From e089c6e4d1059232fa2a710c0d5659079b6ca1f8 Mon Sep 17 00:00:00 2001
From: Kyle Isom <kyle@imap.cc>
Date: Mon, 1 Dec 2025 20:09:49 -0800
Subject: [PATCH] LSP integration steps 1-4, part of 5.

---
 .idea/codeStyles/Project.xml     |   7 +
 Buffer.cc                        |  48 ++++
 Buffer.h                         |  73 +++++-
 CMakeLists.txt                   | 391 +++++++++++++++--------------
 Command.cc                       | 249 ++++++++++---------
 Command.h                        |  10 +-
 CppHighlighter.cc                | 413 +++++++++++++++++++------------
 CppHighlighter.h                 |  29 +--
 Editor.cc                        | 187 +++++++-------
 GUIConfig.cc                     |  46 ++--
 GUIConfig.h                      |  24 +-
 GUIFrontend.cc                   |  74 +++---
 GUIRenderer.cc                   | 140 ++++++-----
 GUITheme.h                       | 115 +++++----
 GoHighlighter.cc                 | 179 +++++++++++---
 GoHighlighter.h                  |  16 +-
 Highlight.h                      |  44 ++--
 HighlighterEngine.cc             | 302 ++++++++++++----------
 HighlighterEngine.h              |  97 ++++----
 HighlighterRegistry.cc           | 268 ++++++++++++--------
 HighlighterRegistry.h            |  48 ++--
 JsonHighlighter.cc               | 116 ++++++---
 JsonHighlighter.h                |   6 +-
 LanguageHighlighter.h            |  48 ++--
 LispHighlighter.cc               | 122 ++++++---
 LispHighlighter.h                |  14 +-
 MarkdownHighlighter.cc           | 198 +++++++++------
 MarkdownHighlighter.h            |  10 +-
 NullHighlighter.cc               |  21 +-
 NullHighlighter.h                |   6 +-
 PythonHighlighter.cc             | 221 ++++++++++++-----
 PythonHighlighter.h              |  18 +-
 RustHighlighter.cc               | 158 ++++++++++--
 RustHighlighter.h                |  16 +-
 ShellHighlighter.cc              | 132 +++++++---
 ShellHighlighter.h               |   6 +-
 TerminalRenderer.cc              | 270 ++++++++++----------
 TreeSitterHighlighter.cc         |  43 ++--
 TreeSitterHighlighter.h          |  30 +--
 lsp/BufferChangeTracker.cc       |  49 ++++
 lsp/BufferChangeTracker.h        |  44 ++++
 lsp/Diagnostic.h                 |  37 +++
 lsp/DiagnosticDisplay.h          |  30 +++
 lsp/DiagnosticStore.cc           | 123 +++++++++
 lsp/DiagnosticStore.h            |  42 ++++
 lsp/JsonRpcTransport.cc          |  19 ++
 lsp/JsonRpcTransport.h           |  29 +++
 lsp/LspClient.h                  |  61 +++++
 lsp/LspManager.cc                | 326 ++++++++++++++++++++++++
 lsp/LspManager.h                 |  85 +++++++
 lsp/LspProcessClient.cc          |  72 ++++++
 lsp/LspProcessClient.h           |  47 ++++
 lsp/LspServerConfig.h            |  47 ++++
 lsp/LspTypes.h                   |  29 +++
 lsp/TerminalDiagnosticDisplay.cc |  53 ++++
 lsp/TerminalDiagnosticDisplay.h  |  35 +++
 56 files changed, 3685 insertions(+), 1638 deletions(-)
 create mode 100644 lsp/BufferChangeTracker.cc
 create mode 100644 lsp/BufferChangeTracker.h
 create mode 100644 lsp/Diagnostic.h
 create mode 100644 lsp/DiagnosticDisplay.h
 create mode 100644 lsp/DiagnosticStore.cc
 create mode 100644 lsp/DiagnosticStore.h
 create mode 100644 lsp/JsonRpcTransport.cc
 create mode 100644 lsp/JsonRpcTransport.h
 create mode 100644 lsp/LspClient.h
 create mode 100644 lsp/LspManager.cc
 create mode 100644 lsp/LspManager.h
 create mode 100644 lsp/LspProcessClient.cc
 create mode 100644 lsp/LspProcessClient.h
 create mode 100644 lsp/LspServerConfig.h
 create mode 100644 lsp/LspTypes.h
 create mode 100644 lsp/TerminalDiagnosticDisplay.cc
 create mode 100644 lsp/TerminalDiagnosticDisplay.h

diff --git a/.idea/codeStyles/Project.xml b/.idea/codeStyles/Project.xml
index f1b3720..876f8ed 100644
--- a/.idea/codeStyles/Project.xml
+++ b/.idea/codeStyles/Project.xml
@@ -141,6 +141,13 @@
         <pair source="c++m" header="" fileNamingConvention="NONE" />
       </extensions>
     </files>
+    <codeStyleSettings language="CMake">
+      <indentOptions>
+        <option name="INDENT_SIZE" value="8" />
+        <option name="TAB_SIZE" value="8" />
+        <option name="USE_TAB_CHARACTER" value="true" />
+      </indentOptions>
+    </codeStyleSettings>
     <codeStyleSettings language="ObjectiveC">
       <indentOptions>
         <option name="INDENT_SIZE" value="8" />
diff --git a/Buffer.cc b/Buffer.cc
index bceb1da..7a2b419 100644
--- a/Buffer.cc
+++ b/Buffer.cc
@@ -9,6 +9,7 @@
 // For reconstructing highlighter state on copies
 #include "HighlighterRegistry.h"
 #include "NullHighlighter.h"
+#include "lsp/BufferChangeTracker.h"
 
 
 Buffer::Buffer()
@@ -19,6 +20,9 @@ Buffer::Buffer()
 }
 
 
+Buffer::~Buffer() = default;
+
+
 Buffer::Buffer(const std::string &path)
 {
 	std::string err;
@@ -394,6 +398,30 @@ Buffer::AsString() const
 }
 
 
+std::string
+Buffer::FullText() const
+{
+	std::string out;
+	// Precompute size for fewer reallocations
+	std::size_t total = 0;
+	for (std::size_t i = 0; i < rows_.size(); ++i) {
+		total += rows_[i].Size();
+		if (i + 1 < rows_.size())
+			total += 1; // for '\n'
+	}
+	out.reserve(total);
+	for (std::size_t i = 0; i < rows_.size(); ++i) {
+		const char *d = rows_[i].Data();
+		std::size_t n = rows_[i].Size();
+		if (d && n)
+			out.append(d, n);
+		if (i + 1 < rows_.size())
+			out.push_back('\n');
+	}
+	return out;
+}
+
+
 // --- Raw editing APIs (no undo recording, cursor untouched) ---
 void
 Buffer::insert_text(int row, int col, std::string_view text)
@@ -432,6 +460,9 @@ Buffer::insert_text(int row, int col, std::string_view text)
 		remain.erase(0, pos + 1);
 	}
 	// Do not set dirty here; UndoSystem will manage state/dirty externally
+	if (change_tracker_) {
+		change_tracker_->recordInsertion(row, col, std::string(text));
+	}
 }
 
 
@@ -470,6 +501,9 @@ Buffer::delete_text(int row, int col, std::size_t len)
 			break;
 		}
 	}
+	if (change_tracker_) {
+		change_tracker_->recordDeletion(row, col, len);
+	}
 }
 
 
@@ -543,3 +577,17 @@ Buffer::Undo() const
 {
 	return undo_sys_.get();
 }
+
+
+void
+Buffer::SetChangeTracker(std::unique_ptr<kte::lsp::BufferChangeTracker> tracker)
+{
+	change_tracker_ = std::move(tracker);
+}
+
+
+kte::lsp::BufferChangeTracker *
+Buffer::GetChangeTracker()
+{
+	return change_tracker_.get();
+}
\ No newline at end of file
diff --git a/Buffer.h b/Buffer.h
index 926f67c..3cfb3b0 100644
--- a/Buffer.h
+++ b/Buffer.h
@@ -17,11 +17,20 @@
 #include "HighlighterEngine.h"
 #include "Highlight.h"
 
+// Forward declarations to avoid heavy includes
+namespace kte {
+namespace lsp {
+class BufferChangeTracker;
+}
+}
+
 
 class Buffer {
 public:
 	Buffer();
 
+	~Buffer();
+
 	Buffer(const Buffer &other);
 
 	Buffer &operator=(const Buffer &other);
@@ -374,23 +383,59 @@ public:
 
 	[[nodiscard]] std::string AsString() const;
 
+	// Compose full text of this buffer with newlines between rows
+	[[nodiscard]] std::string FullText() const;
+
 	// Syntax highlighting integration (per-buffer)
-	[[nodiscard]] std::uint64_t Version() const { return version_; }
+	[[nodiscard]] std::uint64_t Version() const
+	{
+		return version_;
+	}
 
-	void SetSyntaxEnabled(bool on) { syntax_enabled_ = on; }
-	[[nodiscard]] bool SyntaxEnabled() const { return syntax_enabled_; }
 
-	void SetFiletype(const std::string &ft) { filetype_ = ft; }
-	[[nodiscard]] const std::string &Filetype() const { return filetype_; }
+	void SetSyntaxEnabled(bool on)
+	{
+		syntax_enabled_ = on;
+	}
+
+
+	[[nodiscard]] bool SyntaxEnabled() const
+	{
+		return syntax_enabled_;
+	}
+
+
+	void SetFiletype(const std::string &ft)
+	{
+		filetype_ = ft;
+	}
+
+
+	[[nodiscard]] const std::string &Filetype() const
+	{
+		return filetype_;
+	}
+
+
+	kte::HighlighterEngine *Highlighter()
+	{
+		return highlighter_.get();
+	}
+
+
+	const kte::HighlighterEngine *Highlighter() const
+	{
+		return highlighter_.get();
+	}
 
-	kte::HighlighterEngine *Highlighter() { return highlighter_.get(); }
-	const kte::HighlighterEngine *Highlighter() const { return highlighter_.get(); }
 
 	void EnsureHighlighter()
 	{
-		if (!highlighter_) highlighter_ = std::make_unique<kte::HighlighterEngine>();
+		if (!highlighter_)
+			highlighter_ = std::make_unique<kte::HighlighterEngine>();
 	}
 
+
 	// Raw, low-level editing APIs used by UndoSystem apply().
 	// These must NOT trigger undo recording. They also do not move the cursor.
 	void insert_text(int row, int col, std::string_view text);
@@ -410,6 +455,11 @@ public:
 
 	[[nodiscard]] const UndoSystem *Undo() const;
 
+	// LSP integration: optional change tracker
+	void SetChangeTracker(std::unique_ptr<kte::lsp::BufferChangeTracker> tracker);
+
+	kte::lsp::BufferChangeTracker *GetChangeTracker();
+
 private:
 	// State mirroring original C struct (without undo_tree)
 	std::size_t curx_    = 0, cury_ = 0; // cursor position in characters
@@ -430,9 +480,12 @@ private:
 
 	// Syntax/highlighting state
 	std::uint64_t version_ = 0; // increment on edits
- bool syntax_enabled_    = true;
+	bool syntax_enabled_   = true;
 	std::string filetype_;
 	std::unique_ptr<kte::HighlighterEngine> highlighter_;
+
+	// Optional LSP change tracker (absent by default)
+	std::unique_ptr<kte::lsp::BufferChangeTracker> change_tracker_;
 };
 
-#endif // KTE_BUFFER_H
+#endif // KTE_BUFFER_H
\ No newline at end of file
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 32d0bf2..e09ea3c 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -16,36 +16,36 @@ option(KTE_UNDO_DEBUG "Enable undo instrumentation logs" OFF)
 option(KTE_ENABLE_TREESITTER "Enable optional Tree-sitter highlighter adapter" OFF)
 
 if (CMAKE_HOST_UNIX)
-    message(STATUS "Build system is POSIX.")
+	message(STATUS "Build system is POSIX.")
 else ()
-    message(STATUS "Build system is NOT POSIX.")
+	message(STATUS "Build system is NOT POSIX.")
 endif ()
 
 if (MSVC)
-    add_compile_options("/W4" "$<$<CONFIG:RELEASE>:/O2>")
+	add_compile_options("/W4" "$<$<CONFIG:RELEASE>:/O2>")
 else ()
-    add_compile_options(
-            "-Wall"
-            "-Wextra"
-            "-Werror"
-            "$<$<CONFIG:DEBUG>:-g>"
-            "$<$<CONFIG:RELEASE>:-O2>")
-    if ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "Clang")
-        add_compile_options("-stdlib=libc++")
-    else ()
-        # nothing special for gcc at the moment
-    endif ()
+	add_compile_options(
+		"-Wall"
+		"-Wextra"
+		"-Werror"
+		"$<$<CONFIG:DEBUG>:-g>"
+		"$<$<CONFIG:RELEASE>:-O2>")
+	if ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "Clang")
+		add_compile_options("-stdlib=libc++")
+	else ()
+		# nothing special for gcc at the moment
+	endif ()
 endif ()
 add_compile_definitions(KGE_PLATFORM=${CMAKE_HOST_SYSTEM_NAME})
 add_compile_definitions(KTE_VERSION_STR="v${KTE_VERSION}")
 if (KTE_ENABLE_TREESITTER)
-    add_compile_definitions(KTE_ENABLE_TREESITTER)
+	add_compile_definitions(KTE_ENABLE_TREESITTER)
 endif ()
 
 message(STATUS "Build system: ${CMAKE_HOST_SYSTEM_NAME}")
 
 if (${BUILD_GUI})
-    include(cmake/imgui.cmake)
+	include(cmake/imgui.cmake)
 endif ()
 
 # NCurses for terminal mode
@@ -55,222 +55,239 @@ find_package(Curses REQUIRED)
 include_directories(${CURSES_INCLUDE_DIR})
 
 set(COMMON_SOURCES
-        GapBuffer.cc
-        PieceTable.cc
-        Buffer.cc
-        Editor.cc
-        Command.cc
-        HelpText.cc
-        KKeymap.cc
-        TerminalInputHandler.cc
-        TerminalRenderer.cc
-        TerminalFrontend.cc
-        TestInputHandler.cc
-        TestRenderer.cc
-        TestFrontend.cc
-        UndoNode.cc
-        UndoTree.cc
-        UndoSystem.cc
-        HighlighterEngine.cc
-        CppHighlighter.cc
-        HighlighterRegistry.cc
-        NullHighlighter.cc
-        JsonHighlighter.cc
-        MarkdownHighlighter.cc
-        ShellHighlighter.cc
-        GoHighlighter.cc
-        PythonHighlighter.cc
-        RustHighlighter.cc
-        LispHighlighter.cc
+	GapBuffer.cc
+	PieceTable.cc
+	Buffer.cc
+	Editor.cc
+	Command.cc
+	HelpText.cc
+	KKeymap.cc
+	TerminalInputHandler.cc
+	TerminalRenderer.cc
+	TerminalFrontend.cc
+	TestInputHandler.cc
+	TestRenderer.cc
+	TestFrontend.cc
+	UndoNode.cc
+	UndoTree.cc
+	UndoSystem.cc
+	HighlighterEngine.cc
+	CppHighlighter.cc
+	HighlighterRegistry.cc
+	NullHighlighter.cc
+	JsonHighlighter.cc
+	MarkdownHighlighter.cc
+	ShellHighlighter.cc
+	GoHighlighter.cc
+	PythonHighlighter.cc
+	RustHighlighter.cc
+	LispHighlighter.cc
+	lsp/BufferChangeTracker.cc
+	lsp/JsonRpcTransport.cc
+	lsp/LspProcessClient.cc
+	lsp/DiagnosticStore.cc
+	lsp/TerminalDiagnosticDisplay.cc
+	lsp/LspManager.cc
 )
 
 if (KTE_ENABLE_TREESITTER)
-    list(APPEND COMMON_SOURCES
-            TreeSitterHighlighter.cc)
+	list(APPEND COMMON_SOURCES
+		TreeSitterHighlighter.cc)
 endif ()
 
 set(COMMON_HEADERS
-        GapBuffer.h
-        PieceTable.h
-        Buffer.h
-        Editor.h
-        AppendBuffer.h
-        Command.h
-        HelpText.h
-        KKeymap.h
-        InputHandler.h
-        TerminalInputHandler.h
-        Renderer.h
-        TerminalRenderer.h
-        Frontend.h
-        TerminalFrontend.h
-        TestInputHandler.h
-        TestRenderer.h
-        TestFrontend.h
-        UndoNode.h
-        UndoTree.h
-        UndoSystem.h
-        Highlight.h
-        LanguageHighlighter.h
-        HighlighterEngine.h
-        CppHighlighter.h
-        HighlighterRegistry.h
-        NullHighlighter.h
-        JsonHighlighter.h
-        MarkdownHighlighter.h
-        ShellHighlighter.h
-        GoHighlighter.h
-        PythonHighlighter.h
-        RustHighlighter.h
-        LispHighlighter.h
+	GapBuffer.h
+	PieceTable.h
+	Buffer.h
+	Editor.h
+	AppendBuffer.h
+	Command.h
+	HelpText.h
+	KKeymap.h
+	InputHandler.h
+	TerminalInputHandler.h
+	Renderer.h
+	TerminalRenderer.h
+	Frontend.h
+	TerminalFrontend.h
+	TestInputHandler.h
+	TestRenderer.h
+	TestFrontend.h
+	UndoNode.h
+	UndoTree.h
+	UndoSystem.h
+	Highlight.h
+	LanguageHighlighter.h
+	HighlighterEngine.h
+	CppHighlighter.h
+	HighlighterRegistry.h
+	NullHighlighter.h
+	JsonHighlighter.h
+	MarkdownHighlighter.h
+	ShellHighlighter.h
+	GoHighlighter.h
+	PythonHighlighter.h
+	RustHighlighter.h
+	LispHighlighter.h
+	lsp/LspTypes.h
+	lsp/BufferChangeTracker.h
+	lsp/JsonRpcTransport.h
+	lsp/LspClient.h
+	lsp/LspProcessClient.h
+	lsp/Diagnostic.h
+	lsp/DiagnosticStore.h
+	lsp/DiagnosticDisplay.h
+	lsp/TerminalDiagnosticDisplay.h
+	lsp/LspManager.h
+	lsp/LspServerConfig.h
 )
 
 if (KTE_ENABLE_TREESITTER)
-    list(APPEND COMMON_HEADERS
-            TreeSitterHighlighter.h)
+	list(APPEND COMMON_HEADERS
+		TreeSitterHighlighter.h)
 endif ()
 
 # kte (terminal-first) executable
 add_executable(kte
-        main.cc
-        ${COMMON_SOURCES}
-        ${COMMON_HEADERS}
+	main.cc
+	${COMMON_SOURCES}
+	${COMMON_HEADERS}
 )
 
 if (KTE_USE_PIECE_TABLE)
-    target_compile_definitions(kte PRIVATE KTE_USE_PIECE_TABLE=1)
+	target_compile_definitions(kte PRIVATE KTE_USE_PIECE_TABLE=1)
 endif ()
 if (KTE_UNDO_DEBUG)
-    target_compile_definitions(kte PRIVATE KTE_UNDO_DEBUG=1)
+	target_compile_definitions(kte PRIVATE KTE_UNDO_DEBUG=1)
 endif ()
 
 target_link_libraries(kte ${CURSES_LIBRARIES})
 
 if (KTE_ENABLE_TREESITTER)
-    # Users can provide their own tree-sitter include/lib via cache variables
-    set(TREESITTER_INCLUDE_DIR "" CACHE PATH "Path to tree-sitter include directory")
-    set(TREESITTER_LIBRARY "" CACHE FILEPATH "Path to tree-sitter library (.a/.dylib)")
-    if (TREESITTER_INCLUDE_DIR)
-        target_include_directories(kte PRIVATE ${TREESITTER_INCLUDE_DIR})
-    endif ()
-    if (TREESITTER_LIBRARY)
-        target_link_libraries(kte ${TREESITTER_LIBRARY})
-    endif ()
+	# Users can provide their own tree-sitter include/lib via cache variables
+	set(TREESITTER_INCLUDE_DIR "" CACHE PATH "Path to tree-sitter include directory")
+	set(TREESITTER_LIBRARY "" CACHE FILEPATH "Path to tree-sitter library (.a/.dylib)")
+	if (TREESITTER_INCLUDE_DIR)
+		target_include_directories(kte PRIVATE ${TREESITTER_INCLUDE_DIR})
+	endif ()
+	if (TREESITTER_LIBRARY)
+		target_link_libraries(kte ${TREESITTER_LIBRARY})
+	endif ()
 endif ()
 
 install(TARGETS kte
-        RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
+	RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
 )
 
 # Man pages
 install(FILES docs/kte.1 DESTINATION ${CMAKE_INSTALL_MANDIR}/man1)
 
 if (BUILD_TESTS)
-    # test_undo executable for testing undo/redo system
-    add_executable(test_undo
-            test_undo.cc
-            ${COMMON_SOURCES}
-            ${COMMON_HEADERS}
-    )
+	# test_undo executable for testing undo/redo system
+	add_executable(test_undo
+		test_undo.cc
+		${COMMON_SOURCES}
+		${COMMON_HEADERS}
+	)
 
-    if (KTE_USE_PIECE_TABLE)
-        target_compile_definitions(test_undo PRIVATE KTE_USE_PIECE_TABLE=1)
-    endif ()
+	if (KTE_USE_PIECE_TABLE)
+		target_compile_definitions(test_undo PRIVATE KTE_USE_PIECE_TABLE=1)
+	endif ()
 
-    if (KTE_UNDO_DEBUG)
-        target_compile_definitions(test_undo PRIVATE KTE_UNDO_DEBUG=1)
-    endif ()
+	if (KTE_UNDO_DEBUG)
+		target_compile_definitions(test_undo PRIVATE KTE_UNDO_DEBUG=1)
+	endif ()
 
 
-    target_link_libraries(test_undo ${CURSES_LIBRARIES})
-    if (KTE_ENABLE_TREESITTER)
-        if (TREESITTER_INCLUDE_DIR)
-            target_include_directories(test_undo PRIVATE ${TREESITTER_INCLUDE_DIR})
-        endif ()
-        if (TREESITTER_LIBRARY)
-            target_link_libraries(test_undo ${TREESITTER_LIBRARY})
-        endif ()
-    endif ()
+	target_link_libraries(test_undo ${CURSES_LIBRARIES})
+	if (KTE_ENABLE_TREESITTER)
+		if (TREESITTER_INCLUDE_DIR)
+			target_include_directories(test_undo PRIVATE ${TREESITTER_INCLUDE_DIR})
+		endif ()
+		if (TREESITTER_LIBRARY)
+			target_link_libraries(test_undo ${TREESITTER_LIBRARY})
+		endif ()
+	endif ()
 endif ()
 
 if (${BUILD_GUI})
-    target_sources(kte PRIVATE
-            Font.h
-            GUIConfig.cc
-            GUIConfig.h
-            GUIRenderer.cc
-            GUIRenderer.h
-            GUIInputHandler.cc
-            GUIInputHandler.h
-            GUIFrontend.cc
-            GUIFrontend.h)
-    target_compile_definitions(kte PRIVATE KTE_BUILD_GUI=1)
-    target_link_libraries(kte imgui)
+	target_sources(kte PRIVATE
+		Font.h
+		GUIConfig.cc
+		GUIConfig.h
+		GUIRenderer.cc
+		GUIRenderer.h
+		GUIInputHandler.cc
+		GUIInputHandler.h
+		GUIFrontend.cc
+		GUIFrontend.h)
+	target_compile_definitions(kte PRIVATE KTE_BUILD_GUI=1)
+	target_link_libraries(kte imgui)
 
-    # kge (GUI-first) executable
-    add_executable(kge
-            main.cc
-            ${COMMON_SOURCES}
-            ${COMMON_HEADERS}
-            GUIConfig.cc
-            GUIConfig.h
-            GUIRenderer.cc
-            GUIRenderer.h
-            GUIInputHandler.cc
-            GUIInputHandler.h
-            GUIFrontend.cc
-            GUIFrontend.h)
-    target_compile_definitions(kge PRIVATE KTE_BUILD_GUI=1 KTE_DEFAULT_GUI=1 KTE_FONT_SIZE=${KTE_FONT_SIZE})
-    if (KTE_UNDO_DEBUG)
-        target_compile_definitions(kge PRIVATE KTE_UNDO_DEBUG=1)
-    endif ()
-    target_link_libraries(kge ${CURSES_LIBRARIES} imgui)
+	# kge (GUI-first) executable
+	add_executable(kge
+		main.cc
+		${COMMON_SOURCES}
+		${COMMON_HEADERS}
+		GUIConfig.cc
+		GUIConfig.h
+		GUIRenderer.cc
+		GUIRenderer.h
+		GUIInputHandler.cc
+		GUIInputHandler.h
+		GUIFrontend.cc
+		GUIFrontend.h)
+	target_compile_definitions(kge PRIVATE KTE_BUILD_GUI=1 KTE_DEFAULT_GUI=1 KTE_FONT_SIZE=${KTE_FONT_SIZE})
+	if (KTE_UNDO_DEBUG)
+		target_compile_definitions(kge PRIVATE KTE_UNDO_DEBUG=1)
+	endif ()
+	target_link_libraries(kge ${CURSES_LIBRARIES} imgui)
 
-    # On macOS, build kge as a proper .app bundle
-    if (APPLE)
-        # Define the icon file
-        set(MACOSX_BUNDLE_ICON_FILE kge.icns)
-        set(kge_ICON "${CMAKE_CURRENT_SOURCE_DIR}/${MACOSX_BUNDLE_ICON_FILE}")
+	# On macOS, build kge as a proper .app bundle
+	if (APPLE)
+		# Define the icon file
+		set(MACOSX_BUNDLE_ICON_FILE kge.icns)
+		set(kge_ICON "${CMAKE_CURRENT_SOURCE_DIR}/${MACOSX_BUNDLE_ICON_FILE}")
 
-        # Add icon to the target sources and mark it as a resource
-        target_sources(kge PRIVATE ${kge_ICON})
-        set_source_files_properties(${kge_ICON} PROPERTIES
-                MACOSX_PACKAGE_LOCATION Resources)
+		# Add icon to the target sources and mark it as a resource
+		target_sources(kge PRIVATE ${kge_ICON})
+		set_source_files_properties(${kge_ICON} PROPERTIES
+			MACOSX_PACKAGE_LOCATION Resources)
 
-        # Configure Info.plist with version and identifiers
-        set(KGE_BUNDLE_ID "dev.wntrmute.kge")
-        configure_file(
-                ${CMAKE_CURRENT_LIST_DIR}/cmake/Info.plist.in
-                ${CMAKE_CURRENT_BINARY_DIR}/kge-Info.plist
-                @ONLY)
+		# Configure Info.plist with version and identifiers
+		set(KGE_BUNDLE_ID "dev.wntrmute.kge")
+		configure_file(
+			${CMAKE_CURRENT_LIST_DIR}/cmake/Info.plist.in
+			${CMAKE_CURRENT_BINARY_DIR}/kge-Info.plist
+			@ONLY)
 
-        set_target_properties(kge PROPERTIES
-                MACOSX_BUNDLE TRUE
-                MACOSX_BUNDLE_GUI_IDENTIFIER ${KGE_BUNDLE_ID}
-                MACOSX_BUNDLE_BUNDLE_NAME "kge"
-                MACOSX_BUNDLE_ICON_FILE ${MACOSX_BUNDLE_ICON_FILE}
-                MACOSX_BUNDLE_INFO_PLIST "${CMAKE_CURRENT_BINARY_DIR}/kge-Info.plist")
+		set_target_properties(kge PROPERTIES
+			MACOSX_BUNDLE TRUE
+			MACOSX_BUNDLE_GUI_IDENTIFIER ${KGE_BUNDLE_ID}
+			MACOSX_BUNDLE_BUNDLE_NAME "kge"
+			MACOSX_BUNDLE_ICON_FILE ${MACOSX_BUNDLE_ICON_FILE}
+			MACOSX_BUNDLE_INFO_PLIST "${CMAKE_CURRENT_BINARY_DIR}/kge-Info.plist")
 
