-#include <vector>
-#include <memory>
-#include "UndoNode.h"
-
-// Pool allocator for UndoNode to eliminate frequent malloc/free.
-// Uses fixed-size blocks to keep node addresses stable.
-class UndoNodePool {
-public:
-	explicit UndoNodePool(std::size_t block_size = 64)
-		: block_size_(block_size) {}
-
-
-	UndoNode *acquire()
-	{
-		if (available_.empty())
-			allocate_block();
-		auto *node = available_.top();
-		available_.pop();
-		// Node comes zeroed; ensure links are reset
-		node->text.clear();
-		node->parent = nullptr;
-		node->child  = nullptr;
-		node->next   = nullptr;
-		node->row    = node->col = 0;
-		node->type   = UndoType{};
-		return node;
-	}
-
-
-	void release(UndoNode *node)
-	{
-		if (!node)
-			return;
-		// Clear heavy fields to free memory held by strings
-		node->text.clear();
-		node->parent = nullptr;
-		node->child  = nullptr;
-		node->next   = nullptr;
-		node->row    = node->col = 0;
-		node->type   = UndoType{};
-		available_.push(node);
-	}
-
-private:
-	void allocate_block()
-	{
-		// allocate a new block; keep ownership so memory stays valid
-		std::unique_ptr<UndoNode[]> block(new UndoNode[block_size_]);
-		UndoNode *base = block.get();
-		blocks_.push_back(std::move(block));
-		for (std::size_t i = 0; i < block_size_; ++i) {
-			// ensure the node is reset; rely on default constructor/zero init
-			available_.push(&base[i]);
-		}
-	}
-
-
-	std::size_t block_size_;
-	std::vector<std::unique_ptr<UndoNode[]> > blocks_;
-	std::stack<UndoNode *> available_;
-};

tests/test_search.cc

@@ -1,46 +0,0 @@
-#include "Test.h"
-#include "OptimizedSearch.h"
-#include <string>
-#include <vector>
-
-
-static std::vector<std::size_t>
-ref_find_all(const std::string &text, const std::string &pat)
-{
-	std::vector<std::size_t> res;
-	if (pat.empty())
-		return res;
-	std::size_t from = 0;
-	while (true) {
-		auto p = text.find(pat, from);
-		if (p == std::string::npos)
-			break;
-		res.push_back(p);
-		from = p + pat.size();
-	}
-	return res;
-}
-
-
-TEST(OptimizedSearch_basic_cases)
-{
-	OptimizedSearch os;
-	struct Case {
-		std::string text;
-		std::string pat;
-	} cases[] = {
-		{"", ""},
-		{"", "a"},
-		{"a", ""},
-		{"a", "a"},
-		{"aaaaa", "aa"},
-		{"hello world", "world"},
-		{"abcabcabc", "abc"},
-		{"the quick brown fox", "fox"},
-	};
-	for (auto &c: cases) {
-		auto got = os.find_all(c.text, c.pat, 0);
-		auto ref = ref_find_all(c.text, c.pat);
-		ASSERT_EQ(got, ref);
-	}
-}