-        add_dependencies(kge kte)
-        add_custom_command(TARGET kge POST_BUILD
-                COMMAND ${CMAKE_COMMAND} -E copy
-                $<TARGET_FILE:kte>
-                $<TARGET_FILE_DIR:kge>/kte
-                COMMENT "Copying kte binary into kge.app bundle")
+		add_dependencies(kge kte)
+		add_custom_command(TARGET kge POST_BUILD
+			COMMAND ${CMAKE_COMMAND} -E copy
+			$<TARGET_FILE:kte>
+			$<TARGET_FILE_DIR:kge>/kte
+			COMMENT "Copying kte binary into kge.app bundle")
 
-        install(TARGETS kge
-                BUNDLE DESTINATION .
-        )
+		install(TARGETS kge
+			BUNDLE DESTINATION .
+		)
 
-        install(TARGETS kte
-                RUNTIME DESTINATION kge.app/Contents/MacOS
-        )
-    else ()
-        install(TARGETS kge
-                RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
-        )
-    endif ()
-    # Install kge man page only when GUI is built
-    install(FILES docs/kge.1 DESTINATION ${CMAKE_INSTALL_MANDIR}/man1)
-    install(FILES kge.png DESTINATION ${CMAKE_INSTALL_PREFIX}/share/icons)
+		install(TARGETS kte
+			RUNTIME DESTINATION kge.app/Contents/MacOS
+		)
+	else ()
+		install(TARGETS kge
+			RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
+		)
+	endif ()
+	# Install kge man page only when GUI is built
+	install(FILES docs/kge.1 DESTINATION ${CMAKE_INSTALL_MANDIR}/man1)
+	install(FILES kge.png DESTINATION ${CMAKE_INSTALL_PREFIX}/share/icons)
 endif ()
diff --git a/Command.cc b/Command.cc
index 3b5a12f..144605c 100644
--- a/Command.cc
+++ b/Command.cc
@@ -762,122 +762,140 @@ cmd_unknown_kcommand(CommandContext &ctx)
 	return true;
 }
 
+
 // --- Syntax highlighting commands ---
-static void apply_filetype(Buffer &buf, const std::string &ft)
+static void
+apply_filetype(Buffer &buf, const std::string &ft)
 {
-    buf.EnsureHighlighter();
-    auto *eng = buf.Highlighter();
-    if (!eng) return;
-    std::string val = ft;
-    // trim + lower
-    auto trim = [](const std::string &s){
-        std::string r = s;
-        auto notsp = [](int ch){ return !std::isspace(ch); };
-        r.erase(r.begin(), std::find_if(r.begin(), r.end(), notsp));
-        r.erase(std::find_if(r.rbegin(), r.rend(), notsp).base(), r.end());
-        return r;
-    };
-    val = trim(val);
-    for (auto &ch: val) ch = static_cast<char>(std::tolower(static_cast<unsigned char>(ch)));
-    if (val == "off") {
-        eng->SetHighlighter(nullptr);
-        buf.SetFiletype("");
-        buf.SetSyntaxEnabled(false);
-        return;
-    }
-    if (val.empty()) {
-        // Empty means unknown/unspecified -> use NullHighlighter but keep syntax enabled
-        buf.SetFiletype("");
-        buf.SetSyntaxEnabled(true);
-        eng->SetHighlighter(std::make_unique<kte::NullHighlighter>());
-        eng->InvalidateFrom(0);
-        return;
-    }
-    // Normalize and create via registry
-    std::string norm = kte::HighlighterRegistry::Normalize(val);
-    auto hl = kte::HighlighterRegistry::CreateFor(norm);
-    if (hl) {
-        eng->SetHighlighter(std::move(hl));
-        buf.SetFiletype(norm);
-        buf.SetSyntaxEnabled(true);
-        eng->InvalidateFrom(0);
-    } else {
-        // Unknown -> install NullHighlighter and keep syntax enabled
-        eng->SetHighlighter(std::make_unique<kte::NullHighlighter>());
-        buf.SetFiletype(val); // record what user asked even if unsupported
-        buf.SetSyntaxEnabled(true);
-        eng->InvalidateFrom(0);
-    }
+	buf.EnsureHighlighter();
+	auto *eng = buf.Highlighter();
+	if (!eng)
+		return;
+	std::string val = ft;
+	// trim + lower
+	auto trim = [](const std::string &s) {
+		std::string r = s;
+		auto notsp    = [](int ch) {
+			return !std::isspace(ch);
+		};
+		r.erase(r.begin(), std::find_if(r.begin(), r.end(), notsp));
+		r.erase(std::find_if(r.rbegin(), r.rend(), notsp).base(), r.end());
+		return r;
+	};
+	val = trim(val);
+	for (auto &ch: val)
+		ch = static_cast<char>(std::tolower(static_cast<unsigned char>(ch)));
+	if (val == "off") {
+		eng->SetHighlighter(nullptr);
+		buf.SetFiletype("");
+		buf.SetSyntaxEnabled(false);
+		return;
+	}
+	if (val.empty()) {
+		// Empty means unknown/unspecified -> use NullHighlighter but keep syntax enabled
+		buf.SetFiletype("");
+		buf.SetSyntaxEnabled(true);
+		eng->SetHighlighter(std::make_unique<kte::NullHighlighter>());
+		eng->InvalidateFrom(0);
+		return;
+	}
+	// Normalize and create via registry
+	std::string norm = kte::HighlighterRegistry::Normalize(val);
+	auto hl          = kte::HighlighterRegistry::CreateFor(norm);
+	if (hl) {
+		eng->SetHighlighter(std::move(hl));
+		buf.SetFiletype(norm);
+		buf.SetSyntaxEnabled(true);
+		eng->InvalidateFrom(0);
+	} else {
+		// Unknown -> install NullHighlighter and keep syntax enabled
+		eng->SetHighlighter(std::make_unique<kte::NullHighlighter>());
+		buf.SetFiletype(val); // record what user asked even if unsupported
+		buf.SetSyntaxEnabled(true);
+		eng->InvalidateFrom(0);
+	}
 }
 
-static bool cmd_syntax(CommandContext &ctx)
+
+static bool
+cmd_syntax(CommandContext &ctx)
 {
-    Buffer *b = ctx.editor.CurrentBuffer();
-    if (!b) {
-        ctx.editor.SetStatus("No buffer");
-        return true;
-    }
-    std::string arg = ctx.arg;
-    // trim
-    auto trim = [](std::string &s){
-        auto notsp = [](int ch){ return !std::isspace(ch); };
-        s.erase(s.begin(), std::find_if(s.begin(), s.end(), notsp));
-        s.erase(std::find_if(s.rbegin(), s.rend(), notsp).base(), s.end());
-    };
-    trim(arg);
-    if (arg == "on") {
-        b->SetSyntaxEnabled(true);
-        // If no highlighter but filetype is cpp by extension, set it
-        if (!b->Highlighter() || !b->Highlighter()->HasHighlighter()) {
-            apply_filetype(*b, b->Filetype().empty() ? std::string("cpp") : b->Filetype());
-        }
-        ctx.editor.SetStatus("syntax: on");
-    } else if (arg == "off") {
-        b->SetSyntaxEnabled(false);
-        ctx.editor.SetStatus("syntax: off");
-    } else if (arg == "reload") {
-        if (auto *eng = b->Highlighter()) eng->InvalidateFrom(0);
-        ctx.editor.SetStatus("syntax: reloaded");
-    } else {
-        ctx.editor.SetStatus("usage: :syntax on|off|reload");
-    }
-    return true;
+	Buffer *b = ctx.editor.CurrentBuffer();
+	if (!b) {
+		ctx.editor.SetStatus("No buffer");
+		return true;
+	}
+	std::string arg = ctx.arg;
+	// trim
+	auto trim = [](std::string &s) {
+		auto notsp = [](int ch) {
+			return !std::isspace(ch);
+		};
+		s.erase(s.begin(), std::find_if(s.begin(), s.end(), notsp));
+		s.erase(std::find_if(s.rbegin(), s.rend(), notsp).base(), s.end());
+	};
+	trim(arg);
+	if (arg == "on") {
+		b->SetSyntaxEnabled(true);
+		// If no highlighter but filetype is cpp by extension, set it
+		if (!b->Highlighter() || !b->Highlighter()->HasHighlighter()) {
+			apply_filetype(*b, b->Filetype().empty() ? std::string("cpp") : b->Filetype());
+		}
+		ctx.editor.SetStatus("syntax: on");
+	} else if (arg == "off") {
+		b->SetSyntaxEnabled(false);
+		ctx.editor.SetStatus("syntax: off");
+	} else if (arg == "reload") {
+		if (auto *eng = b->Highlighter())
+			eng->InvalidateFrom(0);
+		ctx.editor.SetStatus("syntax: reloaded");
+	} else {
+		ctx.editor.SetStatus("usage: :syntax on|off|reload");
+	}
+	return true;
 }
 
-static bool cmd_set_option(CommandContext &ctx)
+
+static bool
+cmd_set_option(CommandContext &ctx)
 {
-    Buffer *b = ctx.editor.CurrentBuffer();
-    if (!b) {
-        ctx.editor.SetStatus("No buffer");
-        return true;
-    }
-    // Expect key=value
-    auto eq = ctx.arg.find('=');
-    if (eq == std::string::npos) {
-        ctx.editor.SetStatus("usage: :set key=value");
-        return true;
-    }
-    std::string key = ctx.arg.substr(0, eq);
-    std::string val = ctx.arg.substr(eq + 1);
-    // trim
-    auto trim = [](std::string &s){
-        auto notsp = [](int ch){ return !std::isspace(ch); };
-        s.erase(s.begin(), std::find_if(s.begin(), s.end(), notsp));
-        s.erase(std::find_if(s.rbegin(), s.rend(), notsp).base(), s.end());
-    };
-    trim(key); trim(val);
-    // lower-case value for filetype
-    for (auto &ch: val) ch = static_cast<char>(std::tolower(static_cast<unsigned char>(ch)));
-    if (key == "filetype") {
-        apply_filetype(*b, val);
-        if (b->SyntaxEnabled())
-            ctx.editor.SetStatus(std::string("filetype: ") + (b->Filetype().empty()?"off":b->Filetype()));
-        else
-            ctx.editor.SetStatus("filetype: off");
-        return true;
-    }
-    ctx.editor.SetStatus("unknown option: " + key);
-    return true;
+	Buffer *b = ctx.editor.CurrentBuffer();
+	if (!b) {
+		ctx.editor.SetStatus("No buffer");
+		return true;
+	}
+	// Expect key=value
+	auto eq = ctx.arg.find('=');
+	if (eq == std::string::npos) {
+		ctx.editor.SetStatus("usage: :set key=value");
+		return true;
+	}
+	std::string key = ctx.arg.substr(0, eq);
+	std::string val = ctx.arg.substr(eq + 1);
+	// trim
+	auto trim = [](std::string &s) {
+		auto notsp = [](int ch) {
+			return !std::isspace(ch);
+		};
+		s.erase(s.begin(), std::find_if(s.begin(), s.end(), notsp));
+		s.erase(std::find_if(s.rbegin(), s.rend(), notsp).base(), s.end());
+	};
+	trim(key);
+	trim(val);
+	// lower-case value for filetype
+	for (auto &ch: val)
+		ch = static_cast<char>(std::tolower(static_cast<unsigned char>(ch)));
+	if (key == "filetype") {
+		apply_filetype(*b, val);
+		if (b->SyntaxEnabled())
+			ctx.editor.SetStatus(
+				std::string("filetype: ") + (b->Filetype().empty() ? "off" : b->Filetype()));
+		else
+			ctx.editor.SetStatus("filetype: off");
+		return true;
+	}
+	ctx.editor.SetStatus("unknown option: " + key);
+	return true;
 }
 
 
@@ -907,6 +925,7 @@ cmd_theme_next(CommandContext &ctx)
 	return true;
 }
 
+
 static bool
 cmd_theme_prev(CommandContext &ctx)
 {
@@ -3734,12 +3753,12 @@ InstallDefaultCommands()
 		CommandId::ChangeWorkingDirectory, "change-working-directory", "Change current working directory",
 		cmd_change_working_directory_start
 	});
-    // UI helpers
-    CommandRegistry::Register(
-        {CommandId::UArgStatus, "uarg-status", "Update universal-arg status", cmd_uarg_status});
-    // Syntax highlighting (public commands)
-    CommandRegistry::Register({CommandId::Syntax, "syntax", "Syntax: on|off|reload", cmd_syntax, true});
-    CommandRegistry::Register({CommandId::SetOption, "set", "Set option: key=value", cmd_set_option, true});
+	// UI helpers
+	CommandRegistry::Register(
+		{CommandId::UArgStatus, "uarg-status", "Update universal-arg status", cmd_uarg_status});
+	// Syntax highlighting (public commands)
+	CommandRegistry::Register({CommandId::Syntax, "syntax", "Syntax: on|off|reload", cmd_syntax, true});
+	CommandRegistry::Register({CommandId::SetOption, "set", "Set option: key=value", cmd_set_option, true});
 }
 
 
@@ -3781,4 +3800,4 @@ Execute(Editor &ed, const std::string &name, const std::string &arg, int count)
 		return false;
 	CommandContext ctx{ed, arg, count};
 	return cmd->handler ? cmd->handler(ctx) : false;
-}
+}
\ No newline at end of file
diff --git a/Command.h b/Command.h
index 7ee15eb..20ede02 100644
--- a/Command.h
+++ b/Command.h
@@ -94,10 +94,10 @@ enum class CommandId {
 	// Theme by name
 	ThemeSetByName,
 	// Background mode (GUI)
-    BackgroundSet,
-    // Syntax highlighting
-    Syntax,        // ":syntax on|off|reload"
-    SetOption,     // generic ":set key=value" (v1: filetype=<lang>)
+	BackgroundSet,
+	// Syntax highlighting
+	Syntax, // ":syntax on|off|reload"
+	SetOption, // generic ":set key=value" (v1: filetype=<lang>)
 };
 
 
@@ -151,4 +151,4 @@ bool Execute(Editor &ed, CommandId id, const std::string &arg = std::string(), i
 
 bool Execute(Editor &ed, const std::string &name, const std::string &arg = std::string(), int count = 0);
 
-#endif // KTE_COMMAND_H
+#endif // KTE_COMMAND_H
\ No newline at end of file
diff --git a/CppHighlighter.cc b/CppHighlighter.cc
index c1e0f9c..2ba3a93 100644
--- a/CppHighlighter.cc
+++ b/CppHighlighter.cc
@@ -3,168 +3,277 @@
 #include <cctype>
 
 namespace kte {
+static bool
+is_digit(char c)
+{
+	return c >= '0' && c <= '9';
+}
 
-static bool is_digit(char c) { return c >= '0' && c <= '9'; }
 
 CppHighlighter::CppHighlighter()
 {
-    const char *kw[] = {
-        "if","else","for","while","do","switch","case","default","break","continue",
-        "return","goto","struct","class","namespace","using","template","typename",
-        "public","private","protected","virtual","override","const","constexpr","auto",
-        "static","inline","operator","new","delete","try","catch","throw","friend",
-        "enum","union","extern","volatile","mutable","noexcept","sizeof","this"
-    };
-    for (auto s: kw) keywords_.insert(s);
-    const char *types[] = {
-        "int","long","short","char","signed","unsigned","float","double","void",
-        "bool","wchar_t","size_t","ptrdiff_t","uint8_t","uint16_t","uint32_t","uint64_t",
-        "int8_t","int16_t","int32_t","int64_t"
-    };
-    for (auto s: types) types_.insert(s);
+	const char *kw[] = {
+		"if", "else", "for", "while", "do", "switch", "case", "default", "break", "continue",
+		"return", "goto", "struct", "class", "namespace", "using", "template", "typename",
+		"public", "private", "protected", "virtual", "override", "const", "constexpr", "auto",
+		"static", "inline", "operator", "new", "delete", "try", "catch", "throw", "friend",
+		"enum", "union", "extern", "volatile", "mutable", "noexcept", "sizeof", "this"
+	};
+	for (auto s: kw)
+		keywords_.insert(s);
+	const char *types[] = {
+		"int", "long", "short", "char", "signed", "unsigned", "float", "double", "void",
+		"bool", "wchar_t", "size_t", "ptrdiff_t", "uint8_t", "uint16_t", "uint32_t", "uint64_t",
+		"int8_t", "int16_t", "int32_t", "int64_t"
+	};
+	for (auto s: types)
+		types_.insert(s);
 }
 
-bool CppHighlighter::is_ident_start(char c) { return std::isalpha(static_cast<unsigned char>(c)) || c == '_'; }
-bool CppHighlighter::is_ident_char(char c) { return std::isalnum(static_cast<unsigned char>(c)) || c == '_'; }
 
-void CppHighlighter::HighlightLine(const Buffer &buf, int row, std::vector<HighlightSpan> &out) const
+bool
+CppHighlighter::is_ident_start(char c)
 {
-    // Stateless entry simply delegates to stateful with a clean previous state
-    StatefulHighlighter::LineState prev;
-    (void)HighlightLineStateful(buf, row, prev, out);
+	return std::isalpha(static_cast<unsigned char>(c)) || c == '_';
 }
 
-StatefulHighlighter::LineState CppHighlighter::HighlightLineStateful(const Buffer &buf,
-                                    int row,
-                                    const LineState &prev,
-                                    std::vector<HighlightSpan> &out) const
+
+bool
+CppHighlighter::is_ident_char(char c)
 {
-    const auto &rows = buf.Rows();
-    StatefulHighlighter::LineState state = prev;
-    if (row < 0 || static_cast<std::size_t>(row) >= rows.size()) return state;
-    std::string s = static_cast<std::string>(rows[static_cast<std::size_t>(row)]);
-    if (s.empty()) return state;
-
-    auto push = [&](int a, int b, TokenKind k){ if (b> a) out.push_back({a,b,k}); };
-    int n = static_cast<int>(s.size());
-    int bol = 0; while (bol < n && (s[bol] == ' ' || s[bol] == '\t')) ++bol;
-    int i = 0;
-
-    // Continue multi-line raw string from previous line
-    if (state.in_raw_string) {
-        std::string needle = ")" + state.raw_delim + "\"";
-        auto pos = s.find(needle);
-        if (pos == std::string::npos) {
-            push(0, n, TokenKind::String);
-            state.in_raw_string = true;
-            return state;
-        } else {
-            int end = static_cast<int>(pos + needle.size());
-            push(0, end, TokenKind::String);
-            i = end;
-            state.in_raw_string = false;
-            state.raw_delim.clear();
-        }
-    }
-
-    // Continue multi-line block comment from previous line
-    if (state.in_block_comment) {
-        int j = i;
-        while (i + 1 < n) {
-            if (s[i] == '*' && s[i+1] == '/') { i += 2; push(j, i, TokenKind::Comment); state.in_block_comment = false; break; }
-            ++i;
-        }
-        if (state.in_block_comment) { push(j, n, TokenKind::Comment); return state; }
-    }
-
-    while (i < n) {
-        char c = s[i];
-        // Preprocessor at beginning of line (after leading whitespace)
-        if (i == bol && c == '#') { push(0, n, TokenKind::Preproc); break; }
-
-        // Whitespace
-        if (c == ' ' || c == '\t') {
-            int j = i+1; while (j < n && (s[j] == ' ' || s[j] == '\t')) ++j; push(i,j,TokenKind::Whitespace); i=j; continue;
-        }
-
-        // Line comment
-        if (c == '/' && i+1 < n && s[i+1] == '/') { push(i, n, TokenKind::Comment); break; }
-
-        // Block comment
-        if (c == '/' && i+1 < n && s[i+1] == '*') {
-            int j = i+2;
-            bool closed = false;
-            while (j + 1 <= n) {
-                if (j + 1 < n && s[j] == '*' && s[j+1] == '/') { j += 2; closed = true; break; }
-                ++j;
-            }
-            if (closed) { push(i, j, TokenKind::Comment); i = j; continue; }
-            // Spill to next lines
-            push(i, n, TokenKind::Comment);
-            state.in_block_comment = true;
-            return state;
-        }
-
-        // Raw string start: very simple detection: R"delim(
-        if (c == 'R' && i+1 < n && s[i+1] == '"') {
-            int k = i + 2;
-            std::string delim;
-            while (k < n && s[k] != '(') { delim.push_back(s[k]); ++k; }
-            if (k < n && s[k] == '(') {
-                int body_start = k + 1;
-                std::string needle = ")" + delim + "\"";
-                auto pos = s.find(needle, static_cast<std::size_t>(body_start));
-                if (pos == std::string::npos) {
-                    push(i, n, TokenKind::String);
-                    state.in_raw_string = true;
-                    state.raw_delim = delim;
-                    return state;
-                } else {
-                    int end = static_cast<int>(pos + needle.size());
-                    push(i, end, TokenKind::String);
-                    i = end;
-                    continue;
-                }
-            }
-            // If malformed, just treat 'R' as identifier fallback
-        }
-
-        // Regular string literal
-        if (c == '"') {
-            int j = i+1; bool esc=false; while (j < n) { char d = s[j++]; if (esc) { esc=false; continue; } if (d == '\\') { esc=true; continue; } if (d == '"') break; }
-            push(i, j, TokenKind::String); i = j; continue;
-        }
-
-        // Char literal
-        if (c == '\'') {
-            int j = i+1; bool esc=false; while (j < n) { char d = s[j++]; if (esc) { esc=false; continue; } if (d == '\\') { esc=true; continue; } if (d == '\'') break; }
-            push(i, j, TokenKind::Char); i = j; continue;
-        }
-
-        // Number literal (simple)
-        if (is_digit(c) || (c == '.' && i+1 < n && is_digit(s[i+1]))) {
-            int j = i+1; while (j < n && (std::isalnum(static_cast<unsigned char>(s[j])) || s[j]=='.' || s[j]=='x' || s[j]=='X' || s[j]=='b' || s[j]=='B' || s[j]=='_')) ++j;
-            push(i, j, TokenKind::Number); i = j; continue;
-        }
-
-        // Identifier / keyword / type
-        if (is_ident_start(c)) {
-            int j = i+1; while (j < n && is_ident_char(s[j])) ++j; std::string id = s.substr(i, j-i);
-            TokenKind k = TokenKind::Identifier; if (keywords_.count(id)) k = TokenKind::Keyword; else if (types_.count(id)) k = TokenKind::Type; push(i, j, k); i = j; continue;
-        }
-
-        // Operators and punctuation (single char for now)
-        TokenKind kind = TokenKind::Operator;
-        if (std::ispunct(static_cast<unsigned char>(c)) && c != '_' && c != '#') {
-            if (c==';' || c==',' || c=='(' || c==')' || c=='{' || c=='}' || c=='[' || c==']') kind = TokenKind::Punctuation;
-            push(i, i+1, kind); ++i; continue;
-        }
-
-        // Fallback
-        push(i, i+1, TokenKind::Default); ++i;
-    }
-
-    return state;
+	return std::isalnum(static_cast<unsigned char>(c)) || c == '_';
 }
 
-} // namespace kte
+
+void
+CppHighlighter::HighlightLine(const Buffer &buf, int row, std::vector<HighlightSpan> &out) const
+{
+	// Stateless entry simply delegates to stateful with a clean previous state
+	StatefulHighlighter::LineState prev;
+	(void) HighlightLineStateful(buf, row, prev, out);
+}
+
+
+StatefulHighlighter::LineState
+CppHighlighter::HighlightLineStateful(const Buffer &buf,
+                                      int row,
+                                      const LineState &prev,
+                                      std::vector<HighlightSpan> &out) const
+{
+	const auto &rows                     = buf.Rows();
+	StatefulHighlighter::LineState state = prev;
+	if (row < 0 || static_cast<std::size_t>(row) >= rows.size())
+		return state;
+	std::string s = static_cast<std::string>(rows[static_cast<std::size_t>(row)]);
+	if (s.empty())
+		return state;
+
+	auto push = [&](int a, int b, TokenKind k) {
+		if (b > a)
+			out.push_back({a, b, k});
+	};
+	int n   = static_cast<int>(s.size());
+	int bol = 0;
+	while (bol < n && (s[bol] == ' ' || s[bol] == '\t'))
+		++bol;
+	int i = 0;
+
+	// Continue multi-line raw string from previous line
+	if (state.in_raw_string) {
+		std::string needle = ")" + state.raw_delim + "\"";
+		auto pos           = s.find(needle);
+		if (pos == std::string::npos) {
+			push(0, n, TokenKind::String);
+			state.in_raw_string = true;
+			return state;
+		} else {
+			int end = static_cast<int>(pos + needle.size());
+			push(0, end, TokenKind::String);
+			i                   = end;
+			state.in_raw_string = false;
+			state.raw_delim.clear();
+		}
+	}
+
+	// Continue multi-line block comment from previous line
+	if (state.in_block_comment) {
+		int j = i;
+		while (i + 1 < n) {
+			if (s[i] == '*' && s[i + 1] == '/') {
+				i += 2;
+				push(j, i, TokenKind::Comment);
+				state.in_block_comment = false;
+				break;
+			}
+			++i;
+		}
+		if (state.in_block_comment) {
+			push(j, n, TokenKind::Comment);
+			return state;
+		}
+	}
+
+	while (i < n) {
+		char c = s[i];
+		// Preprocessor at beginning of line (after leading whitespace)
+		if (i == bol && c == '#') {
+			push(0, n, TokenKind::Preproc);
+			break;
+		}
+
+		// Whitespace
+		if (c == ' ' || c == '\t') {
+			int j = i + 1;
+			while (j < n && (s[j] == ' ' || s[j] == '\t'))
+				++j;
+			push(i, j, TokenKind::Whitespace);
+			i = j;
+			continue;
+		}
+
+		// Line comment
+		if (c == '/' && i + 1 < n && s[i + 1] == '/') {
+			push(i, n, TokenKind::Comment);
+			break;
+		}
+
+		// Block comment
+		if (c == '/' && i + 1 < n && s[i + 1] == '*') {
+			int j       = i + 2;
+			bool closed = false;
+			while (j + 1 <= n) {
+				if (j + 1 < n && s[j] == '*' && s[j + 1] == '/') {
+					j += 2;
+					closed = true;
+					break;
+				}
+				++j;
+			}
+			if (closed) {
+				push(i, j, TokenKind::Comment);
+				i = j;
+				continue;
+			}
+			// Spill to next lines
+			push(i, n, TokenKind::Comment);
+			state.in_block_comment = true;
+			return state;
+		}
+
+		// Raw string start: very simple detection: R"delim(
+		if (c == 'R' && i + 1 < n && s[i + 1] == '"') {
+			int k = i + 2;
+			std::string delim;
+			while (k < n && s[k] != '(') {
+				delim.push_back(s[k]);
+				++k;
+			}
+			if (k < n && s[k] == '(') {
+				int body_start     = k + 1;
+				std::string needle = ")" + delim + "\"";
+				auto pos           = s.find(needle, static_cast<std::size_t>(body_start));
+				if (pos == std::string::npos) {
+					push(i, n, TokenKind::String);
+					state.in_raw_string = true;
+					state.raw_delim     = delim;
+					return state;
+				} else {
+					int end = static_cast<int>(pos + needle.size());
+					push(i, end, TokenKind::String);
+					i = end;
+					continue;
+				}
+			}
+			// If malformed, just treat 'R' as identifier fallback
+		}
+
+		// Regular string literal
+		if (c == '"') {
+			int j    = i + 1;
+			bool esc = false;
+			while (j < n) {
+				char d = s[j++];
+				if (esc) {
+					esc = false;
+					continue;
+				}
+				if (d == '\\') {
+					esc = true;
+					continue;
+				}
+				if (d == '"')
+					break;
+			}
+			push(i, j, TokenKind::String);
+			i = j;
+			continue;
+		}
+
+		// Char literal
+		if (c == '\'') {
+			int j    = i + 1;
+			bool esc = false;
+			while (j < n) {
+				char d = s[j++];
+				if (esc) {
+					esc = false;
+					continue;
+				}
+				if (d == '\\') {
+					esc = true;
+					continue;
+				}
+				if (d == '\'')
+					break;
+			}
+			push(i, j, TokenKind::Char);
+			i = j;
+			continue;
+		}
+
+		// Number literal (simple)
+		if (is_digit(c) || (c == '.' && i + 1 < n && is_digit(s[i + 1]))) {
+			int j = i + 1;
+			while (j < n && (std::isalnum(static_cast<unsigned char>(s[j])) || s[j] == '.' || s[j] == 'x' ||
+			                 s[j] == 'X' || s[j] == 'b' || s[j] == 'B' || s[j] == '_'))
+				++j;
+			push(i, j, TokenKind::Number);
+			i = j;
+			continue;
+		}
+
+		// Identifier / keyword / type
+		if (is_ident_start(c)) {
+			int j = i + 1;
+			while (j < n && is_ident_char(s[j]))
+				++j;
+			std::string id = s.substr(i, j - i);
+			TokenKind k    = TokenKind::Identifier;
+			if (keywords_.count(id))
+				k = TokenKind::Keyword;
+			else if (types_.count(id))
+				k = TokenKind::Type;
+			push(i, j, k);
+			i = j;
+			continue;
+		}
+
+		// Operators and punctuation (single char for now)
+		TokenKind kind = TokenKind::Operator;
+		if (std::ispunct(static_cast<unsigned char>(c)) && c != '_' && c != '#') {
+			if (c == ';' || c == ',' || c == '(' || c == ')' || c == '{' || c == '}' || c == '[' || c ==
+			    ']')
+				kind = TokenKind::Punctuation;
+			push(i, i + 1, kind);
+			++i;
+			continue;
+		}
+
+		// Fallback
+		push(i, i + 1, TokenKind::Default);
+		++i;
+	}
+
+	return state;
+}
+} // namespace kte
\ No newline at end of file
diff --git a/CppHighlighter.h b/CppHighlighter.h
index 9b63bff..10a3680 100644
--- a/CppHighlighter.h
+++ b/CppHighlighter.h
@@ -11,24 +11,25 @@
 class Buffer;
 
 namespace kte {
-
 class CppHighlighter final : public StatefulHighlighter {
 public:
-    CppHighlighter();
-    ~CppHighlighter() override = default;
+	CppHighlighter();
 
-    void HighlightLine(const Buffer &buf, int row, std::vector<HighlightSpan> &out) const override;
-    LineState HighlightLineStateful(const Buffer &buf,
-                                    int row,
-                                    const LineState &prev,
-                                    std::vector<HighlightSpan> &out) const override;
+	~CppHighlighter() override = default;
+
+	void HighlightLine(const Buffer &buf, int row, std::vector<HighlightSpan> &out) const override;
+
+	LineState HighlightLineStateful(const Buffer &buf,
+	                                int row,
+	                                const LineState &prev,
+	                                std::vector<HighlightSpan> &out) const override;
 
 private:
-    std::unordered_set<std::string> keywords_;
-    std::unordered_set<std::string> types_;
+	std::unordered_set<std::string> keywords_;
+	std::unordered_set<std::string> types_;
 
-    static bool is_ident_start(char c);
-    static bool is_ident_char(char c);
+	static bool is_ident_start(char c);
+
+	static bool is_ident_char(char c);
 };
-
-} // namespace kte
+} // namespace kte
\ No newline at end of file
diff --git a/Editor.cc b/Editor.cc
index 1aa82f2..1fc9923 100644
--- a/Editor.cc
+++ b/Editor.cc
@@ -148,104 +148,107 @@ Editor::OpenFile(const std::string &path, std::string &err)
 {
 	// If there is exactly one unnamed, empty, clean buffer, reuse it instead
 	// of creating a new one.
- if (buffers_.size() == 1) {
-        Buffer &cur                  = buffers_[curbuf_];
-        const bool unnamed           = cur.Filename().empty() && !cur.IsFileBacked();
-        const bool clean             = !cur.Dirty();
-        const auto &rows             = cur.Rows();
-        const bool rows_empty        = rows.empty();
-        const bool single_empty_line = (!rows.empty() && rows.size() == 1 && rows[0].size() == 0);
-        if (unnamed && clean && (rows_empty || single_empty_line)) {
-            bool ok = cur.OpenFromFile(path, err);
-            if (!ok) return false;
-            // Setup highlighting using registry (extension + shebang)
-            cur.EnsureHighlighter();
-            std::string first = "";
-            const auto &rows = cur.Rows();
-            if (!rows.empty()) first = static_cast<std::string>(rows[0]);
-            std::string ft = kte::HighlighterRegistry::DetectForPath(path, first);
-            if (!ft.empty()) {
-                cur.SetFiletype(ft);
-                cur.SetSyntaxEnabled(true);
-                if (auto *eng = cur.Highlighter()) {
-                    eng->SetHighlighter(kte::HighlighterRegistry::CreateFor(ft));
-                    eng->InvalidateFrom(0);
-                }
-            } else {
-                cur.SetFiletype("");
-                cur.SetSyntaxEnabled(true);
-                if (auto *eng = cur.Highlighter()) {
-                    eng->SetHighlighter(std::make_unique<kte::NullHighlighter>());
-                    eng->InvalidateFrom(0);
-                }
-            }
-            return true;
-        }
-    }
+	if (buffers_.size() == 1) {
+		Buffer &cur                  = buffers_[curbuf_];
+		const bool unnamed           = cur.Filename().empty() && !cur.IsFileBacked();
+		const bool clean             = !cur.Dirty();
+		const auto &rows             = cur.Rows();
+		const bool rows_empty        = rows.empty();
+		const bool single_empty_line = (!rows.empty() && rows.size() == 1 && rows[0].size() == 0);
+		if (unnamed && clean && (rows_empty || single_empty_line)) {
+			bool ok = cur.OpenFromFile(path, err);
+			if (!ok)
+				return false;
+			// Setup highlighting using registry (extension + shebang)
+			cur.EnsureHighlighter();
+			std::string first = "";
+			const auto &rows  = cur.Rows();
+			if (!rows.empty())
+				first = static_cast<std::string>(rows[0]);
+			std::string ft = kte::HighlighterRegistry::DetectForPath(path, first);
+			if (!ft.empty()) {
+				cur.SetFiletype(ft);
+				cur.SetSyntaxEnabled(true);
+				if (auto *eng = cur.Highlighter()) {
+					eng->SetHighlighter(kte::HighlighterRegistry::CreateFor(ft));
+					eng->InvalidateFrom(0);
+				}
+			} else {
+				cur.SetFiletype("");
+				cur.SetSyntaxEnabled(true);
+				if (auto *eng = cur.Highlighter()) {
+					eng->SetHighlighter(std::make_unique<kte::NullHighlighter>());
+					eng->InvalidateFrom(0);
+				}
+			}
+			return true;
+		}
+	}
 
-    Buffer b;
-    if (!b.OpenFromFile(path, err)) {
-        return false;
-    }
-    // Initialize syntax highlighting by extension + shebang via registry (v2)
-    b.EnsureHighlighter();
-    std::string first = "";
-    {
-        const auto &rows = b.Rows();
-        if (!rows.empty()) first = static_cast<std::string>(rows[0]);
-    }
-    std::string ft = kte::HighlighterRegistry::DetectForPath(path, first);
-    if (!ft.empty()) {
-        b.SetFiletype(ft);
-        b.SetSyntaxEnabled(true);
-        if (auto *eng = b.Highlighter()) {
-            eng->SetHighlighter(kte::HighlighterRegistry::CreateFor(ft));
-            eng->InvalidateFrom(0);
-        }
-    } else {
-        b.SetFiletype("");
-        b.SetSyntaxEnabled(true);
-        if (auto *eng = b.Highlighter()) {
-            eng->SetHighlighter(std::make_unique<kte::NullHighlighter>());
-            eng->InvalidateFrom(0);
-        }
-    }
-    // Add as a new buffer and switch to it
-    std::size_t idx = AddBuffer(std::move(b));
-    SwitchTo(idx);
-    return true;
+	Buffer b;
+	if (!b.OpenFromFile(path, err)) {
+		return false;
+	}
+	// Initialize syntax highlighting by extension + shebang via registry (v2)
+	b.EnsureHighlighter();
+	std::string first = "";
+	{
+		const auto &rows = b.Rows();
+		if (!rows.empty())
+			first = static_cast<std::string>(rows[0]);
+	}
+	std::string ft = kte::HighlighterRegistry::DetectForPath(path, first);
+	if (!ft.empty()) {
+		b.SetFiletype(ft);
+		b.SetSyntaxEnabled(true);
+		if (auto *eng = b.Highlighter()) {
+			eng->SetHighlighter(kte::HighlighterRegistry::CreateFor(ft));
+			eng->InvalidateFrom(0);
+		}
+	} else {
+		b.SetFiletype("");
+		b.SetSyntaxEnabled(true);
+		if (auto *eng = b.Highlighter()) {
+			eng->SetHighlighter(std::make_unique<kte::NullHighlighter>());
+			eng->InvalidateFrom(0);
+		}
+	}
+	// Add as a new buffer and switch to it
+	std::size_t idx = AddBuffer(std::move(b));
+	SwitchTo(idx);
+	return true;
 }
 
 
 bool
 Editor::SwitchTo(std::size_t index)
 {
-    if (index >= buffers_.size()) {
-        return false;
-    }
-    curbuf_ = index;
-    // Robustness: ensure a valid highlighter is installed when switching buffers
-    Buffer &b = buffers_[curbuf_];
-    if (b.SyntaxEnabled()) {
-        b.EnsureHighlighter();
-        if (auto *eng = b.Highlighter()) {
-            if (!eng->HasHighlighter()) {
-                // Try to set based on existing filetype; fall back to NullHighlighter
-                if (!b.Filetype().empty()) {
-                    auto hl = kte::HighlighterRegistry::CreateFor(b.Filetype());
-                    if (hl) {
-                        eng->SetHighlighter(std::move(hl));
-                    } else {
-                        eng->SetHighlighter(std::make_unique<kte::NullHighlighter>());
-                    }
-                } else {
-                    eng->SetHighlighter(std::make_unique<kte::NullHighlighter>());
-                }
-                eng->InvalidateFrom(0);
-            }
-        }
-    }
-    return true;
+	if (index >= buffers_.size()) {
+		return false;
+	}
+	curbuf_ = index;
+	// Robustness: ensure a valid highlighter is installed when switching buffers
+	Buffer &b = buffers_[curbuf_];
+	if (b.SyntaxEnabled()) {
+		b.EnsureHighlighter();
+		if (auto *eng = b.Highlighter()) {
+			if (!eng->HasHighlighter()) {
+				// Try to set based on existing filetype; fall back to NullHighlighter
+				if (!b.Filetype().empty()) {
+					auto hl = kte::HighlighterRegistry::CreateFor(b.Filetype());
+					if (hl) {
+						eng->SetHighlighter(std::move(hl));
+					} else {
+						eng->SetHighlighter(std::make_unique<kte::NullHighlighter>());
+					}
+				} else {
+					eng->SetHighlighter(std::make_unique<kte::NullHighlighter>());
+				}
+				eng->InvalidateFrom(0);
+			}
+		}
+	}
+	return true;
 }
 
 
@@ -281,4 +284,4 @@ Editor::Reset()
 	quit_confirm_pending_ = false;
 	buffers_.clear();
 	curbuf_ = 0;
-}
+}
\ No newline at end of file
diff --git a/GUIConfig.cc b/GUIConfig.cc
index 9820ef0..ef0c913 100644
--- a/GUIConfig.cc
+++ b/GUIConfig.cc
@@ -102,27 +102,27 @@ GUIConfig::LoadFromFile(const std::string &path)
 			if (v > 0.0f) {
 				font_size = v;
 			}
-        } else if (key == "theme") {
-            theme = val;
-        } else if (key == "background" || key == "bg") {
-            std::string v = val;
-            std::transform(v.begin(), v.end(), v.begin(), [](unsigned char c) {
-                return (char) std::tolower(c);
-            });
-            if (v == "light" || v == "dark")
-                background = v;
-        } else if (key == "syntax") {
-            std::string v = val;
-            std::transform(v.begin(), v.end(), v.begin(), [](unsigned char c) {
-                return (char) std::tolower(c);
-            });
-            if (v == "1" || v == "on" || v == "true" || v == "yes") {
-                syntax = true;
-            } else if (v == "0" || v == "off" || v == "false" || v == "no") {
-                syntax = false;
-            }
-        }
-    }
+		} else if (key == "theme") {
+			theme = val;
+		} else if (key == "background" || key == "bg") {
+			std::string v = val;
+			std::transform(v.begin(), v.end(), v.begin(), [](unsigned char c) {
+				return (char) std::tolower(c);
+			});
+			if (v == "light" || v == "dark")
+				background = v;
+		} else if (key == "syntax") {
+			std::string v = val;
+			std::transform(v.begin(), v.end(), v.begin(), [](unsigned char c) {
+				return (char) std::tolower(c);
+			});
+			if (v == "1" || v == "on" || v == "true" || v == "yes") {
+				syntax = true;
+			} else if (v == "0" || v == "off" || v == "false" || v == "no") {
+				syntax = false;
+			}
+		}
+	}
 
-    return true;
-}
+	return true;
+}
\ No newline at end of file
diff --git a/GUIConfig.h b/GUIConfig.h
index 63799e1..61da5fa 100644
--- a/GUIConfig.h
+++ b/GUIConfig.h
@@ -12,18 +12,18 @@
 
 class GUIConfig {
 public:
-    bool fullscreen   = false;
-    int columns       = 80;
-    int rows          = 42;
-    float font_size   = (float) KTE_FONT_SIZE;
-    std::string theme = "nord";
-    // Background mode for themes that support light/dark variants
-    // Values: "dark" (default), "light"
-    std::string background = "dark";
+	bool fullscreen   = false;
+	int columns       = 80;
+	int rows          = 42;
+	float font_size   = (float) KTE_FONT_SIZE;
+	std::string theme = "nord";
+	// Background mode for themes that support light/dark variants
+	// Values: "dark" (default), "light"
+	std::string background = "dark";
 
-    // Default syntax highlighting state for GUI (kge): on/off
-    // Accepts: on/off/true/false/yes/no/1/0 in the ini file.
-    bool syntax = true; // default: enabled
+	// Default syntax highlighting state for GUI (kge): on/off
+	// Accepts: on/off/true/false/yes/no/1/0 in the ini file.
+	bool syntax = true; // default: enabled
 
 	// Load from default path: $HOME/.config/kte/kge.ini
 	static GUIConfig Load();
@@ -32,4 +32,4 @@ public:
 	bool LoadFromFile(const std::string &path);
 };
 
-#endif // KTE_GUI_CONFIG_H
+#endif // KTE_GUI_CONFIG_H
\ No newline at end of file
diff --git a/GUIFrontend.cc b/GUIFrontend.cc
index afd0dcc..597d81c 100644
--- a/GUIFrontend.cc
+++ b/GUIFrontend.cc
@@ -108,42 +108,44 @@ GUIFrontend::Init(Editor &ed)
 	(void) io;
 	ImGui::StyleColorsDark();
 
- // Apply background mode and selected theme (default: Nord). Can be changed at runtime via commands.
- if (cfg.background == "light")
-     kte::SetBackgroundMode(kte::BackgroundMode::Light);
- else
-     kte::SetBackgroundMode(kte::BackgroundMode::Dark);
- kte::ApplyThemeByName(cfg.theme);
+	// Apply background mode and selected theme (default: Nord). Can be changed at runtime via commands.
+	if (cfg.background == "light")
+		kte::SetBackgroundMode(kte::BackgroundMode::Light);
+	else
+		kte::SetBackgroundMode(kte::BackgroundMode::Dark);
+	kte::ApplyThemeByName(cfg.theme);
 
- // Apply default syntax highlighting preference from GUI config to the current buffer
- if (Buffer *b = ed.CurrentBuffer()) {
-     if (cfg.syntax) {
-         b->SetSyntaxEnabled(true);
-         // Ensure a highlighter is available if possible
-         b->EnsureHighlighter();
-         if (auto *eng = b->Highlighter()) {
-             if (!eng->HasHighlighter()) {
-                 // Try detect from filename and first line; fall back to cpp or existing filetype
-                 std::string first_line;
-                 const auto &rows = b->Rows();
-                 if (!rows.empty()) first_line = static_cast<std::string>(rows[0]);
-                 std::string ft = kte::HighlighterRegistry::DetectForPath(b->Filename(), first_line);
-                 if (!ft.empty()) {
-                     eng->SetHighlighter(kte::HighlighterRegistry::CreateFor(ft));
-                     b->SetFiletype(ft);
-                     eng->InvalidateFrom(0);
-                 } else {
-                     // Unknown/unsupported -> install a null highlighter to keep syntax enabled
-                     eng->SetHighlighter(std::make_unique<kte::NullHighlighter>());
-                     b->SetFiletype("");
-                     eng->InvalidateFrom(0);
-                 }
-             }
-         }
-     } else {
-         b->SetSyntaxEnabled(false);
-     }
- }
+	// Apply default syntax highlighting preference from GUI config to the current buffer
+	if (Buffer *b = ed.CurrentBuffer()) {
+		if (cfg.syntax) {
+			b->SetSyntaxEnabled(true);
+			// Ensure a highlighter is available if possible
+			b->EnsureHighlighter();
+			if (auto *eng = b->Highlighter()) {
+				if (!eng->HasHighlighter()) {
+					// Try detect from filename and first line; fall back to cpp or existing filetype
+					std::string first_line;
+					const auto &rows = b->Rows();
+					if (!rows.empty())
+						first_line = static_cast<std::string>(rows[0]);
+					std::string ft = kte::HighlighterRegistry::DetectForPath(
+						b->Filename(), first_line);
+					if (!ft.empty()) {
+						eng->SetHighlighter(kte::HighlighterRegistry::CreateFor(ft));
+						b->SetFiletype(ft);
+						eng->InvalidateFrom(0);
+					} else {
+						// Unknown/unsupported -> install a null highlighter to keep syntax enabled
+						eng->SetHighlighter(std::make_unique<kte::NullHighlighter>());
+						b->SetFiletype("");
+						eng->InvalidateFrom(0);
+					}
+				}
+			}
+		} else {
+			b->SetSyntaxEnabled(false);
+		}
+	}
 
 	if (!ImGui_ImplSDL2_InitForOpenGL(window_, gl_ctx_))
 		return false;
@@ -316,4 +318,4 @@ GUIFrontend::LoadGuiFont_(const char * /*path*/, float size_px)
 }
 
 
-// No runtime font reload or system font resolution in this simplified build.
+// No runtime font reload or system font resolution in this simplified build.
\ No newline at end of file
diff --git a/GUIRenderer.cc b/GUIRenderer.cc
index 9ccf1fa..a607235 100644
--- a/GUIRenderer.cc
+++ b/GUIRenderer.cc
@@ -139,29 +139,29 @@ GUIRenderer::Draw(Editor &ed)
 				vis_rows = 1;
 			long last_row = first_row + vis_rows - 1;
 
-            if (!forced_scroll) {
-                long cyr = static_cast<long>(cy);
-                if (cyr < first_row || cyr > last_row) {
-                    float target = (static_cast<float>(cyr) - std::max(0L, vis_rows / 2)) * row_h;
-                    float max_y  = ImGui::GetScrollMaxY();
-                    if (target < 0.f)
-                        target = 0.f;
-                    if (max_y >= 0.f && target > max_y)
-                        target = max_y;
-                    ImGui::SetScrollY(target);
-                    // refresh local variables
-                    scroll_y  = ImGui::GetScrollY();
-                    first_row = static_cast<long>(scroll_y / row_h);
-                    last_row  = first_row + vis_rows - 1;
-                }
-            }
-            // Phase 3: prefetch visible viewport highlights and warm around in background
-            if (buf->SyntaxEnabled() && buf->Highlighter() && buf->Highlighter()->HasHighlighter()) {
-                int fr = static_cast<int>(std::max(0L, first_row));
-                int rc = static_cast<int>(std::max(1L, vis_rows));
-                buf->Highlighter()->PrefetchViewport(*buf, fr, rc, buf->Version());
-            }
-        }
+			if (!forced_scroll) {
+				long cyr = static_cast<long>(cy);
+				if (cyr < first_row || cyr > last_row) {
+					float target = (static_cast<float>(cyr) - std::max(0L, vis_rows / 2)) * row_h;
+					float max_y  = ImGui::GetScrollMaxY();
+					if (target < 0.f)
+						target = 0.f;
+					if (max_y >= 0.f && target > max_y)
+						target = max_y;
+					ImGui::SetScrollY(target);
+					// refresh local variables
+					scroll_y  = ImGui::GetScrollY();
+					first_row = static_cast<long>(scroll_y / row_h);
+					last_row  = first_row + vis_rows - 1;
+				}
+			}
+			// Phase 3: prefetch visible viewport highlights and warm around in background
+			if (buf->SyntaxEnabled() && buf->Highlighter() && buf->Highlighter()->HasHighlighter()) {
+				int fr = static_cast<int>(std::max(0L, first_row));
+				int rc = static_cast<int>(std::max(1L, vis_rows));
+				buf->Highlighter()->PrefetchViewport(*buf, fr, rc, buf->Version());
+			}
+		}
 		// Handle mouse click before rendering to avoid dependent on drawn items
 		if (ImGui::IsWindowHovered() && ImGui::IsMouseClicked(ImGuiMouseButton_Left)) {
 			ImVec2 mp = ImGui::GetIO().MousePos;
@@ -329,50 +329,56 @@ GUIRenderer::Draw(Editor &ed)
 					ImGui::GetWindowDrawList()->AddRectFilled(p0, p1, col);
 				}
 			}
-   // Emit entire line to an expanded buffer (tabs -> spaces)
-   for (std::size_t src = 0; src < line.size(); ++src) {
-       char c = line[src];
-       if (c == '\t') {
-           std::size_t adv = (tabw - (rx_abs_draw % tabw));
-           expanded.append(adv, ' ');
-           rx_abs_draw += adv;
-       } else {
-           expanded.push_back(c);
-           rx_abs_draw += 1;
-       }
-   }
+			// Emit entire line to an expanded buffer (tabs -> spaces)
+			for (std::size_t src = 0; src < line.size(); ++src) {
+				char c = line[src];
+				if (c == '\t') {
+					std::size_t adv = (tabw - (rx_abs_draw % tabw));
+					expanded.append(adv, ' ');
+					rx_abs_draw += adv;
+				} else {
+					expanded.push_back(c);
+					rx_abs_draw += 1;
+				}
+			}
 
-   // Draw syntax-colored runs (text above background highlights)
-   if (buf->SyntaxEnabled() && buf->Highlighter() && buf->Highlighter()->HasHighlighter()) {
-       const kte::LineHighlight &lh = buf->Highlighter()->GetLine(*buf, static_cast<int>(i), buf->Version());
-       // Helper to convert a src column to expanded rx position
-       auto src_to_rx_full = [&](std::size_t sidx) -> std::size_t {
-           std::size_t rx = 0;
-           for (std::size_t k = 0; k < sidx && k < line.size(); ++k) {
-               rx += (line[k] == '\t') ? (tabw - (rx % tabw)) : 1;
-           }
-           return rx;
-       };
-       for (const auto &sp: lh.spans) {
-           std::size_t rx_s = src_to_rx_full(static_cast<std::size_t>(std::max(0, sp.col_start)));
-           std::size_t rx_e = src_to_rx_full(static_cast<std::size_t>(std::max(sp.col_start, sp.col_end)));
-           if (rx_e <= coloffs_now)
-               continue;
-           std::size_t vx0 = (rx_s > coloffs_now) ? (rx_s - coloffs_now) : 0;
-           std::size_t vx1 = (rx_e > coloffs_now) ? (rx_e - coloffs_now) : 0;
-           if (vx0 >= expanded.size()) continue;
-           vx1 = std::min<std::size_t>(vx1, expanded.size());
-           if (vx1 <= vx0) continue;
-           ImU32 col = ImGui::GetColorU32(kte::SyntaxInk(sp.kind));
-           ImVec2 p = ImVec2(line_pos.x + static_cast<float>(vx0) * space_w, line_pos.y);
-           ImGui::GetWindowDrawList()->AddText(p, col, expanded.c_str() + vx0, expanded.c_str() + vx1);
-       }
-       // We drew text via draw list (no layout advance). Manually advance the cursor to the next line.
-       ImGui::SetCursorScreenPos(ImVec2(line_pos.x, line_pos.y + line_h));
-   } else {
-       // No syntax: draw as one run
-       ImGui::TextUnformatted(expanded.c_str());
-   }
+			// Draw syntax-colored runs (text above background highlights)
+			if (buf->SyntaxEnabled() && buf->Highlighter() && buf->Highlighter()->HasHighlighter()) {
+				const kte::LineHighlight &lh = buf->Highlighter()->GetLine(
+					*buf, static_cast<int>(i), buf->Version());
+				// Helper to convert a src column to expanded rx position
+				auto src_to_rx_full = [&](std::size_t sidx) -> std::size_t {
+					std::size_t rx = 0;
+					for (std::size_t k = 0; k < sidx && k < line.size(); ++k) {
+						rx += (line[k] == '\t') ? (tabw - (rx % tabw)) : 1;
+					}
+					return rx;
+				};
+				for (const auto &sp: lh.spans) {
+					std::size_t rx_s = src_to_rx_full(
+						static_cast<std::size_t>(std::max(0, sp.col_start)));
+					std::size_t rx_e = src_to_rx_full(
+						static_cast<std::size_t>(std::max(sp.col_start, sp.col_end)));
+					if (rx_e <= coloffs_now)
+						continue;
+					std::size_t vx0 = (rx_s > coloffs_now) ? (rx_s - coloffs_now) : 0;
+					std::size_t vx1 = (rx_e > coloffs_now) ? (rx_e - coloffs_now) : 0;
+					if (vx0 >= expanded.size())
+						continue;
+					vx1 = std::min<std::size_t>(vx1, expanded.size());
+					if (vx1 <= vx0)
+						continue;
+					ImU32 col = ImGui::GetColorU32(kte::SyntaxInk(sp.kind));
+					ImVec2 p  = ImVec2(line_pos.x + static_cast<float>(vx0) * space_w, line_pos.y);
+					ImGui::GetWindowDrawList()->AddText(
+						p, col, expanded.c_str() + vx0, expanded.c_str() + vx1);
+				}
+				// We drew text via draw list (no layout advance). Manually advance the cursor to the next line.
+				ImGui::SetCursorScreenPos(ImVec2(line_pos.x, line_pos.y + line_h));
+			} else {
+				// No syntax: draw as one run
+				ImGui::TextUnformatted(expanded.c_str());
+			}
 
 			// Draw a visible cursor indicator on the current line
 			if (i == cy) {
@@ -761,4 +767,4 @@ GUIRenderer::Draw(Editor &ed)
 			ed.SetFilePickerVisible(false);
 		}
 	}
-}
+}
\ No newline at end of file
diff --git a/GUITheme.h b/GUITheme.h
index 1606c4a..9b41cdb 100644
--- a/GUITheme.h
+++ b/GUITheme.h
@@ -10,16 +10,17 @@
 #include <cctype>
 
 // Small helper to convert packed RGB (0xRRGGBB) + optional alpha to ImVec4
-static inline ImVec4 RGBA(unsigned int rgb, float a = 1.0f)
+static inline ImVec4
+RGBA(unsigned int rgb, float a = 1.0f)
 {
-    const float r = static_cast<float>((rgb >> 16) & 0xFF) / 255.0f;
-    const float g = static_cast<float>((rgb >> 8) & 0xFF) / 255.0f;
-    const float b = static_cast<float>(rgb & 0xFF) / 255.0f;
-    return ImVec4(r, g, b, a);
+	const float r = static_cast<float>((rgb >> 16) & 0xFF) / 255.0f;
+	const float g = static_cast<float>((rgb >> 8) & 0xFF) / 255.0f;
+	const float b = static_cast<float>(rgb & 0xFF) / 255.0f;
+	return ImVec4(r, g, b, a);
 }
 
-namespace kte {
 
+namespace kte {
 // Background mode selection for light/dark palettes
 enum class BackgroundMode { Light, Dark };
 
@@ -28,20 +29,21 @@ static inline BackgroundMode gBackgroundMode = BackgroundMode::Dark;
 
 // Basic theme identifier (kept minimal; some ids are aliases)
 enum class ThemeId {
-    EInk = 0,
-    GruvboxDarkMedium = 1,
-    GruvboxLightMedium = 1, // alias to unified gruvbox index
-    Nord = 2,
-    Plan9 = 3,
-    Solarized = 4,
+	EInk = 0,
+	GruvboxDarkMedium = 1,
+	GruvboxLightMedium = 1, // alias to unified gruvbox index
+	Nord = 2,
+	Plan9 = 3,
+	Solarized = 4,
 };
 
 // Current theme tracking
-static inline ThemeId gCurrentTheme = ThemeId::Nord;
+static inline ThemeId gCurrentTheme          = ThemeId::Nord;
 static inline std::size_t gCurrentThemeIndex = 0;
 
 // Forward declarations for helpers used below
 static inline size_t ThemeIndexFromId(ThemeId id);
+
 static inline ThemeId ThemeIdFromIndex(size_t idx);
 
 // Helpers to set/query background mode
@@ -1098,18 +1100,18 @@ CurrentThemeName()
 static inline size_t
 ThemeIndexFromId(ThemeId id)
 {
- switch (id) {
- case ThemeId::EInk:
-     return 0;
- case ThemeId::GruvboxDarkMedium:
-     return 1;
- case ThemeId::Nord:
-     return 2;
- case ThemeId::Plan9:
-     return 3;
- case ThemeId::Solarized:
-     return 4;
- }
+	switch (id) {
+	case ThemeId::EInk:
+		return 0;
+	case ThemeId::GruvboxDarkMedium:
+		return 1;
+	case ThemeId::Nord:
+		return 2;
+	case ThemeId::Plan9:
+		return 3;
+	case ThemeId::Solarized:
+		return 4;
+	}
 	return 0;
 }
 
@@ -1132,29 +1134,46 @@ ThemeIdFromIndex(size_t idx)
 	}
 }
 
+
 // --- Syntax palette (v1): map TokenKind to ink color per current theme/background ---
-static inline ImVec4 SyntaxInk(TokenKind k)
+static inline ImVec4
+SyntaxInk(TokenKind k)
 {
-    // Basic palettes for dark/light backgrounds; tuned for Nord-ish defaults
-    const bool dark = (GetBackgroundMode() == BackgroundMode::Dark);
-    // Base text
-    ImVec4 def = dark ? RGBA(0xD8DEE9) : RGBA(0x2E3440);
-    switch (k) {
-        case TokenKind::Keyword:      return dark ? RGBA(0x81A1C1) : RGBA(0x5E81AC);
-        case TokenKind::Type:         return dark ? RGBA(0x8FBCBB) : RGBA(0x4C566A);
-        case TokenKind::String:       return dark ? RGBA(0xA3BE8C) : RGBA(0x6C8E5E);
-        case TokenKind::Char:         return dark ? RGBA(0xA3BE8C) : RGBA(0x6C8E5E);
-        case TokenKind::Comment:      return dark ? RGBA(0x616E88) : RGBA(0x7A869A);
-        case TokenKind::Number:       return dark ? RGBA(0xEBCB8B) : RGBA(0xB58900);
-        case TokenKind::Preproc:      return dark ? RGBA(0xD08770) : RGBA(0xAF3A03);
-        case TokenKind::Constant:     return dark ? RGBA(0xB48EAD) : RGBA(0x7B4B7F);
-        case TokenKind::Function:     return dark ? RGBA(0x88C0D0) : RGBA(0x3465A4);
-        case TokenKind::Operator:     return dark ? RGBA(0xECEFF4) : RGBA(0x2E3440);
-        case TokenKind::Punctuation:  return dark ? RGBA(0xECEFF4) : RGBA(0x2E3440);
-        case TokenKind::Identifier:   return def;
-        case TokenKind::Whitespace:   return def;
-        case TokenKind::Error:        return dark ? RGBA(0xBF616A) : RGBA(0xCC0000);
-        case TokenKind::Default:      default: return def;
-    }
+	// Basic palettes for dark/light backgrounds; tuned for Nord-ish defaults
+	const bool dark = (GetBackgroundMode() == BackgroundMode::Dark);
+	// Base text
+	ImVec4 def = dark ? RGBA(0xD8DEE9) : RGBA(0x2E3440);
+	switch (k) {
+	case TokenKind::Keyword:
+		return dark ? RGBA(0x81A1C1) : RGBA(0x5E81AC);
+	case TokenKind::Type:
+		return dark ? RGBA(0x8FBCBB) : RGBA(0x4C566A);
+	case TokenKind::String:
+		return dark ? RGBA(0xA3BE8C) : RGBA(0x6C8E5E);
+	case TokenKind::Char:
+		return dark ? RGBA(0xA3BE8C) : RGBA(0x6C8E5E);
+	case TokenKind::Comment:
+		return dark ? RGBA(0x616E88) : RGBA(0x7A869A);
+	case TokenKind::Number:
+		return dark ? RGBA(0xEBCB8B) : RGBA(0xB58900);
+	case TokenKind::Preproc:
+		return dark ? RGBA(0xD08770) : RGBA(0xAF3A03);
+	case TokenKind::Constant:
+		return dark ? RGBA(0xB48EAD) : RGBA(0x7B4B7F);
+	case TokenKind::Function:
+		return dark ? RGBA(0x88C0D0) : RGBA(0x3465A4);
+	case TokenKind::Operator:
+		return dark ? RGBA(0xECEFF4) : RGBA(0x2E3440);
+	case TokenKind::Punctuation:
+		return dark ? RGBA(0xECEFF4) : RGBA(0x2E3440);
+	case TokenKind::Identifier:
+		return def;
+	case TokenKind::Whitespace:
+		return def;
+	case TokenKind::Error:
+		return dark ? RGBA(0xBF616A) : RGBA(0xCC0000);
+	case TokenKind::Default: default:
+		return def;
+	}
 }
-} // namespace kte
+} // namespace kte
\ No newline at end of file
diff --git a/GoHighlighter.cc b/GoHighlighter.cc
index d63e240..6463c86 100644
--- a/GoHighlighter.cc
+++ b/GoHighlighter.cc
@@ -3,46 +3,155 @@
 #include <cctype>
 
 namespace kte {
+static void
+push(std::vector<HighlightSpan> &out, int a, int b, TokenKind k)
+{
+	if (b > a)
+		out.push_back({a, b, k});
+}
+
+
+static bool
+is_ident_start(char c)
+{
+	return std::isalpha(static_cast<unsigned char>(c)) || c == '_';
+}
+
+
+static bool
+is_ident_char(char c)
+{
+	return std::isalnum(static_cast<unsigned char>(c)) || c == '_';
+}
 
-static void push(std::vector<HighlightSpan> &out, int a, int b, TokenKind k){ if (b>a) out.push_back({a,b,k}); }
-static bool is_ident_start(char c){ return std::isalpha(static_cast<unsigned char>(c)) || c=='_'; }
-static bool is_ident_char(char c){ return std::isalnum(static_cast<unsigned char>(c)) || c=='_'; }
 
 GoHighlighter::GoHighlighter()
 {
-    const char* kw[] = {"break","case","chan","const","continue","default","defer","else","fallthrough","for","func","go","goto","if","import","interface","map","package","range","return","select","struct","switch","type","var"};
-    for (auto s: kw) kws_.insert(s);
-    const char* tp[] = {"bool","byte","complex64","complex128","error","float32","float64","int","int8","int16","int32","int64","rune","string","uint","uint8","uint16","uint32","uint64","uintptr"};
-    for (auto s: tp) types_.insert(s);
+	const char *kw[] = {
+		"break", "case", "chan", "const", "continue", "default", "defer", "else", "fallthrough", "for", "func",
+		"go", "goto", "if", "import", "interface", "map", "package", "range", "return", "select", "struct",
+		"switch", "type", "var"
+	};
+	for (auto s: kw)
+		kws_.insert(s);
+	const char *tp[] = {
+		"bool", "byte", "complex64", "complex128", "error", "float32", "float64", "int", "int8", "int16",
+		"int32", "int64", "rune", "string", "uint", "uint8", "uint16", "uint32", "uint64", "uintptr"
+	};
+	for (auto s: tp)
+		types_.insert(s);
 }
 
-void GoHighlighter::HighlightLine(const Buffer &buf, int row, std::vector<HighlightSpan> &out) const
+
+void
+GoHighlighter::HighlightLine(const Buffer &buf, int row, std::vector<HighlightSpan> &out) const
 {
-    const auto &rows = buf.Rows();
-    if (row < 0 || static_cast<std::size_t>(row) >= rows.size()) return;
-    std::string s = static_cast<std::string>(rows[static_cast<std::size_t>(row)]);
-    int n = static_cast<int>(s.size());
-    int i = 0;
-    int bol=0; while (bol<n && (s[bol]==' '||s[bol]=='\t')) ++bol;
-    // line comment
-    while (i < n) {
-        char c = s[i];
-        if (c==' '||c=='\t') { int j=i+1; while (j<n && (s[j]==' '||s[j]=='\t')) ++j; push(out,i,j,TokenKind::Whitespace); i=j; continue; }
-        if (c=='/' && i+1<n && s[i+1]=='/') { push(out,i,n,TokenKind::Comment); break; }
-        if (c=='/' && i+1<n && s[i+1]=='*') {
-            int j=i+2; bool closed=false; while (j+1<=n) { if (j+1<n && s[j]=='*' && s[j+1]=='/') { j+=2; closed=true; break; } ++j; }
-            if (!closed) { push(out,i,n,TokenKind::Comment); break; } else { push(out,i,j,TokenKind::Comment); i=j; continue; }
-        }
-        if (c=='"' || c=='`') {
-            char q=c; int j=i+1; bool esc=false; if (q=='`') { while (j<n && s[j] != '`') ++j; if (j<n) ++j; }
-            else { while (j<n){ char d=s[j++]; if (esc){esc=false; continue;} if (d=='\\'){esc=true; continue;} if (d=='"') break;} }
-            push(out,i,j,TokenKind::String); i=j; continue;
-        }
-        if (std::isdigit(static_cast<unsigned char>(c))) { int j=i+1; while (j<n && (std::isalnum(static_cast<unsigned char>(s[j]))||s[j]=='.'||s[j]=='x'||s[j]=='X'||s[j]=='_')) ++j; push(out,i,j,TokenKind::Number); i=j; continue; }
-        if (is_ident_start(c)) { int j=i+1; while (j<n && is_ident_char(s[j])) ++j; std::string id=s.substr(i,j-i); TokenKind k=TokenKind::Identifier; if (kws_.count(id)) k=TokenKind::Keyword; else if (types_.count(id)) k=TokenKind::Type; push(out,i,j,k); i=j; continue; }
-        if (std::ispunct(static_cast<unsigned char>(c))) { TokenKind k=TokenKind::Operator; if (c==';'||c==','||c=='('||c==')'||c=='{'||c=='}'||c=='['||c==']') k=TokenKind::Punctuation; push(out,i,i+1,k); ++i; continue; }
-        push(out,i,i+1,TokenKind::Default); ++i;
-    }
+	const auto &rows = buf.Rows();
+	if (row < 0 || static_cast<std::size_t>(row) >= rows.size())
+		return;
+	std::string s = static_cast<std::string>(rows[static_cast<std::size_t>(row)]);
+	int n         = static_cast<int>(s.size());
+	int i         = 0;
+	int bol       = 0;
+	while (bol < n && (s[bol] == ' ' || s[bol] == '\t'))
+		++bol;
+	// line comment
+	while (i < n) {
+		char c = s[i];
+		if (c == ' ' || c == '\t') {
+			int j = i + 1;
+			while (j < n && (s[j] == ' ' || s[j] == '\t'))
+				++j;
+			push(out, i, j, TokenKind::Whitespace);
+			i = j;
+			continue;
+		}
+		if (c == '/' && i + 1 < n && s[i + 1] == '/') {
+			push(out, i, n, TokenKind::Comment);
+			break;
+		}
+		if (c == '/' && i + 1 < n && s[i + 1] == '*') {
+			int j       = i + 2;
+			bool closed = false;
+			while (j + 1 <= n) {
+				if (j + 1 < n && s[j] == '*' && s[j + 1] == '/') {
+					j += 2;
+					closed = true;
+					break;
+				}
+				++j;
+			}
+			if (!closed) {
+				push(out, i, n, TokenKind::Comment);
+				break;
+			} else {
+				push(out, i, j, TokenKind::Comment);
+				i = j;
+				continue;
+			}
+		}
+		if (c == '"' || c == '`') {
+			char q   = c;
+			int j    = i + 1;
+			bool esc = false;
+			if (q == '`') {
+				while (j < n && s[j] != '`')
+					++j;
+				if (j < n)
+					++j;
+			} else {
+				while (j < n) {
+					char d = s[j++];
+					if (esc) {
+						esc = false;
+						continue;
+					}
+					if (d == '\\') {
+						esc = true;
+						continue;
+					}
+					if (d == '"')
+						break;
+				}
+			}
+			push(out, i, j, TokenKind::String);
+			i = j;
+			continue;
+		}
+		if (std::isdigit(static_cast<unsigned char>(c))) {
+			int j = i + 1;
+			while (j < n && (std::isalnum(static_cast<unsigned char>(s[j])) || s[j] == '.' || s[j] == 'x' ||
+			                 s[j] == 'X' || s[j] == '_'))
+				++j;
+			push(out, i, j, TokenKind::Number);
+			i = j;
+			continue;
+		}
+		if (is_ident_start(c)) {
+			int j = i + 1;
+			while (j < n && is_ident_char(s[j]))
+				++j;
+			std::string id = s.substr(i, j - i);
+			TokenKind k    = TokenKind::Identifier;
+			if (kws_.count(id))
+				k = TokenKind::Keyword;
+			else if (types_.count(id))
+				k = TokenKind::Type;
+			push(out, i, j, k);
+			i = j;
+			continue;
+		}
+		if (std::ispunct(static_cast<unsigned char>(c))) {
+			TokenKind k = TokenKind::Operator;
+			if (c == ';' || c == ',' || c == '(' || c == ')' || c == '{' || c == '}' || c == '[' || c ==
+			    ']')
+				k = TokenKind::Punctuation;
+			push(out, i, i + 1, k);
+			++i;
+			continue;
+		}
+		push(out, i, i + 1, TokenKind::Default);
+		++i;
+	}
 }
-
-} // namespace kte
+} // namespace kte
\ No newline at end of file
diff --git a/GoHighlighter.h b/GoHighlighter.h
index 89ec530..5a8bde4 100644
--- a/GoHighlighter.h
+++ b/GoHighlighter.h
@@ -5,14 +5,14 @@
 #include <unordered_set>
 
 namespace kte {
-
 class GoHighlighter final : public LanguageHighlighter {
 public:
-    GoHighlighter();
-    void HighlightLine(const Buffer &buf, int row, std::vector<HighlightSpan> &out) const override;
-private:
-    std::unordered_set<std::string> kws_;
-    std::unordered_set<std::string> types_;
-};
+	GoHighlighter();
 
-} // namespace kte
+	void HighlightLine(const Buffer &buf, int row, std::vector<HighlightSpan> &out) const override;
+
+private:
+	std::unordered_set<std::string> kws_;
+	std::unordered_set<std::string> types_;
+};
+} // namespace kte
\ No newline at end of file
diff --git a/Highlight.h b/Highlight.h
index f10961b..21537fe 100644
--- a/Highlight.h
+++ b/Highlight.h
@@ -5,35 +5,33 @@
 #include <vector>
 
 namespace kte {
-
 // Token kinds shared between renderers and highlighters
 enum class TokenKind {
-    Default,
-    Keyword,
-    Type,
-    String,
-    Char,
-    Comment,
-    Number,
-    Preproc,
-    Constant,
-    Function,
-    Operator,
-    Punctuation,
-    Identifier,
-    Whitespace,
-    Error
+	Default,
+	Keyword,
+	Type,
+	String,
+	Char,
+	Comment,
+	Number,
+	Preproc,
+	Constant,
+	Function,
+	Operator,
+	Punctuation,
+	Identifier,
+	Whitespace,
+	Error
 };
 
 struct HighlightSpan {
-    int col_start{0}; // inclusive, 0-based columns in buffer indices
-    int col_end{0};   // exclusive
-    TokenKind kind{TokenKind::Default};
+	int col_start{0}; // inclusive, 0-based columns in buffer indices
+	int col_end{0}; // exclusive
+	TokenKind kind{TokenKind::Default};
 };
 
 struct LineHighlight {
-    std::vector<HighlightSpan> spans;
-    std::uint64_t version{0}; // buffer version used for this line
+	std::vector<HighlightSpan> spans;
+	std::uint64_t version{0}; // buffer version used for this line
 };
-
-} // namespace kte
+} // namespace kte
\ No newline at end of file
diff --git a/HighlighterEngine.cc b/HighlighterEngine.cc
index abcddff..647405d 100644
--- a/HighlighterEngine.cc
+++ b/HighlighterEngine.cc
@@ -4,178 +4,206 @@
 #include <thread>
 
 namespace kte {
-
 HighlighterEngine::HighlighterEngine() = default;
+
+
 HighlighterEngine::~HighlighterEngine()
 {
-    // stop background worker
-    if (worker_running_.load()) {
-        {
-            std::lock_guard<std::mutex> lock(mtx_);
-            worker_running_.store(false);
-            has_request_ = true; // wake it up to exit
-        }
-        cv_.notify_one();
-        if (worker_.joinable()) worker_.join();
-    }
+	// stop background worker
+	if (worker_running_.load()) {
+		{
+			std::lock_guard<std::mutex> lock(mtx_);
+			worker_running_.store(false);
+			has_request_ = true; // wake it up to exit
+		}
+		cv_.notify_one();
+		if (worker_.joinable())
+			worker_.join();
+	}
 }
 
+
 void
 HighlighterEngine::SetHighlighter(std::unique_ptr<LanguageHighlighter> hl)
 {
-    std::lock_guard<std::mutex> lock(mtx_);
-    hl_ = std::move(hl);
-    cache_.clear();
-    state_cache_.clear();
-    state_last_contig_.clear();
+	std::lock_guard<std::mutex> lock(mtx_);
+	hl_ = std::move(hl);
+	cache_.clear();
+	state_cache_.clear();
+	state_last_contig_.clear();
 }
 
+
 const LineHighlight &
 HighlighterEngine::GetLine(const Buffer &buf, int row, std::uint64_t buf_version) const
 {
-    std::unique_lock<std::mutex> lock(mtx_);
-    auto it = cache_.find(row);
-    if (it != cache_.end() && it->second.version == buf_version) {
-        return it->second;
-    }
+	std::unique_lock<std::mutex> lock(mtx_);
+	auto it = cache_.find(row);
+	if (it != cache_.end() && it->second.version == buf_version) {
+		return it->second;
+	}
 
-    // Prepare destination slot to reuse its capacity and avoid allocations
-    LineHighlight &slot = cache_[row];
-    slot.version = buf_version;
-    slot.spans.clear();
+	// Prepare destination slot to reuse its capacity and avoid allocations
+	LineHighlight &slot = cache_[row];
+	slot.version        = buf_version;
+	slot.spans.clear();
 
-    if (!hl_) {
-        return slot;
-    }
+	if (!hl_) {
+		return slot;
+	}
 
-    // Copy shared_ptr-like raw pointer for use outside critical sections
-    LanguageHighlighter *hl_ptr = hl_.get();
-    bool is_stateful = dynamic_cast<StatefulHighlighter *>(hl_ptr) != nullptr;
+	// Copy shared_ptr-like raw pointer for use outside critical sections
+	LanguageHighlighter *hl_ptr = hl_.get();
+	bool is_stateful            = dynamic_cast<StatefulHighlighter *>(hl_ptr) != nullptr;
 
-    if (!is_stateful) {
-        // Stateless fast path: we can release the lock while computing to reduce contention
-        auto &out = slot.spans;
-        lock.unlock();
-        hl_ptr->HighlightLine(buf, row, out);
-        return cache_.at(row);
-    }
+	if (!is_stateful) {
+		// Stateless fast path: we can release the lock while computing to reduce contention
+		auto &out = slot.spans;
+		lock.unlock();
+		hl_ptr->HighlightLine(buf, row, out);
+		return cache_.at(row);
+	}
 
-    // Stateful path: we need to walk from a known previous state. Keep lock while consulting caches,
-    // but release during heavy computation.
-    auto *stateful = static_cast<StatefulHighlighter *>(hl_ptr);
+	// Stateful path: we need to walk from a known previous state. Keep lock while consulting caches,
+	// but release during heavy computation.
+	auto *stateful = static_cast<StatefulHighlighter *>(hl_ptr);
 
-    StatefulHighlighter::LineState prev_state;
-    int start_row = -1;
-    if (!state_cache_.empty()) {
-        // linear search over map (unordered), track best candidate
-        int best = -1;
-        for (const auto &kv : state_cache_) {
-            int r = kv.first;
-            if (r <= row - 1 && kv.second.version == buf_version) {
-                if (r > best) best = r;
-            }
-        }
-        if (best >= 0) {
-            start_row = best;
-            prev_state = state_cache_.at(best).state;
-        }
-    }
+	StatefulHighlighter::LineState prev_state;
+	int start_row = -1;
+	if (!state_cache_.empty()) {
+		// linear search over map (unordered), track best candidate
+		int best = -1;
+		for (const auto &kv: state_cache_) {
+			int r = kv.first;
+			if (r <= row - 1 && kv.second.version == buf_version) {
+				if (r > best)
+					best = r;
+			}
+		}
+		if (best >= 0) {
+			start_row  = best;
+			prev_state = state_cache_.at(best).state;
+		}
+	}
 
-    // We'll compute states and the target line's spans without holding the lock for most of the work.
-    // Create a local copy of prev_state and iterate rows; we will update caches under lock.
-    lock.unlock();
-    StatefulHighlighter::LineState cur_state = prev_state;
-    for (int r = start_row + 1; r <= row; ++r) {
-        std::vector<HighlightSpan> tmp;
-        std::vector<HighlightSpan> &out = (r == row) ? slot.spans : tmp;
-        auto next_state = stateful->HighlightLineStateful(buf, r, cur_state, out);
-        // Update state cache for r
-        std::lock_guard<std::mutex> gl(mtx_);
-        StateEntry se;
-        se.version = buf_version;
-        se.state = next_state;
-        state_cache_[r] = se;
-        cur_state = next_state;
-    }
+	// We'll compute states and the target line's spans without holding the lock for most of the work.
+	// Create a local copy of prev_state and iterate rows; we will update caches under lock.
+	lock.unlock();
+	StatefulHighlighter::LineState cur_state = prev_state;
+	for (int r = start_row + 1; r <= row; ++r) {
+		std::vector<HighlightSpan> tmp;
+		std::vector<HighlightSpan> &out = (r == row) ? slot.spans : tmp;
+		auto next_state                 = stateful->HighlightLineStateful(buf, r, cur_state, out);
+		// Update state cache for r
+		std::lock_guard<std::mutex> gl(mtx_);
+		StateEntry se;
+		se.version      = buf_version;
+		se.state        = next_state;
+		state_cache_[r] = se;
+		cur_state       = next_state;
+	}
 
-    // Return reference under lock to ensure slot's address stability in map
-    lock.lock();
-    return cache_.at(row);
+	// Return reference under lock to ensure slot's address stability in map
+	lock.lock();
+	return cache_.at(row);
 }
 
+
 void
 HighlighterEngine::InvalidateFrom(int row)
 {
-    std::lock_guard<std::mutex> lock(mtx_);
-    if (cache_.empty()) return;
-    // Simple implementation: erase all rows >= row
-    for (auto it = cache_.begin(); it != cache_.end(); ) {
-        if (it->first >= row) it = cache_.erase(it); else ++it;
-    }
-    if (!state_cache_.empty()) {
-        for (auto it = state_cache_.begin(); it != state_cache_.end(); ) {
-            if (it->first >= row) it = state_cache_.erase(it); else ++it;
-        }
-    }
+	std::lock_guard<std::mutex> lock(mtx_);
+	if (cache_.empty())
+		return;
+	// Simple implementation: erase all rows >= row
+	for (auto it = cache_.begin(); it != cache_.end();) {
+		if (it->first >= row)
+			it = cache_.erase(it);
+		else
+			++it;
+	}
+	if (!state_cache_.empty()) {
+		for (auto it = state_cache_.begin(); it != state_cache_.end();) {
+			if (it->first >= row)
+				it = state_cache_.erase(it);
+			else
+				++it;
+		}
+	}
 }
 
-void HighlighterEngine::ensure_worker_started() const
+
+void
+HighlighterEngine::ensure_worker_started() const
 {
-    if (worker_running_.load()) return;
-    worker_running_.store(true);
-    worker_ = std::thread([this]() { this->worker_loop(); });
+	if (worker_running_.load())
+		return;
+	worker_running_.store(true);
+	worker_ = std::thread([this]() {
+		this->worker_loop();
+	});
 }
 
-void HighlighterEngine::worker_loop() const
+
+void
+HighlighterEngine::worker_loop() const
 {
-    std::unique_lock<std::mutex> lock(mtx_);
-    while (worker_running_.load()) {
-        cv_.wait(lock, [this]() { return has_request_ || !worker_running_.load(); });
-        if (!worker_running_.load()) break;
-        WarmRequest req = pending_;
-        has_request_ = false;
-        // Copy locals then release lock while computing
-        lock.unlock();
-        if (req.buf) {
-            int start = std::max(0, req.start_row);
-            int end = std::max(start, req.end_row);
-            for (int r = start; r <= end; ++r) {
-                // Re-check version staleness quickly by peeking cache version; not strictly necessary
-                // Compute line; GetLine is thread-safe
-                (void)this->GetLine(*req.buf, r, req.version);
-            }
-        }
-        lock.lock();
-    }
+	std::unique_lock<std::mutex> lock(mtx_);
+	while (worker_running_.load()) {
+		cv_.wait(lock, [this]() {
+			return has_request_ || !worker_running_.load();
+		});
+		if (!worker_running_.load())
+			break;
+		WarmRequest req = pending_;
+		has_request_    = false;
+		// Copy locals then release lock while computing
+		lock.unlock();
+		if (req.buf) {
+			int start = std::max(0, req.start_row);
+			int end   = std::max(start, req.end_row);
+			for (int r = start; r <= end; ++r) {
+				// Re-check version staleness quickly by peeking cache version; not strictly necessary
+				// Compute line; GetLine is thread-safe
+				(void) this->GetLine(*req.buf, r, req.version);
+			}
+		}
+		lock.lock();
+	}
 }
 
-void HighlighterEngine::PrefetchViewport(const Buffer &buf, int first_row, int row_count, std::uint64_t buf_version, int warm_margin) const
+
+void
+HighlighterEngine::PrefetchViewport(const Buffer &buf, int first_row, int row_count, std::uint64_t buf_version,
+                                    int warm_margin) const
 {
-    if (row_count <= 0) return;
-    // Synchronously compute visible rows to ensure cache hits during draw
-    int start = std::max(0, first_row);
-    int end = start + row_count - 1;
-    int max_rows = static_cast<int>(buf.Nrows());
-    if (start >= max_rows) return;
-    if (end >= max_rows) end = max_rows - 1;
+	if (row_count <= 0)
+		return;
+	// Synchronously compute visible rows to ensure cache hits during draw
+	int start    = std::max(0, first_row);
+	int end      = start + row_count - 1;
+	int max_rows = static_cast<int>(buf.Nrows());
+	if (start >= max_rows)
+		return;
+	if (end >= max_rows)
+		end = max_rows - 1;
 
-    for (int r = start; r <= end; ++r) {
-        (void)GetLine(buf, r, buf_version);
-    }
+	for (int r = start; r <= end; ++r) {
+		(void) GetLine(buf, r, buf_version);
+	}
 
-    // Enqueue background warm-around
-    int warm_start = std::max(0, start - warm_margin);
-    int warm_end = std::min(max_rows - 1, end + warm_margin);
-    {
-        std::lock_guard<std::mutex> lock(mtx_);
-        pending_.buf = &buf;
-        pending_.version = buf_version;
-        pending_.start_row = warm_start;
-        pending_.end_row = warm_end;
-        has_request_ = true;
-    }
-    ensure_worker_started();
-    cv_.notify_one();
+	// Enqueue background warm-around
+	int warm_start = std::max(0, start - warm_margin);
+	int warm_end   = std::min(max_rows - 1, end + warm_margin);
+	{
+		std::lock_guard<std::mutex> lock(mtx_);
+		pending_.buf       = &buf;
+		pending_.version   = buf_version;
+		pending_.start_row = warm_start;
+		pending_.end_row   = warm_end;
+		has_request_       = true;
+	}
+	ensure_worker_started();
+	cv_.notify_one();
 }
-
-} // namespace kte
+} // namespace kte
\ No newline at end of file
diff --git a/HighlighterEngine.h b/HighlighterEngine.h
index a57af91..b95569d 100644
--- a/HighlighterEngine.h
+++ b/HighlighterEngine.h
@@ -16,61 +16,70 @@
 class Buffer;
 
 namespace kte {
-
 class HighlighterEngine {
 public:
-    HighlighterEngine();
-    ~HighlighterEngine();
+	HighlighterEngine();
 
-    void SetHighlighter(std::unique_ptr<LanguageHighlighter> hl);
+	~HighlighterEngine();
 
-    // Retrieve highlights for a given line and buffer version.
-    // If cache is stale, recompute using the current highlighter.
-    const LineHighlight &GetLine(const Buffer &buf, int row, std::uint64_t buf_version) const;
+	void SetHighlighter(std::unique_ptr<LanguageHighlighter> hl);
 
-    // Invalidate cached lines from row (inclusive)
-    void InvalidateFrom(int row);
+	// Retrieve highlights for a given line and buffer version.
+	// If cache is stale, recompute using the current highlighter.
+	const LineHighlight &GetLine(const Buffer &buf, int row, std::uint64_t buf_version) const;
 
-    bool HasHighlighter() const { return static_cast<bool>(hl_); }
+	// Invalidate cached lines from row (inclusive)
+	void InvalidateFrom(int row);
 
-    // Phase 3: viewport-first prefetch and background warming
-    // Compute only the visible range now, and enqueue a background warm-around task.
-    // warm_margin: how many extra lines above/below to warm in the background.
-    void PrefetchViewport(const Buffer &buf, int first_row, int row_count, std::uint64_t buf_version, int warm_margin = 200) const;
+
+	bool HasHighlighter() const
+	{
+		return static_cast<bool>(hl_);
+	}
+
+
+	// Phase 3: viewport-first prefetch and background warming
+	// Compute only the visible range now, and enqueue a background warm-around task.
+	// warm_margin: how many extra lines above/below to warm in the background.
+	void PrefetchViewport(const Buffer &buf, int first_row, int row_count, std::uint64_t buf_version,
+	                      int warm_margin = 200) const;
 
 private:
-    std::unique_ptr<LanguageHighlighter> hl_;
-    // Simple cache by row index (mutable to allow caching in const GetLine)
-    mutable std::unordered_map<int, LineHighlight> cache_;
-    // For stateful highlighters, remember per-line state (state after finishing that row)
-    struct StateEntry {
-        std::uint64_t version{0};
-        // Using the interface type; forward-declare via header
-        StatefulHighlighter::LineState state;
-    };
-    mutable std::unordered_map<int, StateEntry> state_cache_;
+	std::unique_ptr<LanguageHighlighter> hl_;
+	// Simple cache by row index (mutable to allow caching in const GetLine)
+	mutable std::unordered_map<int, LineHighlight> cache_;
 
-    // Track best known contiguous state row for a given version to avoid O(n) scans
-    mutable std::unordered_map<std::uint64_t, int> state_last_contig_;
+	// For stateful highlighters, remember per-line state (state after finishing that row)
+	struct StateEntry {
+		std::uint64_t version{0};
+		// Using the interface type; forward-declare via header
+		StatefulHighlighter::LineState state;
+	};
 
-    // Thread-safety for caches and background worker state
-    mutable std::mutex mtx_;
+	mutable std::unordered_map<int, StateEntry> state_cache_;
 
-    // Background warmer
-    struct WarmRequest {
-        const Buffer *buf{nullptr};
-        std::uint64_t version{0};
-        int start_row{0};
-        int end_row{0}; // inclusive
-    };
-    mutable std::condition_variable cv_;
-    mutable std::thread worker_;
-    mutable std::atomic<bool> worker_running_{false};
-    mutable bool has_request_{false};
-    mutable WarmRequest pending_{};
+	// Track best known contiguous state row for a given version to avoid O(n) scans
+	mutable std::unordered_map<std::uint64_t, int> state_last_contig_;
 
-    void ensure_worker_started() const;
-    void worker_loop() const;
+	// Thread-safety for caches and background worker state
+	mutable std::mutex mtx_;
+
+	// Background warmer
+	struct WarmRequest {
+		const Buffer *buf{nullptr};
+		std::uint64_t version{0};
+		int start_row{0};
+		int end_row{0}; // inclusive
+	};
+
+	mutable std::condition_variable cv_;
+	mutable std::thread worker_;
+	mutable std::atomic<bool> worker_running_{false};
+	mutable bool has_request_{false};
+	mutable WarmRequest pending_{};
+
+	void ensure_worker_started() const;
+
+	void worker_loop() const;
 };
-
-} // namespace kte
+} // namespace kte
\ No newline at end of file
diff --git a/HighlighterRegistry.cc b/HighlighterRegistry.cc
index b2c67a8..50bea1c 100644
--- a/HighlighterRegistry.cc
+++ b/HighlighterRegistry.cc
@@ -8,19 +8,28 @@
 
 // Forward declare simple highlighters implemented in this project
 namespace kte {
-
 // Registration storage
 struct RegEntry {
-    std::string ft; // normalized
-    HighlighterRegistry::Factory factory;
+	std::string ft; // normalized
+	HighlighterRegistry::Factory factory;
 };
 
-static std::vector<RegEntry> &registry() {
-    static std::vector<RegEntry> reg;
-    return reg;
+
+static std::vector<RegEntry> &
+registry()
+{
+	static std::vector<RegEntry> reg;
+	return reg;
 }
-class JSONHighlighter; class MarkdownHighlighter; class ShellHighlighter;
-class GoHighlighter; class PythonHighlighter; class RustHighlighter; class LispHighlighter;
+
+
+class JSONHighlighter;
+class MarkdownHighlighter;
+class ShellHighlighter;
+class GoHighlighter;
+class PythonHighlighter;
+class RustHighlighter;
+class LispHighlighter;
 }
 
 // Headers for the above
@@ -33,125 +42,182 @@ class GoHighlighter; class PythonHighlighter; class RustHighlighter; class LispH
 #include "LispHighlighter.h"
 
 namespace kte {
-
-static std::string to_lower(std::string_view s) {
-    std::string r(s);
-    std::transform(r.begin(), r.end(), r.begin(), [](unsigned char c){ return static_cast<char>(std::tolower(c)); });
-    return r;
-}
-
-std::string HighlighterRegistry::Normalize(std::string_view ft)
+static std::string
+to_lower(std::string_view s)
 {
-    std::string f = to_lower(ft);
-    if (f == "c" || f == "c++" || f == "cc" || f == "hpp" || f == "hh" || f == "h" || f == "cxx") return "cpp";
-    if (f == "cpp") return "cpp";
-    if (f == "json") return "json";
-    if (f == "markdown" || f == "md" || f == "mkd" || f == "mdown") return "markdown";
-    if (f == "shell" || f == "sh" || f == "bash" || f == "zsh" || f == "ksh" || f == "fish") return "shell";
-    if (f == "go" || f == "golang") return "go";
-    if (f == "py" || f == "python") return "python";
-    if (f == "rs" || f == "rust") return "rust";
-    if (f == "lisp" || f == "scheme" || f == "scm" || f == "rkt" || f == "el" || f == "clj" || f == "cljc" || f == "cl") return "lisp";
-    return f;
+	std::string r(s);
+	std::transform(r.begin(), r.end(), r.begin(), [](unsigned char c) {
+		return static_cast<char>(std::tolower(c));
+	});
+	return r;
 }
 
-std::unique_ptr<LanguageHighlighter> HighlighterRegistry::CreateFor(std::string_view filetype)
+
+std::string
+HighlighterRegistry::Normalize(std::string_view ft)
 {
-    std::string ft = Normalize(filetype);
-    // Prefer externally registered factories
-    for (const auto &e : registry()) {
-        if (e.ft == ft && e.factory) return e.factory();
-    }
-    if (ft == "cpp") return std::make_unique<CppHighlighter>();
-    if (ft == "json") return std::make_unique<JSONHighlighter>();
-    if (ft == "markdown") return std::make_unique<MarkdownHighlighter>();
-    if (ft == "shell") return std::make_unique<ShellHighlighter>();
-    if (ft == "go") return std::make_unique<GoHighlighter>();
-    if (ft == "python") return std::make_unique<PythonHighlighter>();
-    if (ft == "rust") return std::make_unique<RustHighlighter>();
-    if (ft == "lisp") return std::make_unique<LispHighlighter>();
-    return nullptr;
+	std::string f = to_lower(ft);
+	if (f == "c" || f == "c++" || f == "cc" || f == "hpp" || f == "hh" || f == "h" || f == "cxx")
+		return "cpp";
+	if (f == "cpp")
+		return "cpp";
+	if (f == "json")
+		return "json";
+	if (f == "markdown" || f == "md" || f == "mkd" || f == "mdown")
+		return "markdown";
+	if (f == "shell" || f == "sh" || f == "bash" || f == "zsh" || f == "ksh" || f == "fish")
+		return "shell";
+	if (f == "go" || f == "golang")
+		return "go";
+	if (f == "py" || f == "python")
+		return "python";
+	if (f == "rs" || f == "rust")
+		return "rust";
+	if (f == "lisp" || f == "scheme" || f == "scm" || f == "rkt" || f == "el" || f == "clj" || f == "cljc" || f ==
+	    "cl")
+		return "lisp";
+	return f;
 }
 
-static std::string shebang_to_ft(std::string_view first_line) {
-    if (first_line.size() < 2 || first_line.substr(0,2) != "#!") return "";
-    std::string low = to_lower(first_line);
-    if (low.find("python") != std::string::npos) return "python";
-    if (low.find("bash") != std::string::npos) return "shell";
-    if (low.find("sh") != std::string::npos) return "shell";
-    if (low.find("zsh") != std::string::npos) return "shell";
-    if (low.find("fish") != std::string::npos) return "shell";
-    if (low.find("scheme") != std::string::npos || low.find("racket") != std::string::npos || low.find("guile") != std::string::npos) return "lisp";
-    return "";
-}
 
-std::string HighlighterRegistry::DetectForPath(std::string_view path, std::string_view first_line)
+std::unique_ptr<LanguageHighlighter>
+HighlighterRegistry::CreateFor(std::string_view filetype)
 {
-    // Extension
-    std::string p(path);
-    std::error_code ec;
-    std::string ext = std::filesystem::path(p).extension().string();
-    for (auto &ch: ext) ch = static_cast<char>(std::tolower(static_cast<unsigned char>(ch)));
-    if (!ext.empty()) {
-        if (ext == ".c" || ext == ".cc" || ext == ".cpp" || ext == ".cxx" || ext == ".h" || ext == ".hpp" || ext == ".hh") return "cpp";
-        if (ext == ".json") return "json";
-        if (ext == ".md" || ext == ".markdown" || ext == ".mkd") return "markdown";
-        if (ext == ".sh" || ext == ".bash" || ext == ".zsh" || ext == ".ksh" || ext == ".fish") return "shell";
-        if (ext == ".go") return "go";
-        if (ext == ".py") return "python";
-        if (ext == ".rs") return "rust";
-        if (ext == ".lisp" || ext == ".scm" || ext == ".rkt" || ext == ".el" || ext == ".clj" || ext == ".cljc" || ext == ".cl") return "lisp";
-    }
-    // Shebang
-    std::string ft = shebang_to_ft(first_line);
-    return ft;
+	std::string ft = Normalize(filetype);
+	// Prefer externally registered factories
+	for (const auto &e: registry()) {
+		if (e.ft == ft && e.factory)
+			return e.factory();
+	}
+	if (ft == "cpp")
+		return std::make_unique<CppHighlighter>();
+	if (ft == "json")
+		return std::make_unique<JSONHighlighter>();
+	if (ft == "markdown")
+		return std::make_unique<MarkdownHighlighter>();
+	if (ft == "shell")
+		return std::make_unique<ShellHighlighter>();
+	if (ft == "go")
+		return std::make_unique<GoHighlighter>();
+	if (ft == "python")
+		return std::make_unique<PythonHighlighter>();
+	if (ft == "rust")
+		return std::make_unique<RustHighlighter>();
+	if (ft == "lisp")
+		return std::make_unique<LispHighlighter>();
+	return nullptr;
 }
 
+
+static std::string
+shebang_to_ft(std::string_view first_line)
+{
+	if (first_line.size() < 2 || first_line.substr(0, 2) != "#!")
+		return "";
+	std::string low = to_lower(first_line);
+	if (low.find("python") != std::string::npos)
+		return "python";
+	if (low.find("bash") != std::string::npos)
+		return "shell";
+	if (low.find("sh") != std::string::npos)
+		return "shell";
+	if (low.find("zsh") != std::string::npos)
+		return "shell";
+	if (low.find("fish") != std::string::npos)
+		return "shell";
+	if (low.find("scheme") != std::string::npos || low.find("racket") != std::string::npos || low.find("guile") !=
+	    std::string::npos)
+		return "lisp";
+	return "";
+}
+
+
+std::string
+HighlighterRegistry::DetectForPath(std::string_view path, std::string_view first_line)
+{
+	// Extension
+	std::string p(path);
+	std::error_code ec;
+	std::string ext = std::filesystem::path(p).extension().string();
+	for (auto &ch: ext)
+		ch = static_cast<char>(std::tolower(static_cast<unsigned char>(ch)));
+	if (!ext.empty()) {
+		if (ext == ".c" || ext == ".cc" || ext == ".cpp" || ext == ".cxx" || ext == ".h" || ext == ".hpp" || ext
+		    == ".hh")
+			return "cpp";
+		if (ext == ".json")
+			return "json";
+		if (ext == ".md" || ext == ".markdown" || ext == ".mkd")
+			return "markdown";
+		if (ext == ".sh" || ext == ".bash" || ext == ".zsh" || ext == ".ksh" || ext == ".fish")
+			return "shell";
+		if (ext == ".go")
+			return "go";
+		if (ext == ".py")
+			return "python";
+		if (ext == ".rs")
+			return "rust";
+		if (ext == ".lisp" || ext == ".scm" || ext == ".rkt" || ext == ".el" || ext == ".clj" || ext == ".cljc"
+		    || ext == ".cl")
+			return "lisp";
+	}
+	// Shebang
+	std::string ft = shebang_to_ft(first_line);
+	return ft;
+}
 } // namespace kte
 
 // Extensibility API implementations
 namespace kte {
-
-void HighlighterRegistry::Register(std::string_view filetype, Factory factory, bool override_existing)
+void
+HighlighterRegistry::Register(std::string_view filetype, Factory factory, bool override_existing)
 {
-    std::string ft = Normalize(filetype);
-    for (auto &e : registry()) {
-        if (e.ft == ft) {
-            if (override_existing) e.factory = std::move(factory);
-            return;
-        }
-    }
-    registry().push_back(RegEntry{ft, std::move(factory)});
+	std::string ft = Normalize(filetype);
+	for (auto &e: registry()) {
+		if (e.ft == ft) {
+			if (override_existing)
+				e.factory = std::move(factory);
+			return;
+		}
+	}
+	registry().push_back(RegEntry{ft, std::move(factory)});
 }
 
-bool HighlighterRegistry::IsRegistered(std::string_view filetype)
+
+bool
+HighlighterRegistry::IsRegistered(std::string_view filetype)
 {
-    std::string ft = Normalize(filetype);
-    for (const auto &e : registry()) if (e.ft == ft) return true;
-    return false;
+	std::string ft = Normalize(filetype);
+	for (const auto &e: registry())
+		if (e.ft == ft)
+			return true;
+	return false;
 }
 
-std::vector<std::string> HighlighterRegistry::RegisteredFiletypes()
+
+std::vector<std::string>
+HighlighterRegistry::RegisteredFiletypes()
 {
-    std::vector<std::string> out;
-    out.reserve(registry().size());
-    for (const auto &e : registry()) out.push_back(e.ft);
-    return out;
+	std::vector<std::string> out;
+	out.reserve(registry().size());
+	for (const auto &e: registry())
+		out.push_back(e.ft);
+	return out;
 }
 
 #ifdef KTE_ENABLE_TREESITTER
 // Forward declare adapter factory
-std::unique_ptr<LanguageHighlighter> CreateTreeSitterHighlighter(const char* filetype,
-                                                                 const void* (*get_lang)());
+std::unique_ptr<LanguageHighlighter> CreateTreeSitterHighlighter(const char *filetype,
+                                                                 const void * (*get_lang)());
 
-void HighlighterRegistry::RegisterTreeSitter(std::string_view filetype,
-                                             const TSLanguage* (*get_language)())
+void
+HighlighterRegistry::RegisterTreeSitter(std::string_view filetype,
+                                        const TSLanguage * (*get_language)())
 {
-    std::string ft = Normalize(filetype);
-    Register(ft, [ft, get_language]() {
-        return CreateTreeSitterHighlighter(ft.c_str(), reinterpret_cast<const void* (*)()>(get_language));
-    }, /*override_existing=*/true);
+	std::string ft = Normalize(filetype);
+	Register(ft, [ft, get_language]() {
+		return CreateTreeSitterHighlighter(ft.c_str(), reinterpret_cast<const void* (*)()>(get_language));
+	}, /*override_existing=*/true);
 }
 #endif
-
-} // namespace kte
+} // namespace kte
\ No newline at end of file
diff --git a/HighlighterRegistry.h b/HighlighterRegistry.h
index 5eb39f7..f44e5c3 100644
--- a/HighlighterRegistry.h
+++ b/HighlighterRegistry.h
@@ -10,40 +10,38 @@
 #include "LanguageHighlighter.h"
 
 namespace kte {
-
 class HighlighterRegistry {
 public:
-    using Factory = std::function<std::unique_ptr<LanguageHighlighter>()>;
+	using Factory = std::function<std::unique_ptr<LanguageHighlighter>()>;
 
-    // Create a highlighter for normalized filetype id (e.g., "cpp", "json", "markdown", "shell", "go", "python", "rust", "lisp").
-    static std::unique_ptr<LanguageHighlighter> CreateFor(std::string_view filetype);
+	// Create a highlighter for normalized filetype id (e.g., "cpp", "json", "markdown", "shell", "go", "python", "rust", "lisp").
+	static std::unique_ptr<LanguageHighlighter> CreateFor(std::string_view filetype);
 
-    // Detect filetype by path extension and shebang (first line).
-    // Returns normalized id or empty string if unknown.
-    static std::string DetectForPath(std::string_view path, std::string_view first_line);
+	// Detect filetype by path extension and shebang (first line).
+	// Returns normalized id or empty string if unknown.
+	static std::string DetectForPath(std::string_view path, std::string_view first_line);
 
-    // Normalize various aliases/extensions to canonical ids.
-    static std::string Normalize(std::string_view ft);
+	// Normalize various aliases/extensions to canonical ids.
+	static std::string Normalize(std::string_view ft);
 
-    // Extensibility: allow external code to register highlighters at runtime.
-    // The filetype key is normalized via Normalize(). If a factory is already registered for the
-    // normalized key and override=false, the existing factory is kept.
-    static void Register(std::string_view filetype, Factory factory, bool override_existing = true);
+	// Extensibility: allow external code to register highlighters at runtime.
+	// The filetype key is normalized via Normalize(). If a factory is already registered for the
+	// normalized key and override=false, the existing factory is kept.
+	static void Register(std::string_view filetype, Factory factory, bool override_existing = true);
 
-    // Returns true if a factory is registered for the (normalized) filetype.
-    static bool IsRegistered(std::string_view filetype);
+	// Returns true if a factory is registered for the (normalized) filetype.
+	static bool IsRegistered(std::string_view filetype);
 
-    // Return a list of currently registered (normalized) filetypes. Primarily for diagnostics/tests.
-    static std::vector<std::string> RegisteredFiletypes();
+	// Return a list of currently registered (normalized) filetypes. Primarily for diagnostics/tests.
+	static std::vector<std::string> RegisteredFiletypes();
 
 #ifdef KTE_ENABLE_TREESITTER
-    // Forward declaration to avoid hard dependency when disabled.
-    struct TSLanguage;
-    // Convenience: register a Tree-sitter-backed highlighter for a filetype.
-    // The getter should return a non-null language pointer for the grammar.
-    static void RegisterTreeSitter(std::string_view filetype,
-                                   const TSLanguage* (*get_language)());
+	// Forward declaration to avoid hard dependency when disabled.
+	struct TSLanguage;
+	// Convenience: register a Tree-sitter-backed highlighter for a filetype.
+	// The getter should return a non-null language pointer for the grammar.
+	static void RegisterTreeSitter(std::string_view filetype,
+	                               const TSLanguage * (*get_language)());
 #endif
 };
-
-} // namespace kte
+} // namespace kte
\ No newline at end of file
diff --git a/JsonHighlighter.cc b/JsonHighlighter.cc
index 693d3ff..140f458 100644
--- a/JsonHighlighter.cc
+++ b/JsonHighlighter.cc
@@ -3,40 +3,88 @@
 #include <cctype>
 
 namespace kte {
-
-static bool is_digit(char c) { return c >= '0' && c <= '9'; }
-
-void JSONHighlighter::HighlightLine(const Buffer &buf, int row, std::vector<HighlightSpan> &out) const
+static bool
+is_digit(char c)
 {
-    const auto &rows = buf.Rows();
-    if (row < 0 || static_cast<std::size_t>(row) >= rows.size()) return;
-    std::string s = static_cast<std::string>(rows[static_cast<std::size_t>(row)]);
-    int n = static_cast<int>(s.size());
-    auto push = [&](int a, int b, TokenKind k){ if (b> a) out.push_back({a,b,k}); };
-
-    int i = 0;
-    while (i < n) {
-        char c = s[i];
-        if (c == ' ' || c == '\t') { int j=i+1; while (j<n && (s[j]==' '||s[j]=='\t')) ++j; push(i,j,TokenKind::Whitespace); i=j; continue; }
-        if (c == '"') {
-            int j = i+1; bool esc=false; while (j < n) { char d = s[j++]; if (esc) { esc=false; continue; } if (d == '\\') { esc=true; continue; } if (d == '"') break; }
-            push(i, j, TokenKind::String); i = j; continue;
-        }
-        if (is_digit(c) || (c=='-' && i+1<n && is_digit(s[i+1]))) {
-            int j=i+1; while (j<n && (std::isdigit(static_cast<unsigned char>(s[j]))||s[j]=='.'||s[j]=='e'||s[j]=='E'||s[j]=='+'||s[j]=='-'||s[j]=='_')) ++j; push(i,j,TokenKind::Number); i=j; continue;
-        }
-        // booleans/null
-        if (std::isalpha(static_cast<unsigned char>(c))) {
-            int j=i+1; while (j<n && std::isalpha(static_cast<unsigned char>(s[j]))) ++j;
-            std::string id = s.substr(i, j-i);
-            if (id == "true" || id == "false" || id == "null") push(i,j,TokenKind::Constant); else push(i,j,TokenKind::Identifier);
-            i=j; continue;
-        }
-        // punctuation
-        if (c=='{'||c=='}'||c=='['||c==']'||c==','||c==':' ) { push(i,i+1,TokenKind::Punctuation); ++i; continue; }
-        // fallback
-        push(i,i+1,TokenKind::Default); ++i;
-    }
+	return c >= '0' && c <= '9';
 }
 
-} // namespace kte
+
+void
+JSONHighlighter::HighlightLine(const Buffer &buf, int row, std::vector<HighlightSpan> &out) const
+{
+	const auto &rows = buf.Rows();
+	if (row < 0 || static_cast<std::size_t>(row) >= rows.size())
+		return;
+	std::string s = static_cast<std::string>(rows[static_cast<std::size_t>(row)]);
+	int n         = static_cast<int>(s.size());
+	auto push     = [&](int a, int b, TokenKind k) {
+		if (b > a)
+			out.push_back({a, b, k});
+	};
+
+	int i = 0;
+	while (i < n) {
+		char c = s[i];
+		if (c == ' ' || c == '\t') {
+			int j = i + 1;
+			while (j < n && (s[j] == ' ' || s[j] == '\t'))
+				++j;
+			push(i, j, TokenKind::Whitespace);
+			i = j;
+			continue;
+		}
+		if (c == '"') {
+			int j    = i + 1;
+			bool esc = false;
+			while (j < n) {
+				char d = s[j++];
+				if (esc) {
+					esc = false;
+					continue;
+				}
+				if (d == '\\') {
+					esc = true;
+					continue;
+				}
+				if (d == '"')
+					break;
+			}
+			push(i, j, TokenKind::String);
+			i = j;
+			continue;
+		}
+		if (is_digit(c) || (c == '-' && i + 1 < n && is_digit(s[i + 1]))) {
+			int j = i + 1;
+			while (j < n && (std::isdigit(static_cast<unsigned char>(s[j])) || s[j] == '.' || s[j] == 'e' ||
+			                 s[j] == 'E' || s[j] == '+' || s[j] == '-' || s[j] == '_'))
+				++j;
+			push(i, j, TokenKind::Number);
+			i = j;
+			continue;
+		}
+		// booleans/null
+		if (std::isalpha(static_cast<unsigned char>(c))) {
+			int j = i + 1;
+			while (j < n && std::isalpha(static_cast<unsigned char>(s[j])))
+				++j;
+			std::string id = s.substr(i, j - i);
+			if (id == "true" || id == "false" || id == "null")
+				push(i, j, TokenKind::Constant);
+			else
+				push(i, j, TokenKind::Identifier);
+			i = j;
+			continue;
+		}
+		// punctuation
+		if (c == '{' || c == '}' || c == '[' || c == ']' || c == ',' || c == ':') {
+			push(i, i + 1, TokenKind::Punctuation);
+			++i;
+			continue;
+		}
+		// fallback
+		push(i, i + 1, TokenKind::Default);
+		++i;
+	}
+}
+} // namespace kte
\ No newline at end of file
diff --git a/JsonHighlighter.h b/JsonHighlighter.h
index 314619f..0273d4f 100644
--- a/JsonHighlighter.h
+++ b/JsonHighlighter.h
@@ -5,10 +5,8 @@
 #include <vector>
 
 namespace kte {
-
 class JSONHighlighter final : public LanguageHighlighter {
 public:
-    void HighlightLine(const Buffer &buf, int row, std::vector<HighlightSpan> &out) const override;
+	void HighlightLine(const Buffer &buf, int row, std::vector<HighlightSpan> &out) const override;
 };
-
-} // namespace kte
+} // namespace kte
\ No newline at end of file
diff --git a/LanguageHighlighter.h b/LanguageHighlighter.h
index cdd0d45..a73eb85 100644
--- a/LanguageHighlighter.h
+++ b/LanguageHighlighter.h
@@ -10,34 +10,42 @@
 class Buffer;
 
 namespace kte {
-
 class LanguageHighlighter {
 public:
-    virtual ~LanguageHighlighter() = default;
-    // Produce highlight spans for a given buffer row. Implementations should append to out.
-    virtual void HighlightLine(const Buffer &buf, int row, std::vector<HighlightSpan> &out) const = 0;
-    virtual bool Stateful() const { return false; }
+	virtual ~LanguageHighlighter() = default;
+
+	// Produce highlight spans for a given buffer row. Implementations should append to out.
+	virtual void HighlightLine(const Buffer &buf, int row, std::vector<HighlightSpan> &out) const = 0;
+
+
+	virtual bool Stateful() const
+	{
+		return false;
+	}
 };
 
 // Optional extension for stateful highlighters (e.g., multi-line comments/strings).
 // Engines may detect and use this via dynamic_cast without breaking stateless impls.
 class StatefulHighlighter : public LanguageHighlighter {
 public:
-    struct LineState {
-        bool in_block_comment{false};
-        bool in_raw_string{false};
-        // For raw strings, remember the delimiter between the opening R"delim( and closing )delim"
-        std::string raw_delim;
-    };
+	struct LineState {
+		bool in_block_comment{false};
+		bool in_raw_string{false};
+		// For raw strings, remember the delimiter between the opening R"delim( and closing )delim"
+		std::string raw_delim;
+	};
 
-    // Highlight one line given the previous line state; return the resulting state after this line.
-    // Implementations should append spans for this line to out and compute the next state.
-    virtual LineState HighlightLineStateful(const Buffer &buf,
-                                            int row,
-                                            const LineState &prev,
-                                            std::vector<HighlightSpan> &out) const = 0;
+	// Highlight one line given the previous line state; return the resulting state after this line.
+	// Implementations should append spans for this line to out and compute the next state.
+	virtual LineState HighlightLineStateful(const Buffer &buf,
+	                                        int row,
+	                                        const LineState &prev,
+	                                        std::vector<HighlightSpan> &out) const = 0;
 
-    bool Stateful() const override { return true; }
+
+	bool Stateful() const override
+	{
+		return true;
+	}
 };
-
-} // namespace kte
+} // namespace kte
\ No newline at end of file
diff --git a/LispHighlighter.cc b/LispHighlighter.cc
index e8b0763..f128ec7 100644
--- a/LispHighlighter.cc
+++ b/LispHighlighter.cc
@@ -3,39 +3,105 @@
 #include <cctype>
 
 namespace kte {
+static void
+push(std::vector<HighlightSpan> &out, int a, int b, TokenKind k)
+{
+	if (b > a)
+		out.push_back({a, b, k});
+}
 
-static void push(std::vector<HighlightSpan> &out, int a, int b, TokenKind k){ if (b>a) out.push_back({a,b,k}); }
 
 LispHighlighter::LispHighlighter()
 {
-    const char* kw[] = {"defun","lambda","let","let*","define","set!","if","cond","begin","quote","quasiquote","unquote","unquote-splicing","loop","do","and","or","not"};
-    for (auto s: kw) kws_.insert(s);
+	const char *kw[] = {
+		"defun", "lambda", "let", "let*", "define", "set!", "if", "cond", "begin", "quote", "quasiquote",
+		"unquote", "unquote-splicing", "loop", "do", "and", "or", "not"
+	};
+	for (auto s: kw)
+		kws_.insert(s);
 }
 
-void LispHighlighter::HighlightLine(const Buffer &buf, int row, std::vector<HighlightSpan> &out) const
+
+void
+LispHighlighter::HighlightLine(const Buffer &buf, int row, std::vector<HighlightSpan> &out) const
 {
-    const auto &rows = buf.Rows();
-    if (row < 0 || static_cast<std::size_t>(row) >= rows.size()) return;
-    std::string s = static_cast<std::string>(rows[static_cast<std::size_t>(row)]);
-    int n = static_cast<int>(s.size());
-    int i = 0;
-    int bol = 0; while (bol<n && (s[bol]==' '||s[bol]=='\t')) ++bol;
-    if (bol < n && s[bol] == ';') { push(out, bol, n, TokenKind::Comment); if (bol>0) push(out,0,bol,TokenKind::Whitespace); return; }
-    while (i < n) {
-        char c = s[i];
-        if (c==' '||c=='\t') { int j=i+1; while (j<n && (s[j]==' '||s[j]=='\t')) ++j; push(out,i,j,TokenKind::Whitespace); i=j; continue; }
-        if (c==';') { push(out,i,n,TokenKind::Comment); break; }
-        if (c=='"') { int j=i+1; bool esc=false; while (j<n){ char d=s[j++]; if (esc){esc=false; continue;} if (d=='\\'){esc=true; continue;} if (d=='"') break; } push(out,i,j,TokenKind::String); i=j; continue; }
-        if (std::isalpha(static_cast<unsigned char>(c)) || c=='*' || c=='-' || c=='+' || c=='/' || c=='_' ) {
-            int j=i+1; while (j<n && (std::isalnum(static_cast<unsigned char>(s[j])) || s[j]=='*' || s[j]=='-' || s[j]=='+' || s[j]=='/' || s[j]=='_' || s[j]=='!')) ++j;
-            std::string id=s.substr(i,j-i);
-            TokenKind k = kws_.count(id) ? TokenKind::Keyword : TokenKind::Identifier;
-            push(out,i,j,k); i=j; continue;
-        }
-        if (std::isdigit(static_cast<unsigned char>(c))) { int j=i+1; while (j<n && (std::isdigit(static_cast<unsigned char>(s[j]))||s[j]=='.')) ++j; push(out,i,j,TokenKind::Number); i=j; continue; }
-        if (std::ispunct(static_cast<unsigned char>(c))) { TokenKind k=TokenKind::Punctuation; push(out,i,i+1,k); ++i; continue; }
-        push(out,i,i+1,TokenKind::Default); ++i;
-    }
+	const auto &rows = buf.Rows();
+	if (row < 0 || static_cast<std::size_t>(row) >= rows.size())
+		return;
+	std::string s = static_cast<std::string>(rows[static_cast<std::size_t>(row)]);
+	int n         = static_cast<int>(s.size());
+	int i         = 0;
+	int bol       = 0;
+	while (bol < n && (s[bol] == ' ' || s[bol] == '\t'))
+		++bol;
+	if (bol < n && s[bol] == ';') {
+		push(out, bol, n, TokenKind::Comment);
+		if (bol > 0)
+			push(out, 0, bol, TokenKind::Whitespace);
+		return;
+	}
+	while (i < n) {
+		char c = s[i];
+		if (c == ' ' || c == '\t') {
+			int j = i + 1;
+			while (j < n && (s[j] == ' ' || s[j] == '\t'))
+				++j;
+			push(out, i, j, TokenKind::Whitespace);
+			i = j;
+			continue;
+		}
+		if (c == ';') {
+			push(out, i, n, TokenKind::Comment);
+			break;
+		}
+		if (c == '"') {
+			int j    = i + 1;
+			bool esc = false;
+			while (j < n) {
+				char d = s[j++];
+				if (esc) {
+					esc = false;
+					continue;
+				}
+				if (d == '\\') {
+					esc = true;
+					continue;
+				}
+				if (d == '"')
+					break;
+			}
+			push(out, i, j, TokenKind::String);
+			i = j;
+			continue;
+		}
+		if (std::isalpha(static_cast<unsigned char>(c)) || c == '*' || c == '-' || c == '+' || c == '/' || c ==
+		    '_') {
+			int j = i + 1;
+			while (j < n && (std::isalnum(static_cast<unsigned char>(s[j])) || s[j] == '*' || s[j] == '-' ||
+			                 s[j] == '+' || s[j] == '/' || s[j] == '_' || s[j] == '!'))
+				++j;
+			std::string id = s.substr(i, j - i);
+			TokenKind k    = kws_.count(id) ? TokenKind::Keyword : TokenKind::Identifier;
+			push(out, i, j, k);
+			i = j;
+			continue;
+		}
+		if (std::isdigit(static_cast<unsigned char>(c))) {
+			int j = i + 1;
+			while (j < n && (std::isdigit(static_cast<unsigned char>(s[j])) || s[j] == '.'))
+				++j;
+			push(out, i, j, TokenKind::Number);
+			i = j;
+			continue;
+		}
+		if (std::ispunct(static_cast<unsigned char>(c))) {
+			TokenKind k = TokenKind::Punctuation;
+			push(out, i, i + 1, k);
+			++i;
+			continue;
+		}
+		push(out, i, i + 1, TokenKind::Default);
+		++i;
+	}
 }
-
-} // namespace kte
+} // namespace kte
\ No newline at end of file
diff --git a/LispHighlighter.h b/LispHighlighter.h
index 35f6b52..0199891 100644
--- a/LispHighlighter.h
+++ b/LispHighlighter.h
@@ -5,13 +5,13 @@
 #include <unordered_set>
 
 namespace kte {
-
 class LispHighlighter final : public LanguageHighlighter {
 public:
-    LispHighlighter();
-    void HighlightLine(const Buffer &buf, int row, std::vector<HighlightSpan> &out) const override;
-private:
-    std::unordered_set<std::string> kws_;
-};
+	LispHighlighter();
 
-} // namespace kte
+	void HighlightLine(const Buffer &buf, int row, std::vector<HighlightSpan> &out) const override;
+
+private:
+	std::unordered_set<std::string> kws_;
+};
+} // namespace kte
\ No newline at end of file
diff --git a/MarkdownHighlighter.cc b/MarkdownHighlighter.cc
index 6314dfb..aff8d8b 100644
--- a/MarkdownHighlighter.cc
+++ b/MarkdownHighlighter.cc
@@ -3,86 +3,130 @@
 #include <cctype>
 
 namespace kte {
-
-static void push_span(std::vector<HighlightSpan> &out, int a, int b, TokenKind k) {
-    if (b > a) out.push_back({a,b,k});
-}
-
-void MarkdownHighlighter::HighlightLine(const Buffer &buf, int row, std::vector<HighlightSpan> &out) const
+static void
+push_span(std::vector<HighlightSpan> &out, int a, int b, TokenKind k)
 {
-    LineState st; // not used in stateless entry
-    (void)HighlightLineStateful(buf, row, st, out);
+	if (b > a)
+		out.push_back({a, b, k});
 }
 
-StatefulHighlighter::LineState MarkdownHighlighter::HighlightLineStateful(const Buffer &buf, int row, const LineState &prev, std::vector<HighlightSpan> &out) const
+
+void
+MarkdownHighlighter::HighlightLine(const Buffer &buf, int row, std::vector<HighlightSpan> &out) const
 {
-    StatefulHighlighter::LineState state = prev;
-    const auto &rows = buf.Rows();
-    if (row < 0 || static_cast<std::size_t>(row) >= rows.size()) return state;
-    std::string s = static_cast<std::string>(rows[static_cast<std::size_t>(row)]);
-    int n = static_cast<int>(s.size());
-
-    // Reuse in_block_comment flag as "in fenced code" state.
-    if (state.in_block_comment) {
-        // If line contains closing fence ``` then close after it
-        auto pos = s.find("```");
-        if (pos == std::string::npos) {
-            push_span(out, 0, n, TokenKind::String);
-            state.in_block_comment = true;
-            return state;
-        } else {
-            int end = static_cast<int>(pos + 3);
-            push_span(out, 0, end, TokenKind::String);
-            // rest of line processed normally after fence
-            int i = end;
-            // whitespace
-            if (i < n) push_span(out, i, n, TokenKind::Default);
-            state.in_block_comment = false;
-            return state;
-        }
-    }
-
-    // Detect fenced code block start at beginning (allow leading spaces)
-    int bol = 0; while (bol < n && (s[bol]==' '||s[bol]=='\t')) ++bol;
-    if (bol + 3 <= n && s.compare(bol, 3, "```") == 0) {
-        push_span(out, bol, n, TokenKind::String);
-        state.in_block_comment = true; // enter fenced mode
-        return state;
-    }
-
-    // Headings: lines starting with 1-6 '#'
-    if (bol < n && s[bol] == '#') {
-        int j = bol; while (j < n && s[j] == '#') ++j; // hashes
-        // include following space and text as Keyword to stand out
-        push_span(out, bol, n, TokenKind::Keyword);
-        return state;
-    }
-
-    // Process inline: emphasis and code spans
-    int i = 0;
-    while (i < n) {
-        char c = s[i];
-        if (c == '`') {
-            int j = i + 1; while (j < n && s[j] != '`') ++j; if (j < n) ++j;
-            push_span(out, i, j, TokenKind::String); i = j; continue;
-        }
-        if (c == '*' || c == '_') {
-            // bold/italic markers: treat the marker and until next same marker as Type to highlight
-            char m = c; int j = i + 1; while (j < n && s[j] != m) ++j; if (j < n) ++j;
-            push_span(out, i, j, TokenKind::Type); i = j; continue;
-        }
-        // links []() minimal: treat [text](url) as Function
-        if (c == '[') {
-            int j = i + 1; while (j < n && s[j] != ']') ++j; if (j < n) ++j; // include ]
-            if (j < n && s[j] == '(') { while (j < n && s[j] != ')') ++j; if (j < n) ++j; }
-            push_span(out, i, j, TokenKind::Function); i = j; continue;
-        }
-        // whitespace
-        if (c == ' ' || c == '\t') { int j=i+1; while (j<n && (s[j]==' '||s[j]=='\t')) ++j; push_span(out, i, j, TokenKind::Whitespace); i=j; continue; }
-        // fallback: default single char
-        push_span(out, i, i+1, TokenKind::Default); ++i;
-    }
-    return state;
+	LineState st; // not used in stateless entry
+	(void) HighlightLineStateful(buf, row, st, out);
 }
 
-} // namespace kte
+
+StatefulHighlighter::LineState
+MarkdownHighlighter::HighlightLineStateful(const Buffer &buf, int row, const LineState &prev,
+                                           std::vector<HighlightSpan> &out) const
+{
+	StatefulHighlighter::LineState state = prev;
+	const auto &rows                     = buf.Rows();
+	if (row < 0 || static_cast<std::size_t>(row) >= rows.size())
+		return state;
+	std::string s = static_cast<std::string>(rows[static_cast<std::size_t>(row)]);
+	int n         = static_cast<int>(s.size());
+
+	// Reuse in_block_comment flag as "in fenced code" state.
+	if (state.in_block_comment) {
+		// If line contains closing fence ``` then close after it
+		auto pos = s.find("```");
+		if (pos == std::string::npos) {
+			push_span(out, 0, n, TokenKind::String);
+			state.in_block_comment = true;
+			return state;
+		} else {
+			int end = static_cast<int>(pos + 3);
+			push_span(out, 0, end, TokenKind::String);
+			// rest of line processed normally after fence
+			int i = end;
+			// whitespace
+			if (i < n)
+				push_span(out, i, n, TokenKind::Default);
+			state.in_block_comment = false;
+			return state;
+		}
+	}
+
+	// Detect fenced code block start at beginning (allow leading spaces)
+	int bol = 0;
+	while (bol < n && (s[bol] == ' ' || s[bol] == '\t'))
+		++bol;
+	if (bol + 3 <= n && s.compare(bol, 3, "```") == 0) {
+		push_span(out, bol, n, TokenKind::String);
+		state.in_block_comment = true; // enter fenced mode
+		return state;
+	}
+
+	// Headings: lines starting with 1-6 '#'
+	if (bol < n && s[bol] == '#') {
+		int j = bol;
+		while (j < n && s[j] == '#')
+			++j; // hashes
+		// include following space and text as Keyword to stand out
+		push_span(out, bol, n, TokenKind::Keyword);
+		return state;
+	}
+
+	// Process inline: emphasis and code spans
+	int i = 0;
+	while (i < n) {
+		char c = s[i];
+		if (c == '`') {
+			int j = i + 1;
+			while (j < n && s[j] != '`')
+				++j;
+			if (j < n)
+				++j;
+			push_span(out, i, j, TokenKind::String);
+			i = j;
+			continue;
+		}
+		if (c == '*' || c == '_') {
+			// bold/italic markers: treat the marker and until next same marker as Type to highlight
+			char m = c;
+			int j  = i + 1;
+			while (j < n && s[j] != m)
+				++j;
+			if (j < n)
+				++j;
+			push_span(out, i, j, TokenKind::Type);
+			i = j;
+			continue;
+		}
+		// links []() minimal: treat [text](url) as Function
+		if (c == '[') {
+			int j = i + 1;
+			while (j < n && s[j] != ']')
+				++j;
+			if (j < n)
+				++j; // include ]
+			if (j < n && s[j] == '(') {
+				while (j < n && s[j] != ')')
+					++j;
+				if (j < n)
+					++j;
+			}
+			push_span(out, i, j, TokenKind::Function);
+			i = j;
+			continue;
+		}
+		// whitespace
+		if (c == ' ' || c == '\t') {
+			int j = i + 1;
+			while (j < n && (s[j] == ' ' || s[j] == '\t'))
+				++j;
+			push_span(out, i, j, TokenKind::Whitespace);
+			i = j;
+			continue;
+		}
+		// fallback: default single char
+		push_span(out, i, i + 1, TokenKind::Default);
+		++i;
+	}
+	return state;
+}
+} // namespace kte
\ No newline at end of file
diff --git a/MarkdownHighlighter.h b/MarkdownHighlighter.h
index 5e1c12e..aab68bf 100644
--- a/MarkdownHighlighter.h
+++ b/MarkdownHighlighter.h
@@ -4,11 +4,11 @@
 #include "LanguageHighlighter.h"
 
 namespace kte {
-
 class MarkdownHighlighter final : public StatefulHighlighter {
 public:
-    void HighlightLine(const Buffer &buf, int row, std::vector<HighlightSpan> &out) const override;
-    LineState HighlightLineStateful(const Buffer &buf, int row, const LineState &prev, std::vector<HighlightSpan> &out) const override;
-};
+	void HighlightLine(const Buffer &buf, int row, std::vector<HighlightSpan> &out) const override;
 
-} // namespace kte
+	LineState HighlightLineStateful(const Buffer &buf, int row, const LineState &prev,
+	                                std::vector<HighlightSpan> &out) const override;
+};
+} // namespace kte
\ No newline at end of file
diff --git a/NullHighlighter.cc b/NullHighlighter.cc
index 9a59036..c5cd8ef 100644
--- a/NullHighlighter.cc
+++ b/NullHighlighter.cc
@@ -2,15 +2,16 @@
 #include "Buffer.h"
 
 namespace kte {
-
-void NullHighlighter::HighlightLine(const Buffer &buf, int row, std::vector<HighlightSpan> &out) const
+void
+NullHighlighter::HighlightLine(const Buffer &buf, int row, std::vector<HighlightSpan> &out) const
 {
-    const auto &rows = buf.Rows();
-    if (row < 0 || static_cast<std::size_t>(row) >= rows.size()) return;
-    std::string s = static_cast<std::string>(rows[static_cast<std::size_t>(row)]);
-    int n = static_cast<int>(s.size());
-    if (n <= 0) return;
-    out.push_back({0, n, TokenKind::Default});
+	const auto &rows = buf.Rows();
+	if (row < 0 || static_cast<std::size_t>(row) >= rows.size())
+		return;
+	std::string s = static_cast<std::string>(rows[static_cast<std::size_t>(row)]);
+	int n         = static_cast<int>(s.size());
+	if (n <= 0)
+		return;
+	out.push_back({0, n, TokenKind::Default});
 }
-
-} // namespace kte
+} // namespace kte
\ No newline at end of file
diff --git a/NullHighlighter.h b/NullHighlighter.h
index 64e82d0..dd3d769 100644
--- a/NullHighlighter.h
+++ b/NullHighlighter.h
@@ -4,10 +4,8 @@
 #include "LanguageHighlighter.h"
 
 namespace kte {
-
 class NullHighlighter final : public LanguageHighlighter {
 public:
-    void HighlightLine(const Buffer &buf, int row, std::vector<HighlightSpan> &out) const override;
+	void HighlightLine(const Buffer &buf, int row, std::vector<HighlightSpan> &out) const override;
 };
-
-} // namespace kte
+} // namespace kte
\ No newline at end of file
diff --git a/PythonHighlighter.cc b/PythonHighlighter.cc
index ffc9235..14ea702 100644
--- a/PythonHighlighter.cc
+++ b/PythonHighlighter.cc
@@ -3,83 +3,170 @@
 #include <cctype>
 
 namespace kte {
+static void
+push(std::vector<HighlightSpan> &out, int a, int b, TokenKind k)
+{
+	if (b > a)
+		out.push_back({a, b, k});
+}
+
+
+static bool
+is_ident_start(char c)
+{
+	return std::isalpha(static_cast<unsigned char>(c)) || c == '_';
+}
+
+
+static bool
+is_ident_char(char c)
+{
+	return std::isalnum(static_cast<unsigned char>(c)) || c == '_';
+}
 
-static void push(std::vector<HighlightSpan> &out, int a, int b, TokenKind k){ if (b>a) out.push_back({a,b,k}); }
-static bool is_ident_start(char c){ return std::isalpha(static_cast<unsigned char>(c)) || c=='_'; }
-static bool is_ident_char(char c){ return std::isalnum(static_cast<unsigned char>(c)) || c=='_'; }
 
 PythonHighlighter::PythonHighlighter()
 {
-    const char* kw[] = {"and","as","assert","break","class","continue","def","del","elif","else","except","False","finally","for","from","global","if","import","in","is","lambda","None","nonlocal","not","or","pass","raise","return","True","try","while","with","yield"};
-    for (auto s: kw) kws_.insert(s);
+	const char *kw[] = {
+		"and", "as", "assert", "break", "class", "continue", "def", "del", "elif", "else", "except", "False",
+		"finally", "for", "from", "global", "if", "import", "in", "is", "lambda", "None", "nonlocal", "not",
+		"or", "pass", "raise", "return", "True", "try", "while", "with", "yield"
+	};
+	for (auto s: kw)
+		kws_.insert(s);
 }
 
-void PythonHighlighter::HighlightLine(const Buffer &buf, int row, std::vector<HighlightSpan> &out) const
+
+void
+PythonHighlighter::HighlightLine(const Buffer &buf, int row, std::vector<HighlightSpan> &out) const
 {
-    LineState st; (void)HighlightLineStateful(buf, row, st, out);
+	LineState st;
+	(void) HighlightLineStateful(buf, row, st, out);
 }
 
-StatefulHighlighter::LineState PythonHighlighter::HighlightLineStateful(const Buffer &buf, int row, const LineState &prev, std::vector<HighlightSpan> &out) const
+
+StatefulHighlighter::LineState
+PythonHighlighter::HighlightLineStateful(const Buffer &buf, int row, const LineState &prev,
+                                         std::vector<HighlightSpan> &out) const
 {
-    StatefulHighlighter::LineState state = prev;
-    const auto &rows = buf.Rows();
-    if (row < 0 || static_cast<std::size_t>(row) >= rows.size()) return state;
-    std::string s = static_cast<std::string>(rows[static_cast<std::size_t>(row)]);
-    int n = static_cast<int>(s.size());
+	StatefulHighlighter::LineState state = prev;
+	const auto &rows                     = buf.Rows();
+	if (row < 0 || static_cast<std::size_t>(row) >= rows.size())
+		return state;
+	std::string s = static_cast<std::string>(rows[static_cast<std::size_t>(row)]);
+	int n         = static_cast<int>(s.size());
 
-    // Triple-quoted string continuation uses in_raw_string with raw_delim either "'''" or "\"\"\""
-    if (state.in_raw_string && (state.raw_delim == "'''" || state.raw_delim == "\"\"\"")) {
-        auto pos = s.find(state.raw_delim);
-        if (pos == std::string::npos) {
-            push(out, 0, n, TokenKind::String);
-            return state; // still inside
-        } else {
-            int end = static_cast<int>(pos + static_cast<int>(state.raw_delim.size()));
-            push(out, 0, end, TokenKind::String);
-            // remainder processed normally
-            s = s.substr(end);
-            n = static_cast<int>(s.size());
-            state.in_raw_string = false; state.raw_delim.clear();
-            // Continue parsing remainder as a separate small loop
-            int base = end; // original offset, but we already emitted to 'out' with base=0; following spans should be from 'end'
-            // For simplicity, mark rest as Default
-            if (n>0) push(out, base, base + n, TokenKind::Default);
-            return state;
-        }
-    }
+	// Triple-quoted string continuation uses in_raw_string with raw_delim either "'''" or "\"\"\""
+	if (state.in_raw_string && (state.raw_delim == "'''" || state.raw_delim == "\"\"\"")) {
+		auto pos = s.find(state.raw_delim);
+		if (pos == std::string::npos) {
+			push(out, 0, n, TokenKind::String);
+			return state; // still inside
+		} else {
+			int end = static_cast<int>(pos + static_cast<int>(state.raw_delim.size()));
+			push(out, 0, end, TokenKind::String);
+			// remainder processed normally
+			s                   = s.substr(end);
+			n                   = static_cast<int>(s.size());
+			state.in_raw_string = false;
+			state.raw_delim.clear();
+			// Continue parsing remainder as a separate small loop
+			int base = end;
+			// original offset, but we already emitted to 'out' with base=0; following spans should be from 'end'
+			// For simplicity, mark rest as Default
+			if (n > 0)
+				push(out, base, base + n, TokenKind::Default);
+			return state;
+		}
+	}
 
-    int i = 0;
-    // Detect comment start '#', ignoring inside strings
-    while (i < n) {
-        char c = s[i];
-        if (c==' '||c=='\t') { int j=i+1; while (j<n && (s[j]==' '||s[j]=='\t')) ++j; push(out,i,j,TokenKind::Whitespace); i=j; continue; }
-        if (c=='#') { push(out,i,n,TokenKind::Comment); break; }
-        // Strings: triple quotes and single-line
-        if (c=='"' || c=='\'') {
-            char q=c;
-            // triple?
-            if (i+2 < n && s[i+1]==q && s[i+2]==q) {
-                std::string delim(3, q);
-                int j = i+3; // search for closing triple
-                auto pos = s.find(delim, static_cast<std::size_t>(j));
-                if (pos == std::string::npos) {
-                    push(out,i,n,TokenKind::String);
-                    state.in_raw_string = true; state.raw_delim = delim; return state;
-                } else {
-                    int end = static_cast<int>(pos + 3);
-                    push(out,i,end,TokenKind::String); i=end; continue;
-                }
-            } else {
-                int j=i+1; bool esc=false; while (j<n) { char d=s[j++]; if (esc){esc=false; continue;} if (d=='\\'){esc=true; continue;} if (d==q) break; }
-                push(out,i,j,TokenKind::String); i=j; continue;
-            }
-        }
-        if (std::isdigit(static_cast<unsigned char>(c))) { int j=i+1; while (j<n && (std::isalnum(static_cast<unsigned char>(s[j]))||s[j]=='.'||s[j]=='_' )) ++j; push(out,i,j,TokenKind::Number); i=j; continue; }
-        if (is_ident_start(c)) { int j=i+1; while (j<n && is_ident_char(s[j])) ++j; std::string id=s.substr(i,j-i); TokenKind k=TokenKind::Identifier; if (kws_.count(id)) k=TokenKind::Keyword; push(out,i,j,k); i=j; continue; }
-        if (std::ispunct(static_cast<unsigned char>(c))) { TokenKind k=TokenKind::Operator; if (c==':'||c==','||c=='('||c==')'||c=='['||c==']') k=TokenKind::Punctuation; push(out,i,i+1,k); ++i; continue; }
-        push(out,i,i+1,TokenKind::Default); ++i;
-    }
-    return state;
+	int i = 0;
+	// Detect comment start '#', ignoring inside strings
+	while (i < n) {
+		char c = s[i];
+		if (c == ' ' || c == '\t') {
+			int j = i + 1;
+			while (j < n && (s[j] == ' ' || s[j] == '\t'))
+				++j;
+			push(out, i, j, TokenKind::Whitespace);
+			i = j;
+			continue;
+		}
+		if (c == '#') {
+			push(out, i, n, TokenKind::Comment);
+			break;
+		}
+		// Strings: triple quotes and single-line
+		if (c == '"' || c == '\'') {
+			char q = c;
+			// triple?
+			if (i + 2 < n && s[i + 1] == q && s[i + 2] == q) {
+				std::string delim(3, q);
+				int j    = i + 3; // search for closing triple
+				auto pos = s.find(delim, static_cast<std::size_t>(j));
+				if (pos == std::string::npos) {
+					push(out, i, n, TokenKind::String);
+					state.in_raw_string = true;
+					state.raw_delim     = delim;
+					return state;
+				} else {
+					int end = static_cast<int>(pos + 3);
+					push(out, i, end, TokenKind::String);
+					i = end;
+					continue;
+				}
+			} else {
+				int j    = i + 1;
+				bool esc = false;
+				while (j < n) {
+					char d = s[j++];
+					if (esc) {
+						esc = false;
+						continue;
+					}
+					if (d == '\\') {
+						esc = true;
+						continue;
+					}
+					if (d == q)
+						break;
+				}
+				push(out, i, j, TokenKind::String);
+				i = j;
+				continue;
+			}
+		}
+		if (std::isdigit(static_cast<unsigned char>(c))) {
+			int j = i + 1;
+			while (j < n && (std::isalnum(static_cast<unsigned char>(s[j])) || s[j] == '.' || s[j] == '_'))
+				++j;
+			push(out, i, j, TokenKind::Number);
+			i = j;
+			continue;
+		}
+		if (is_ident_start(c)) {
+			int j = i + 1;
+			while (j < n && is_ident_char(s[j]))
+				++j;
+			std::string id = s.substr(i, j - i);
+			TokenKind k    = TokenKind::Identifier;
+			if (kws_.count(id))
+				k = TokenKind::Keyword;
+			push(out, i, j, k);
+			i = j;
+			continue;
+		}
+		if (std::ispunct(static_cast<unsigned char>(c))) {
+			TokenKind k = TokenKind::Operator;
+			if (c == ':' || c == ',' || c == '(' || c == ')' || c == '[' || c == ']')
+				k = TokenKind::Punctuation;
+			push(out, i, i + 1, k);
+			++i;
+			continue;
+		}
+		push(out, i, i + 1, TokenKind::Default);
+		++i;
+	}
+	return state;
 }
-
-} // namespace kte
+} // namespace kte
\ No newline at end of file
diff --git a/PythonHighlighter.h b/PythonHighlighter.h
index d7d2d3c..6057cb5 100644
--- a/PythonHighlighter.h
+++ b/PythonHighlighter.h
@@ -5,14 +5,16 @@
 #include <unordered_set>
 
 namespace kte {
-
 class PythonHighlighter final : public StatefulHighlighter {
 public:
-    PythonHighlighter();
-    void HighlightLine(const Buffer &buf, int row, std::vector<HighlightSpan> &out) const override;
-    LineState HighlightLineStateful(const Buffer &buf, int row, const LineState &prev, std::vector<HighlightSpan> &out) const override;
-private:
-    std::unordered_set<std::string> kws_;
-};
+	PythonHighlighter();
 
-} // namespace kte
+	void HighlightLine(const Buffer &buf, int row, std::vector<HighlightSpan> &out) const override;
+
+	LineState HighlightLineStateful(const Buffer &buf, int row, const LineState &prev,
+	                                std::vector<HighlightSpan> &out) const override;
+
+private:
+	std::unordered_set<std::string> kws_;
+};
+} // namespace kte
\ No newline at end of file
diff --git a/RustHighlighter.cc b/RustHighlighter.cc
index 8e51007..fa49409 100644
--- a/RustHighlighter.cc
+++ b/RustHighlighter.cc
@@ -3,37 +3,143 @@
 #include <cctype>
 
 namespace kte {
+static void
+push(std::vector<HighlightSpan> &out, int a, int b, TokenKind k)
+{
+	if (b > a)
+		out.push_back({a, b, k});
+}
+
+
+static bool
+is_ident_start(char c)
+{
+	return std::isalpha(static_cast<unsigned char>(c)) || c == '_';
+}
+
+
+static bool
+is_ident_char(char c)
+{
+	return std::isalnum(static_cast<unsigned char>(c)) || c == '_';
+}
 
-static void push(std::vector<HighlightSpan> &out, int a, int b, TokenKind k){ if (b>a) out.push_back({a,b,k}); }
-static bool is_ident_start(char c){ return std::isalpha(static_cast<unsigned char>(c)) || c=='_'; }
-static bool is_ident_char(char c){ return std::isalnum(static_cast<unsigned char>(c)) || c=='_'; }
 
 RustHighlighter::RustHighlighter()
 {
-    const char* kw[] = {"as","break","const","continue","crate","else","enum","extern","false","fn","for","if","impl","in","let","loop","match","mod","move","mut","pub","ref","return","self","Self","static","struct","super","trait","true","type","unsafe","use","where","while","dyn","async","await","try"};
-    for (auto s: kw) kws_.insert(s);
-    const char* tp[] = {"u8","u16","u32","u64","u128","usize","i8","i16","i32","i64","i128","isize","f32","f64","bool","char","str"};
-    for (auto s: tp) types_.insert(s);
+	const char *kw[] = {
+		"as", "break", "const", "continue", "crate", "else", "enum", "extern", "false", "fn", "for", "if",
+		"impl", "in", "let", "loop", "match", "mod", "move", "mut", "pub", "ref", "return", "self", "Self",
+		"static", "struct", "super", "trait", "true", "type", "unsafe", "use", "where", "while", "dyn", "async",
+		"await", "try"
+	};
+	for (auto s: kw)
+		kws_.insert(s);
+	const char *tp[] = {
+		"u8", "u16", "u32", "u64", "u128", "usize", "i8", "i16", "i32", "i64", "i128", "isize", "f32", "f64",
+		"bool", "char", "str"
+	};
+	for (auto s: tp)
+		types_.insert(s);
 }
 
-void RustHighlighter::HighlightLine(const Buffer &buf, int row, std::vector<HighlightSpan> &out) const
+
+void
+RustHighlighter::HighlightLine(const Buffer &buf, int row, std::vector<HighlightSpan> &out) const
 {
-    const auto &rows = buf.Rows();
-    if (row < 0 || static_cast<std::size_t>(row) >= rows.size()) return;
-    std::string s = static_cast<std::string>(rows[static_cast<std::size_t>(row)]);
-    int n = static_cast<int>(s.size());
-    int i = 0;
-    while (i < n) {
-        char c = s[i];
-        if (c==' '||c=='\t') { int j=i+1; while (j<n && (s[j]==' '||s[j]=='\t')) ++j; push(out,i,j,TokenKind::Whitespace); i=j; continue; }
-        if (c=='/' && i+1<n && s[i+1]=='/') { push(out,i,n,TokenKind::Comment); break; }
-        if (c=='/' && i+1<n && s[i+1]=='*') { int j=i+2; bool closed=false; while (j+1<=n) { if (j+1<n && s[j]=='*' && s[j+1]=='/') { j+=2; closed=true; break; } ++j; } if (!closed) { push(out,i,n,TokenKind::Comment); break; } else { push(out,i,j,TokenKind::Comment); i=j; continue; } }
-        if (c=='"') { int j=i+1; bool esc=false; while (j<n){ char d=s[j++]; if (esc){esc=false; continue;} if (d=='\\'){esc=true; continue;} if (d=='"') break; } push(out,i,j,TokenKind::String); i=j; continue; }
-        if (std::isdigit(static_cast<unsigned char>(c))) { int j=i+1; while (j<n && (std::isalnum(static_cast<unsigned char>(s[j]))||s[j]=='.'||s[j]=='_' )) ++j; push(out,i,j,TokenKind::Number); i=j; continue; }
-        if (is_ident_start(c)) { int j=i+1; while (j<n && is_ident_char(s[j])) ++j; std::string id=s.substr(i,j-i); TokenKind k=TokenKind::Identifier; if (kws_.count(id)) k=TokenKind::Keyword; else if (types_.count(id)) k=TokenKind::Type; push(out,i,j,k); i=j; continue; }
-        if (std::ispunct(static_cast<unsigned char>(c))) { TokenKind k=TokenKind::Operator; if (c==';'||c==','||c=='('||c==')'||c=='{'||c=='}'||c=='['||c==']') k=TokenKind::Punctuation; push(out,i,i+1,k); ++i; continue; }
-        push(out,i,i+1,TokenKind::Default); ++i;
-    }
+	const auto &rows = buf.Rows();
+	if (row < 0 || static_cast<std::size_t>(row) >= rows.size())
+		return;
+	std::string s = static_cast<std::string>(rows[static_cast<std::size_t>(row)]);
+	int n         = static_cast<int>(s.size());
+	int i         = 0;
+	while (i < n) {
+		char c = s[i];
+		if (c == ' ' || c == '\t') {
+			int j = i + 1;
+			while (j < n && (s[j] == ' ' || s[j] == '\t'))
+				++j;
+			push(out, i, j, TokenKind::Whitespace);
+			i = j;
+			continue;
+		}
+		if (c == '/' && i + 1 < n && s[i + 1] == '/') {
+			push(out, i, n, TokenKind::Comment);
+			break;
+		}
+		if (c == '/' && i + 1 < n && s[i + 1] == '*') {
+			int j       = i + 2;
+			bool closed = false;
+			while (j + 1 <= n) {
+				if (j + 1 < n && s[j] == '*' && s[j + 1] == '/') {
+					j += 2;
+					closed = true;
+					break;
+				}
+				++j;
+			}
+			if (!closed) {
+				push(out, i, n, TokenKind::Comment);
+				break;
+			} else {
+				push(out, i, j, TokenKind::Comment);
+				i = j;
+				continue;
+			}
+		}
+		if (c == '"') {
+			int j    = i + 1;
+			bool esc = false;
+			while (j < n) {
+				char d = s[j++];
+				if (esc) {
+					esc = false;
+					continue;
+				}
+				if (d == '\\') {
+					esc = true;
+					continue;
+				}
+				if (d == '"')
+					break;
+			}
+			push(out, i, j, TokenKind::String);
+			i = j;
+			continue;
+		}
+		if (std::isdigit(static_cast<unsigned char>(c))) {
+			int j = i + 1;
+			while (j < n && (std::isalnum(static_cast<unsigned char>(s[j])) || s[j] == '.' || s[j] == '_'))
+				++j;
+			push(out, i, j, TokenKind::Number);
+			i = j;
+			continue;
+		}
+		if (is_ident_start(c)) {
+			int j = i + 1;
+			while (j < n && is_ident_char(s[j]))
+				++j;
+			std::string id = s.substr(i, j - i);
+			TokenKind k    = TokenKind::Identifier;
+			if (kws_.count(id))
+				k = TokenKind::Keyword;
+			else if (types_.count(id))
+				k = TokenKind::Type;
+			push(out, i, j, k);
+			i = j;
+			continue;
+		}
+		if (std::ispunct(static_cast<unsigned char>(c))) {
+			TokenKind k = TokenKind::Operator;
+			if (c == ';' || c == ',' || c == '(' || c == ')' || c == '{' || c == '}' || c == '[' || c ==
+			    ']')
+				k = TokenKind::Punctuation;
+			push(out, i, i + 1, k);
+			++i;
+			continue;
+		}
+		push(out, i, i + 1, TokenKind::Default);
+		++i;
+	}
 }
-
-} // namespace kte
+} // namespace kte
\ No newline at end of file
diff --git a/RustHighlighter.h b/RustHighlighter.h
index 6b75c77..9b03e49 100644
--- a/RustHighlighter.h
+++ b/RustHighlighter.h
@@ -5,14 +5,14 @@
 #include <unordered_set>
 
 namespace kte {
-
 class RustHighlighter final : public LanguageHighlighter {
 public:
-    RustHighlighter();
-    void HighlightLine(const Buffer &buf, int row, std::vector<HighlightSpan> &out) const override;
-private:
-    std::unordered_set<std::string> kws_;
-    std::unordered_set<std::string> types_;
-};
+	RustHighlighter();
 
-} // namespace kte
+	void HighlightLine(const Buffer &buf, int row, std::vector<HighlightSpan> &out) const override;
+
+private:
+	std::unordered_set<std::string> kws_;
+	std::unordered_set<std::string> types_;
+};
+} // namespace kte
\ No newline at end of file
diff --git a/ShellHighlighter.cc b/ShellHighlighter.cc
index 2061601..a261f0c 100644
--- a/ShellHighlighter.cc
+++ b/ShellHighlighter.cc
@@ -3,41 +3,103 @@
 #include <cctype>
 
 namespace kte {
-
-static void push(std::vector<HighlightSpan> &out, int a, int b, TokenKind k){ if (b>a) out.push_back({a,b,k}); }
-
-void ShellHighlighter::HighlightLine(const Buffer &buf, int row, std::vector<HighlightSpan> &out) const
+static void
+push(std::vector<HighlightSpan> &out, int a, int b, TokenKind k)
 {
-    const auto &rows = buf.Rows();
-    if (row < 0 || static_cast<std::size_t>(row) >= rows.size()) return;
-    std::string s = static_cast<std::string>(rows[static_cast<std::size_t>(row)]);
-    int n = static_cast<int>(s.size());
-    int i = 0;
-    // if first non-space is '#', whole line is comment
-    int bol = 0; while (bol < n && (s[bol]==' '||s[bol]=='\t')) ++bol;
-    if (bol < n && s[bol] == '#') { push(out, bol, n, TokenKind::Comment); if (bol>0) push(out,0,bol,TokenKind::Whitespace); return; }
-    while (i < n) {
-        char c = s[i];
-        if (c == ' ' || c == '\t') { int j=i+1; while (j<n && (s[j]==' '||s[j]=='\t')) ++j; push(out,i,j,TokenKind::Whitespace); i=j; continue; }
-        if (c == '#') { push(out, i, n, TokenKind::Comment); break; }
-        if (c == '\'' || c == '"') {
-            char q = c; int j = i+1; bool esc=false; while (j<n) { char d=s[j++]; if (q=='"') { if (esc) {esc=false; continue;} if (d=='\\'){esc=true; continue;} if (d=='"') break; } else { if (d=='\'') break; } }
-            push(out,i,j,TokenKind::String); i=j; continue;
-        }
-        // simple keywords
-        if (std::isalpha(static_cast<unsigned char>(c))) {
-            int j=i+1; while (j<n && (std::isalnum(static_cast<unsigned char>(s[j]))||s[j]=='_')) ++j; std::string id=s.substr(i,j-i);
-            static const char* kws[] = {"if","then","fi","for","in","do","done","case","esac","while","function","elif","else"};
-            bool kw=false; for (auto k: kws) if (id==k) { kw=true; break; }
-            push(out,i,j, kw?TokenKind::Keyword:TokenKind::Identifier); i=j; continue;
-        }
-        if (std::ispunct(static_cast<unsigned char>(c))) {
-            TokenKind k = TokenKind::Operator;
-            if (c=='('||c==')'||c=='{'||c=='}'||c==','||c==';') k=TokenKind::Punctuation;
-            push(out,i,i+1,k); ++i; continue;
-        }
-        push(out,i,i+1,TokenKind::Default); ++i;
-    }
+	if (b > a)
+		out.push_back({a, b, k});
 }
 
-} // namespace kte
+
+void
+ShellHighlighter::HighlightLine(const Buffer &buf, int row, std::vector<HighlightSpan> &out) const
+{
+	const auto &rows = buf.Rows();
+	if (row < 0 || static_cast<std::size_t>(row) >= rows.size())
+		return;
+	std::string s = static_cast<std::string>(rows[static_cast<std::size_t>(row)]);
+	int n         = static_cast<int>(s.size());
+	int i         = 0;
+	// if first non-space is '#', whole line is comment
+	int bol = 0;
+	while (bol < n && (s[bol] == ' ' || s[bol] == '\t'))
+		++bol;
+	if (bol < n && s[bol] == '#') {
+		push(out, bol, n, TokenKind::Comment);
+		if (bol > 0)
+			push(out, 0, bol, TokenKind::Whitespace);
+		return;
+	}
+	while (i < n) {
+		char c = s[i];
+		if (c == ' ' || c == '\t') {
+			int j = i + 1;
+			while (j < n && (s[j] == ' ' || s[j] == '\t'))
+				++j;
+			push(out, i, j, TokenKind::Whitespace);
+			i = j;
+			continue;
+		}
+		if (c == '#') {
+			push(out, i, n, TokenKind::Comment);
+			break;
+		}
+		if (c == '\'' || c == '"') {
+			char q   = c;
+			int j    = i + 1;
+			bool esc = false;
+			while (j < n) {
+				char d = s[j++];
+				if (q == '"') {
+					if (esc) {
+						esc = false;
+						continue;
+					}
+					if (d == '\\') {
+						esc = true;
+						continue;
+					}
+					if (d == '"')
+						break;
+				} else {
+					if (d == '\'')
+						break;
+				}
+			}
+			push(out, i, j, TokenKind::String);
+			i = j;
+			continue;
+		}
+		// simple keywords
+		if (std::isalpha(static_cast<unsigned char>(c))) {
+			int j = i + 1;
+			while (j < n && (std::isalnum(static_cast<unsigned char>(s[j])) || s[j] == '_'))
+				++j;
+			std::string id           = s.substr(i, j - i);
+			static const char *kws[] = {
+				"if", "then", "fi", "for", "in", "do", "done", "case", "esac", "while", "function",
+				"elif", "else"
+			};
+			bool kw = false;
+			for (auto k: kws)
+				if (id == k) {
+					kw = true;
+					break;
+				}
+			push(out, i, j, kw ? TokenKind::Keyword : TokenKind::Identifier);
+			i = j;
+			continue;
+		}
+		if (std::ispunct(static_cast<unsigned char>(c))) {
+			TokenKind k = TokenKind::Operator;
+			if (c == '(' || c == ')' || c == '{' || c == '}' || c == ',' || c == ';')
+				k = TokenKind::Punctuation;
+			push(out, i, i + 1, k);
+			++i;
+			continue;
+		}
+		push(out, i, i + 1, TokenKind::Default);
+		++i;
+	}
+}
+} // namespace kte
\ No newline at end of file
diff --git a/ShellHighlighter.h b/ShellHighlighter.h
index c819bb7..f0f4cd1 100644
--- a/ShellHighlighter.h
+++ b/ShellHighlighter.h
@@ -4,10 +4,8 @@
 #include "LanguageHighlighter.h"
 
 namespace kte {
-
 class ShellHighlighter final : public LanguageHighlighter {
 public:
-    void HighlightLine(const Buffer &buf, int row, std::vector<HighlightSpan> &out) const override;
+	void HighlightLine(const Buffer &buf, int row, std::vector<HighlightSpan> &out) const override;
 };
-
-} // namespace kte
+} // namespace kte
\ No newline at end of file
diff --git a/TerminalRenderer.cc b/TerminalRenderer.cc
index 9858602..8a3d60a 100644
--- a/TerminalRenderer.cc
+++ b/TerminalRenderer.cc
@@ -42,18 +42,18 @@ TerminalRenderer::Draw(Editor &ed)
 		std::size_t coloffs = buf->Coloffs();
 
 		const int tabw = 8;
-  // Phase 3: prefetch visible viewport highlights (current terminal area)
-        if (buf->SyntaxEnabled() && buf->Highlighter() && buf->Highlighter()->HasHighlighter()) {
-            int fr = static_cast<int>(rowoffs);
-            int rc = std::max(0, content_rows);
-            buf->Highlighter()->PrefetchViewport(*buf, fr, rc, buf->Version());
-        }
+		// Phase 3: prefetch visible viewport highlights (current terminal area)
+		if (buf->SyntaxEnabled() && buf->Highlighter() && buf->Highlighter()->HasHighlighter()) {
+			int fr = static_cast<int>(rowoffs);
+			int rc = std::max(0, content_rows);
+			buf->Highlighter()->PrefetchViewport(*buf, fr, rc, buf->Version());
+		}
 
-        for (int r = 0; r < content_rows; ++r) {
-            move(r, 0);
-            std::size_t li         = rowoffs + static_cast<std::size_t>(r);
-            std::size_t render_col = 0;
-            std::size_t src_i      = 0;
+		for (int r = 0; r < content_rows; ++r) {
+			move(r, 0);
+			std::size_t li         = rowoffs + static_cast<std::size_t>(r);
+			std::size_t render_col = 0;
+			std::size_t src_i      = 0;
 			// Compute matches for this line if search highlighting is active
 			bool search_mode = ed.SearchActive() && !ed.SearchQuery().empty();
 			std::vector<std::pair<std::size_t, std::size_t> > ranges; // [start, end)
@@ -105,49 +105,53 @@ TerminalRenderer::Draw(Editor &ed)
 			bool hl_on                 = false;
 			bool cur_on                = false;
 			int written                = 0;
-   if (li < lines.size()) {
-                std::string line = static_cast<std::string>(lines[li]);
-                src_i            = 0;
-                render_col       = 0;
-                // Syntax highlighting: fetch per-line spans
-                const kte::LineHighlight *lh_ptr = nullptr;
-                if (buf->SyntaxEnabled() && buf->Highlighter() && buf->Highlighter()->HasHighlighter()) {
-                    lh_ptr = &buf->Highlighter()->GetLine(*buf, static_cast<int>(li), buf->Version());
-                }
-                auto token_at = [&](std::size_t src_index) -> kte::TokenKind {
-                    if (!lh_ptr) return kte::TokenKind::Default;
-                    for (const auto &sp: lh_ptr->spans) {
-                        if (static_cast<int>(src_index) >= sp.col_start && static_cast<int>(src_index) < sp.col_end)
-                            return sp.kind;
-                    }
-                    return kte::TokenKind::Default;
-                };
-                auto apply_token_attr = [&](kte::TokenKind k) {
-                    // Map to simple attributes; search highlight uses A_STANDOUT which takes precedence below
-                    attrset(A_NORMAL);
-                    switch (k) {
-                        case kte::TokenKind::Keyword:
-                        case kte::TokenKind::Type:
-                        case kte::TokenKind::Constant:
-                        case kte::TokenKind::Function:
-                            attron(A_BOLD);
-                            break;
-                        case kte::TokenKind::Comment:
-                            attron(A_DIM);
-                            break;
-                        case kte::TokenKind::String:
-                        case kte::TokenKind::Char:
-                        case kte::TokenKind::Number:
-                            // standout a bit using A_UNDERLINE if available
-                            attron(A_UNDERLINE);
-                            break;
-                        default:
-                            break;
-                    }
-                };
-                while (written < cols) {
-                    char ch       = ' ';
-                    bool from_src = false;
+			if (li < lines.size()) {
+				std::string line = static_cast<std::string>(lines[li]);
+				src_i            = 0;
+				render_col       = 0;
+				// Syntax highlighting: fetch per-line spans
+				const kte::LineHighlight *lh_ptr = nullptr;
+				if (buf->SyntaxEnabled() && buf->Highlighter() && buf->Highlighter()->
+				    HasHighlighter()) {
+					lh_ptr = &buf->Highlighter()->GetLine(
+						*buf, static_cast<int>(li), buf->Version());
+				}
+				auto token_at = [&](std::size_t src_index) -> kte::TokenKind {
+					if (!lh_ptr)
+						return kte::TokenKind::Default;
+					for (const auto &sp: lh_ptr->spans) {
+						if (static_cast<int>(src_index) >= sp.col_start && static_cast<int>(
+							    src_index) < sp.col_end)
+							return sp.kind;
+					}
+					return kte::TokenKind::Default;
+				};
+				auto apply_token_attr = [&](kte::TokenKind k) {
+					// Map to simple attributes; search highlight uses A_STANDOUT which takes precedence below
+					attrset(A_NORMAL);
+					switch (k) {
+					case kte::TokenKind::Keyword:
+					case kte::TokenKind::Type:
+					case kte::TokenKind::Constant:
+					case kte::TokenKind::Function:
+						attron(A_BOLD);
+						break;
+					case kte::TokenKind::Comment:
+						attron(A_DIM);
+						break;
+					case kte::TokenKind::String:
+					case kte::TokenKind::Char:
+					case kte::TokenKind::Number:
+						// standout a bit using A_UNDERLINE if available
+						attron(A_UNDERLINE);
+						break;
+					default:
+						break;
+					}
+				};
+				while (written < cols) {
+					char ch       = ' ';
+					bool from_src = false;
 					if (src_i < line.size()) {
 						unsigned char c = static_cast<unsigned char>(line[src_i]);
 						if (c == '\t') {
@@ -166,45 +170,45 @@ TerminalRenderer::Draw(Editor &ed)
 								next_tab -= to_skip;
 							}
 							// Now render visible spaces
-       while (next_tab > 0 && written < cols) {
-                                bool in_hl  = search_mode && is_src_in_hl(src_i);
-                                bool in_cur =
-                                    has_current && li == cur_my && src_i >= cur_mx
-                                    && src_i < cur_mend;
-                                // Toggle highlight attributes
-                                int attr = 0;
-                                if (in_hl)
-                                    attr |= A_STANDOUT;
-                                if (in_cur)
-                                    attr |= A_BOLD;
-                                if ((attr & A_STANDOUT) && !hl_on) {
-                                    attron(A_STANDOUT);
-                                    hl_on = true;
-                                }
-                                if (!(attr & A_STANDOUT) && hl_on) {
-                                    attroff(A_STANDOUT);
-                                    hl_on = false;
-                                }
-                                if ((attr & A_BOLD) && !cur_on) {
-                                    attron(A_BOLD);
-                                    cur_on = true;
-                                }
-                                if (!(attr & A_BOLD) && cur_on) {
-                                    attroff(A_BOLD);
-                                    cur_on = false;
-                                }
-                                // Apply syntax attribute only if not in search highlight
-                                if (!in_hl) {
-                                    apply_token_attr(token_at(src_i));
-                                }
-                                addch(' ');
-                                ++written;
-                                ++render_col;
-                                --next_tab;
-                            }
-                            ++src_i;
-                            continue;
-                        } else {
+							while (next_tab > 0 && written < cols) {
+								bool in_hl  = search_mode && is_src_in_hl(src_i);
+								bool in_cur =
+									has_current && li == cur_my && src_i >= cur_mx
+									&& src_i < cur_mend;
+								// Toggle highlight attributes
+								int attr = 0;
+								if (in_hl)
+									attr |= A_STANDOUT;
+								if (in_cur)
+									attr |= A_BOLD;
+								if ((attr & A_STANDOUT) && !hl_on) {
+									attron(A_STANDOUT);
+									hl_on = true;
+								}
+								if (!(attr & A_STANDOUT) && hl_on) {
+									attroff(A_STANDOUT);
+									hl_on = false;
+								}
+								if ((attr & A_BOLD) && !cur_on) {
+									attron(A_BOLD);
+									cur_on = true;
+								}
+								if (!(attr & A_BOLD) && cur_on) {
+									attroff(A_BOLD);
+									cur_on = false;
+								}
+								// Apply syntax attribute only if not in search highlight
+								if (!in_hl) {
+									apply_token_attr(token_at(src_i));
+								}
+								addch(' ');
+								++written;
+								++render_col;
+								--next_tab;
+							}
+							++src_i;
+							continue;
+						} else {
 							// normal char
 							if (render_col < coloffs) {
 								++render_col;
@@ -219,49 +223,49 @@ TerminalRenderer::Draw(Editor &ed)
 						ch       = ' ';
 						from_src = false;
 					}
-     bool in_hl  = search_mode && from_src && is_src_in_hl(src_i);
-     bool in_cur =
-         has_current && li == cur_my && from_src && src_i >= cur_mx && src_i <
-         cur_mend;
-     if (in_hl && !hl_on) {
-         attron(A_STANDOUT);
-         hl_on = true;
-     }
-     if (!in_hl && hl_on) {
-         attroff(A_STANDOUT);
-         hl_on = false;
-     }
-     if (in_cur && !cur_on) {
-         attron(A_BOLD);
-         cur_on = true;
-     }
-     if (!in_cur && cur_on) {
-         attroff(A_BOLD);
-         cur_on = false;
-     }
-     if (!in_hl && from_src) {
-         apply_token_attr(token_at(src_i));
-     }
-     addch(static_cast<unsigned char>(ch));
-     ++written;
-     ++render_col;
-     if (from_src)
-         ++src_i;
+					bool in_hl  = search_mode && from_src && is_src_in_hl(src_i);
+					bool in_cur =
+						has_current && li == cur_my && from_src && src_i >= cur_mx && src_i <
+						cur_mend;
+					if (in_hl && !hl_on) {
+						attron(A_STANDOUT);
+						hl_on = true;
+					}
+					if (!in_hl && hl_on) {
+						attroff(A_STANDOUT);
+						hl_on = false;
+					}
+					if (in_cur && !cur_on) {
+						attron(A_BOLD);
+						cur_on = true;
+					}
+					if (!in_cur && cur_on) {
+						attroff(A_BOLD);
+						cur_on = false;
+					}
+					if (!in_hl && from_src) {
+						apply_token_attr(token_at(src_i));
+					}
+					addch(static_cast<unsigned char>(ch));
+					++written;
+					++render_col;
+					if (from_src)
+						++src_i;
 					if (src_i >= line.size() && written >= cols)
 						break;
 				}
 			}
-            if (hl_on) {
-                attroff(A_STANDOUT);
-                hl_on = false;
-            }
-            if (cur_on) {
-                attroff(A_BOLD);
-                cur_on = false;
-            }
-            attrset(A_NORMAL);
-            clrtoeol();
-        }
+			if (hl_on) {
+				attroff(A_STANDOUT);
+				hl_on = false;
+			}
+			if (cur_on) {
+				attroff(A_BOLD);
+				cur_on = false;
+			}
+			attrset(A_NORMAL);
+			clrtoeol();
+		}
 
 		// Place terminal cursor at logical position accounting for tabs and coloffs
 		std::size_t cy = buf->Cury();
@@ -464,4 +468,4 @@ TerminalRenderer::Draw(Editor &ed)
 	}
 
 	refresh();
-}
+}
\ No newline at end of file
diff --git a/TreeSitterHighlighter.cc b/TreeSitterHighlighter.cc
index 0c63327..64c75d4 100644
--- a/TreeSitterHighlighter.cc
+++ b/TreeSitterHighlighter.cc
@@ -6,41 +6,46 @@
 #include <utility>
 
 namespace kte {
+TreeSitterHighlighter::TreeSitterHighlighter(const TSLanguage *lang, std::string filetype)
+	: language_(lang), filetype_(std::move(filetype)) {}
 
-TreeSitterHighlighter::TreeSitterHighlighter(const TSLanguage* lang, std::string filetype)
-    : language_(lang), filetype_(std::move(filetype))
-{
-}
 
 TreeSitterHighlighter::~TreeSitterHighlighter()
 {
-    disposeParser();
+	disposeParser();
 }
 
-void TreeSitterHighlighter::ensureParsed(const Buffer& /*buf*/) const
+
+void
+TreeSitterHighlighter::ensureParsed(const Buffer & /*buf*/) const
 {
-    // Intentionally a stub to avoid pulling the Tree-sitter API and library by default.
-    // In future, when linking against tree-sitter, initialize parser_, set language_,
-    // and build tree_ from the buffer contents.
+	// Intentionally a stub to avoid pulling the Tree-sitter API and library by default.
+	// In future, when linking against tree-sitter, initialize parser_, set language_,
+	// and build tree_ from the buffer contents.
 }
 
-void TreeSitterHighlighter::disposeParser() const
+
+void
+TreeSitterHighlighter::disposeParser() const
 {
-    // Stub; nothing to dispose when not actually creating parser/tree
+	// Stub; nothing to dispose when not actually creating parser/tree
 }
 
-void TreeSitterHighlighter::HighlightLine(const Buffer &/*buf*/, int /*row*/, std::vector<HighlightSpan> &/*out*/) const
+
+void
+TreeSitterHighlighter::HighlightLine(const Buffer &/*buf*/, int /*row*/, std::vector<HighlightSpan> &/*out*/) const
 {
-    // For now, no-op. When tree-sitter is wired, map nodes to TokenKind spans per line.
+	// For now, no-op. When tree-sitter is wired, map nodes to TokenKind spans per line.
 }
 
-std::unique_ptr<LanguageHighlighter> CreateTreeSitterHighlighter(const char* filetype,
-                                                                 const void* (*get_lang)())
+
+std::unique_ptr<LanguageHighlighter>
+CreateTreeSitterHighlighter(const char *filetype,
+                            const void * (*get_lang)())
 {
-    const auto* lang = reinterpret_cast<const TSLanguage*>(get_lang ? get_lang() : nullptr);
-    return std::make_unique<TreeSitterHighlighter>(lang, filetype ? std::string(filetype) : std::string());
+	const auto *lang = reinterpret_cast<const TSLanguage *>(get_lang ? get_lang() : nullptr);
+	return std::make_unique < TreeSitterHighlighter > (lang, filetype ? std::string(filetype) : std::string());
 }
-
 } // namespace kte
 
-#endif // KTE_ENABLE_TREESITTER
+#endif // KTE_ENABLE_TREESITTER
\ No newline at end of file
diff --git a/TreeSitterHighlighter.h b/TreeSitterHighlighter.h
index 7cd53d9..e27df8d 100644
--- a/TreeSitterHighlighter.h
+++ b/TreeSitterHighlighter.h
@@ -17,32 +17,32 @@ struct TSTree;
 }
 
 namespace kte {
-
 // A minimal adapter that uses Tree-sitter to parse the whole buffer and then, for now,
 // does very limited token classification. This acts as a scaffold for future richer
 // queries. If no queries are provided, it currently produces no spans (safe fallback).
 class TreeSitterHighlighter : public LanguageHighlighter {
 public:
-    explicit TreeSitterHighlighter(const TSLanguage* lang, std::string filetype);
-    ~TreeSitterHighlighter() override;
+	explicit TreeSitterHighlighter(const TSLanguage *lang, std::string filetype);
 
-    void HighlightLine(const Buffer &buf, int row, std::vector<HighlightSpan> &out) const override;
+	~TreeSitterHighlighter() override;
+
+	void HighlightLine(const Buffer &buf, int row, std::vector<HighlightSpan> &out) const override;
 
 private:
-    const TSLanguage* language_{nullptr};
-    std::string filetype_;
-    // Lazy parser to avoid startup cost; mutable to allow creation in const method
-    mutable TSParser* parser_{nullptr};
-    mutable TSTree* tree_{nullptr};
+	const TSLanguage *language_{nullptr};
+	std::string filetype_;
+	// Lazy parser to avoid startup cost; mutable to allow creation in const method
+	mutable TSParser *parser_{nullptr};
+	mutable TSTree *tree_{nullptr};
 
-    void ensureParsed(const Buffer& buf) const;
-    void disposeParser() const;
+	void ensureParsed(const Buffer &buf) const;
+
+	void disposeParser() const;
 };
 
 // Factory used by HighlighterRegistry when registering via RegisterTreeSitter.
-std::unique_ptr<LanguageHighlighter> CreateTreeSitterHighlighter(const char* filetype,
-                                                                 const void* (*get_lang)());
-
+std::unique_ptr<LanguageHighlighter> CreateTreeSitterHighlighter(const char *filetype,
+                                                                 const void * (*get_lang)());
 } // namespace kte
 
-#endif // KTE_ENABLE_TREESITTER
+#endif // KTE_ENABLE_TREESITTER
\ No newline at end of file
diff --git a/lsp/BufferChangeTracker.cc b/lsp/BufferChangeTracker.cc
new file mode 100644
index 0000000..cd126fb
--- /dev/null
+++ b/lsp/BufferChangeTracker.cc
@@ -0,0 +1,49 @@
+/*
+ * BufferChangeTracker.cc - minimal initial implementation
+ */
+#include "BufferChangeTracker.h"
+#include "../Buffer.h"
+
+namespace kte::lsp {
+BufferChangeTracker::BufferChangeTracker(const Buffer *buffer)
+	: buffer_(buffer) {}
+
+
+void
+BufferChangeTracker::recordInsertion(int /*row*/, int /*col*/, const std::string &/*text*/)
+{
+	// For Phase 1–2 bring-up, coalesce to full-document changes
+	fullChangePending_ = true;
+	++version_;
+}
+
+
+void
+BufferChangeTracker::recordDeletion(int /*row*/, int /*col*/, std::size_t /*len*/)
+{
+	fullChangePending_ = true;
+	++version_;
+}
+
+
+std::vector<TextDocumentContentChangeEvent>
+BufferChangeTracker::getChanges() const
+{
+	std::vector<TextDocumentContentChangeEvent> v;
+	if (!buffer_)
+		return v;
+	if (fullChangePending_) {
+		TextDocumentContentChangeEvent ev;
+		ev.text = buffer_->FullText();
+		v.push_back(std::move(ev));
+	}
+	return v;
+}
+
+
+void
+BufferChangeTracker::clearChanges()
+{
+	fullChangePending_ = false;
+}
+} // namespace kte::lsp
\ No newline at end of file
diff --git a/lsp/BufferChangeTracker.h b/lsp/BufferChangeTracker.h
new file mode 100644
index 0000000..d8a5ead
--- /dev/null
+++ b/lsp/BufferChangeTracker.h
@@ -0,0 +1,44 @@
+/*
+ * BufferChangeTracker.h - integrates with Buffer to accumulate LSP-friendly changes
+ */
+#ifndef KTE_BUFFER_CHANGE_TRACKER_H
+#define KTE_BUFFER_CHANGE_TRACKER_H
+
+#include <memory>
+#include <vector>
+#include <string>
+
+#include "LspTypes.h"
+
+class Buffer; // forward declare from core
+
+namespace kte::lsp {
+class BufferChangeTracker {
+public:
+	explicit BufferChangeTracker(const Buffer *buffer);
+
+	// Called by Buffer on each edit operation
+	void recordInsertion(int row, int col, const std::string &text);
+
+	void recordDeletion(int row, int col, std::size_t len);
+
+	// Get accumulated changes since last sync
+	std::vector<TextDocumentContentChangeEvent> getChanges() const;
+
+	// Clear changes after sending to LSP
+	void clearChanges();
+
+	// Get current document version for LSP
+	int getVersion() const
+	{
+		return version_;
+	}
+
+private:
+	const Buffer *buffer_   = nullptr;
+	bool fullChangePending_ = false;
+	int version_            = 0;
+};
+} // namespace kte::lsp
+
+#endif // KTE_BUFFER_CHANGE_TRACKER_H
\ No newline at end of file
diff --git a/lsp/Diagnostic.h b/lsp/Diagnostic.h
new file mode 100644
index 0000000..cbdcd03
--- /dev/null
+++ b/lsp/Diagnostic.h
@@ -0,0 +1,37 @@
+/*
+ * Diagnostic.h - LSP diagnostic data types
+ */
+#ifndef KTE_LSP_DIAGNOSTIC_H
+#define KTE_LSP_DIAGNOSTIC_H
+
+#include <optional>
+#include <string>
+#include <vector>
+
+#include "LspTypes.h"
+
+namespace kte::lsp {
+enum class DiagnosticSeverity {
+	Error = 1,
+	Warning = 2,
+	Information = 3,
+	Hint = 4
+};
+
+struct DiagnosticRelatedInformation {
+	std::string uri; // related location URI
+	Range range; // related range
+	std::string message;
+};
+
+struct Diagnostic {
+	Range range{};
+	DiagnosticSeverity severity{DiagnosticSeverity::Information};
+	std::optional<std::string> code;
+	std::optional<std::string> source;
+	std::string message;
+	std::vector<DiagnosticRelatedInformation> relatedInfo;
+};
+} // namespace kte::lsp
+
+#endif // KTE_LSP_DIAGNOSTIC_H
\ No newline at end of file
diff --git a/lsp/DiagnosticDisplay.h b/lsp/DiagnosticDisplay.h
new file mode 100644
index 0000000..62f87db
--- /dev/null
+++ b/lsp/DiagnosticDisplay.h
@@ -0,0 +1,30 @@
+/*
+ * DiagnosticDisplay.h - Abstract interface for showing diagnostics
+ */
+#ifndef KTE_LSP_DIAGNOSTIC_DISPLAY_H
+#define KTE_LSP_DIAGNOSTIC_DISPLAY_H
+
+#include <string>
+#include <vector>
+
+#include "Diagnostic.h"
+
+namespace kte::lsp {
+class DiagnosticDisplay {
+public:
+	virtual ~DiagnosticDisplay() = default;
+
+	virtual void updateDiagnostics(const std::string &uri,
+	                               const std::vector<Diagnostic> &diagnostics) = 0;
+
+	virtual void showInlineDiagnostic(const Diagnostic &diagnostic) = 0;
+
+	virtual void showDiagnosticList(const std::vector<Diagnostic> &diagnostics) = 0;
+
+	virtual void hideDiagnosticList() = 0;
+
+	virtual void updateStatusBar(int errorCount, int warningCount) = 0;
+};
+} // namespace kte::lsp
+
+#endif // KTE_LSP_DIAGNOSTIC_DISPLAY_H
\ No newline at end of file
diff --git a/lsp/DiagnosticStore.cc b/lsp/DiagnosticStore.cc
new file mode 100644
index 0000000..2a4a3c7
--- /dev/null
+++ b/lsp/DiagnosticStore.cc
@@ -0,0 +1,123 @@
+/*
+ * DiagnosticStore.cc - implementation
+ */
+#include "DiagnosticStore.h"
+
+#include <algorithm>
+
+namespace kte::lsp {
+void
+DiagnosticStore::setDiagnostics(const std::string &uri, std::vector<Diagnostic> diagnostics)
+{
+	diagnostics_[uri] = std::move(diagnostics);
+}
+
+
+const std::vector<Diagnostic> &
+DiagnosticStore::getDiagnostics(const std::string &uri) const
+{
+	auto it = diagnostics_.find(uri);
+	static const std::vector<Diagnostic> kEmpty;
+	if (it == diagnostics_.end())
+		return kEmpty;
+	return it->second;
+}
+
+
+std::vector<Diagnostic>
+DiagnosticStore::getDiagnosticsAtLine(const std::string &uri, int line) const
+{
+	std::vector<Diagnostic> out;
+	auto it = diagnostics_.find(uri);
+	if (it == diagnostics_.end())
+		return out;
+	out.reserve(it->second.size());
+	for (const auto &d: it->second) {
+		if (containsLine(d.range, line))
+			out.push_back(d);
+	}
+	return out;
+}
+
+
+std::optional<Diagnostic>
+DiagnosticStore::getDiagnosticAtPosition(const std::string &uri, Position pos) const
+{
+	auto it = diagnostics_.find(uri);
+	if (it == diagnostics_.end())
+		return std::nullopt;
+	for (const auto &d: it->second) {
+		if (containsPosition(d.range, pos))
+			return d;
+	}
+	return std::nullopt;
+}
+
+
+void
+DiagnosticStore::clear(const std::string &uri)
+{
+	diagnostics_.erase(uri);
+}
+
+
+void
+DiagnosticStore::clearAll()
+{
+	diagnostics_.clear();
+}
+
+
+int
+DiagnosticStore::getErrorCount(const std::string &uri) const
+{
+	auto it = diagnostics_.find(uri);
+	if (it == diagnostics_.end())
+		return 0;
+	int count = 0;
+	for (const auto &d: it->second) {
+		if (d.severity == DiagnosticSeverity::Error)
+			++count;
+	}
+	return count;
+}
+
+
+int
+DiagnosticStore::getWarningCount(const std::string &uri) const
+{
+	auto it = diagnostics_.find(uri);
+	if (it == diagnostics_.end())
+		return 0;
+	int count = 0;
+	for (const auto &d: it->second) {
+		if (d.severity == DiagnosticSeverity::Warning)
+			++count;
+	}
+	return count;
+}
+
+
+bool
+DiagnosticStore::containsLine(const Range &r, int line)
+{
+	return (line > r.start.line || line == r.start.line) &&
+	       (line < r.end.line || line == r.end.line);
+}
+
+
+bool
+DiagnosticStore::containsPosition(const Range &r, const Position &p)
+{
+	if (p.line < r.start.line || p.line > r.end.line)
+		return false;
+	if (r.start.line == r.end.line) {
+		return p.line == r.start.line && p.character >= r.start.character && p.character <= r.end.character;
+	}
+	if (p.line == r.start.line)
+		return p.character >= r.start.character;
+	if (p.line == r.end.line)
+		return p.character <= r.end.character;
+	return true; // between start and end lines
+}
+} // namespace kte::lsp
\ No newline at end of file
diff --git a/lsp/DiagnosticStore.h b/lsp/DiagnosticStore.h
new file mode 100644
index 0000000..2396106
--- /dev/null
+++ b/lsp/DiagnosticStore.h
@@ -0,0 +1,42 @@
+/*
+ * DiagnosticStore.h - Central storage for diagnostics by document URI
+ */
+#ifndef KTE_LSP_DIAGNOSTIC_STORE_H
+#define KTE_LSP_DIAGNOSTIC_STORE_H
+
+#include <optional>
+#include <string>
+#include <unordered_map>
+#include <vector>
+
+#include "Diagnostic.h"
+
+namespace kte::lsp {
+class DiagnosticStore {
+public:
+	void setDiagnostics(const std::string &uri, std::vector<Diagnostic> diagnostics);
+
+	const std::vector<Diagnostic> &getDiagnostics(const std::string &uri) const;
+
+	std::vector<Diagnostic> getDiagnosticsAtLine(const std::string &uri, int line) const;
+
+	std::optional<Diagnostic> getDiagnosticAtPosition(const std::string &uri, Position pos) const;
+
+	void clear(const std::string &uri);
+
+	void clearAll();
+
+	int getErrorCount(const std::string &uri) const;
+
+	int getWarningCount(const std::string &uri) const;
+
+private:
+	std::unordered_map<std::string, std::vector<Diagnostic> > diagnostics_;
+
+	static bool containsLine(const Range &r, int line);
+
+	static bool containsPosition(const Range &r, const Position &p);
+};
+} // namespace kte::lsp
+
+#endif // KTE_LSP_DIAGNOSTIC_STORE_H
\ No newline at end of file
diff --git a/lsp/JsonRpcTransport.cc b/lsp/JsonRpcTransport.cc
new file mode 100644
index 0000000..e343108
--- /dev/null
+++ b/lsp/JsonRpcTransport.cc
@@ -0,0 +1,19 @@
+/*
+ * JsonRpcTransport.cc - placeholder
+ */
+#include "JsonRpcTransport.h"
+
+namespace kte::lsp {
+void
+JsonRpcTransport::send(const std::string &/*method*/, const std::string &/*payload*/)
+{
+	// stub: no-op
+}
+
+
+std::optional<JsonRpcMessage>
+JsonRpcTransport::read()
+{
+	return std::nullopt; // stub
+}
+} // namespace kte::lsp
\ No newline at end of file
diff --git a/lsp/JsonRpcTransport.h b/lsp/JsonRpcTransport.h
new file mode 100644
index 0000000..87aad05
--- /dev/null
+++ b/lsp/JsonRpcTransport.h
@@ -0,0 +1,29 @@
+/*
+ * JsonRpcTransport.h - placeholder transport for JSON-RPC over stdio (stub)
+ */
+#ifndef KTE_JSON_RPC_TRANSPORT_H
+#define KTE_JSON_RPC_TRANSPORT_H
+
+#include <optional>
+#include <string>
+
+namespace kte::lsp {
+struct JsonRpcMessage {
+	std::string raw; // raw JSON payload (stub)
+};
+
+class JsonRpcTransport {
+public:
+	JsonRpcTransport() = default;
+
+	~JsonRpcTransport() = default;
+
+	// Send a method call (request or notification) - stub does nothing
+	void send(const std::string &method, const std::string &payload);
+
+	// Blocking read next message (stub => returns nullopt)
+	std::optional<JsonRpcMessage> read();
+};
+} // namespace kte::lsp
+
+#endif // KTE_JSON_RPC_TRANSPORT_H
\ No newline at end of file
diff --git a/lsp/LspClient.h b/lsp/LspClient.h
new file mode 100644
index 0000000..bd7432b
--- /dev/null
+++ b/lsp/LspClient.h
@@ -0,0 +1,61 @@
+/*
+ * LspClient.h - Core LSP client abstraction (initial stub)
+ */
+#ifndef KTE_LSP_CLIENT_H
+#define KTE_LSP_CLIENT_H
+
+#include <functional>
+#include <memory>
+#include <optional>
+#include <string>
+#include <vector>
+
+#include "LspTypes.h"
+
+namespace kte::lsp {
+// Callback types (stubs for future phases)
+using CompletionCallback = std::function<void()>;
+using HoverCallback      = std::function<void()>;
+using LocationCallback   = std::function<void()>;
+
+class LspClient {
+public:
+	virtual ~LspClient() = default;
+
+	// Lifecycle
+	virtual bool initialize(const std::string &rootPath) = 0;
+
+	virtual void shutdown() = 0;
+
+	// Document Synchronization
+	virtual void didOpen(const std::string &uri, const std::string &languageId,
+	                     int version, const std::string &text) = 0;
+
+	virtual void didChange(const std::string &uri, int version,
+	                       const std::vector<TextDocumentContentChangeEvent> &changes) = 0;
+
+	virtual void didClose(const std::string &uri) = 0;
+
+	virtual void didSave(const std::string &uri) = 0;
+
+	// Language Features (not yet implemented)
+	virtual void completion(const std::string &, Position,
+	                        CompletionCallback) {}
+
+
+	virtual void hover(const std::string &, Position,
+	                   HoverCallback) {}
+
+
+	virtual void definition(const std::string &, Position,
+	                        LocationCallback) {}
+
+
+	// Process Management
+	virtual bool isRunning() const = 0;
+
+	virtual std::string getServerName() const = 0;
+};
+} // namespace kte::lsp
+
+#endif // KTE_LSP_CLIENT_H
\ No newline at end of file
diff --git a/lsp/LspManager.cc b/lsp/LspManager.cc
new file mode 100644
index 0000000..c07f4bf
--- /dev/null
+++ b/lsp/LspManager.cc
@@ -0,0 +1,326 @@
+/*
+ * LspManager.cc - central coordination of LSP servers and diagnostics
+ */
+
+#include "LspManager.h"
+
+#include <algorithm>
+#include <cctype>
+#include <filesystem>
+#include <utility>
+
+#include "../Buffer.h"
+#include "../Editor.h"
+#include "BufferChangeTracker.h"
+#include "LspProcessClient.h"
+
+namespace fs = std::filesystem;
+
+namespace kte::lsp {
+LspManager::LspManager(Editor *editor, DiagnosticDisplay *display)
+	: editor_(editor), display_(display)
+{
+	// Pre-populate with sensible default server configs
+	registerDefaultServers();
+}
+
+
+void
+LspManager::registerServer(const std::string &languageId, const LspServerConfig &config)
+{
+	serverConfigs_[languageId] = config;
+}
+
+
+bool
+LspManager::startServerForBuffer(Buffer *buffer)
+{
+	const auto lang = getLanguageId(buffer);
+	if (lang.empty())
+		return false;
+
+	if (servers_.find(lang) != servers_.end() && servers_[lang]->isRunning()) {
+		return true;
+	}
+
+	auto it = serverConfigs_.find(lang);
+	if (it == serverConfigs_.end()) {
+		return false;
+	}
+
+	const auto &cfg = it->second;
+	// Respect autostart for automatic starts on buffer open
+	if (!cfg.autostart) {
+		return false;
+	}
+	auto client = std::make_unique<LspProcessClient>(cfg.command, cfg.args);
+	// Determine root as parent of file for now; future: walk rootPatterns
+	std::string rootPath;
+	if (!buffer->Filename().empty()) {
+		fs::path p(buffer->Filename());
+		rootPath = p.has_parent_path() ? p.parent_path().string() : std::string{};
+	}
+	if (!client->initialize(rootPath)) {
+		return false;
+	}
+	servers_[lang] = std::move(client);
+	return true;
+}
+
+
+void
+LspManager::stopServer(const std::string &languageId)
+{
+	auto it = servers_.find(languageId);
+	if (it != servers_.end()) {
+		it->second->shutdown();
+		servers_.erase(it);
+	}
+}
+
+
+void
+LspManager::stopAllServers()
+{
+	for (auto &kv: servers_) {
+		kv.second->shutdown();
+	}
+	servers_.clear();
+}
+
+
+void
+LspManager::onBufferOpened(Buffer *buffer)
+{
+	if (!startServerForBuffer(buffer))
+		return;
+	auto *client = ensureServerForLanguage(getLanguageId(buffer));
+	if (!client)
+		return;
+
+	const auto uri         = getUri(buffer);
+	const auto lang        = getLanguageId(buffer);
+	const int version      = static_cast<int>(buffer->Version());
+	const std::string text = buffer->FullText();
+	client->didOpen(uri, lang, version, text);
+}
+
+
+void
+LspManager::onBufferChanged(Buffer *buffer)
+{
+	auto *client = ensureServerForLanguage(getLanguageId(buffer));
+	if (!client)
+		return;
+	const auto uri = getUri(buffer);
+	int version    = static_cast<int>(buffer->Version());
+
+	std::vector<TextDocumentContentChangeEvent> changes;
+	if (auto *tracker = buffer->GetChangeTracker()) {
+		changes = tracker->getChanges();
+		tracker->clearChanges();
+		version = tracker->getVersion();
+	} else {
+		// Fallback: full document change
+		TextDocumentContentChangeEvent ev;
+		ev.range.reset();
+		ev.text = buffer->FullText();
+		changes.push_back(std::move(ev));
+	}
+	client->didChange(uri, version, changes);
+}
+
+
+void
+LspManager::onBufferClosed(Buffer *buffer)
+{
+	auto *client = ensureServerForLanguage(getLanguageId(buffer));
+	if (!client)
+		return;
+	client->didClose(getUri(buffer));
+	// Clear diagnostics for this file
+	diagnosticStore_.clear(getUri(buffer));
+}
+
+
+void
+LspManager::onBufferSaved(Buffer *buffer)
+{
+	auto *client = ensureServerForLanguage(getLanguageId(buffer));
+	if (!client)
+		return;
+	client->didSave(getUri(buffer));
+}
+
+
+void
+LspManager::requestCompletion(Buffer *buffer, Position pos, CompletionCallback callback)
+{
+	if (auto *client = ensureServerForLanguage(getLanguageId(buffer))) {
+		client->completion(getUri(buffer), pos, std::move(callback));
+	}
+}
+
+
+void
+LspManager::requestHover(Buffer *buffer, Position pos, HoverCallback callback)
+{
+	if (auto *client = ensureServerForLanguage(getLanguageId(buffer))) {
+		client->hover(getUri(buffer), pos, std::move(callback));
+	}
+}
+
+
+void
+LspManager::requestDefinition(Buffer *buffer, Position pos, LocationCallback callback)
+{
+	if (auto *client = ensureServerForLanguage(getLanguageId(buffer))) {
+		client->definition(getUri(buffer), pos, std::move(callback));
+	}
+}
+
+
+void
+LspManager::handleDiagnostics(const std::string &uri, const std::vector<Diagnostic> &diagnostics)
+{
+	diagnosticStore_.setDiagnostics(uri, diagnostics);
+	if (display_) {
+		display_->updateDiagnostics(uri, diagnostics);
+		display_->updateStatusBar(diagnosticStore_.getErrorCount(uri), diagnosticStore_.getWarningCount(uri));
+	}
+}
+
+
+std::string
+LspManager::getLanguageId(Buffer *buffer)
+{
+	// Prefer explicit filetype if set
+	const auto &ft = buffer->Filetype();
+	if (!ft.empty())
+		return ft;
+	// Otherwise map extension
+	fs::path p(buffer->Filename());
+	return extToLanguageId(p.extension().string());
+}
+
+
+std::string
+LspManager::getUri(Buffer *buffer)
+{
+	const auto &path = buffer->Filename();
+	if (path.empty()) {
+		// Untitled buffer: use a pseudo-URI
+		return std::string("untitled:") + std::to_string(reinterpret_cast<std::uintptr_t>(buffer));
+	}
+	fs::path p(path);
+	p = fs::weakly_canonical(p);
+#ifdef _WIN32
+	// rudimentary file URI; future: robust encoding
+	return std::string("file:/") + p.string();
+#else
+	return std::string("file://") + p.string();
+#endif
+}
+
+
+std::string
+LspManager::extToLanguageId(const std::string &ext)
+{
+	std::string e = ext;
+	if (!e.empty() && e[0] == '.')
+		e.erase(0, 1);
+	std::string lower;
+	lower.resize(e.size());
+	std::transform(e.begin(), e.end(), lower.begin(), [](unsigned char c) {
+		return static_cast<char>(std::tolower(c));
+	});
+	if (lower == "rs")
+		return "rust";
+	if (lower == "c" || lower == "cc" || lower == "cpp" || lower == "h" || lower == "hpp")
+		return "cpp";
+	if (lower == "go")
+		return "go";
+	if (lower == "py")
+		return "python";
+	if (lower == "js")
+		return "javascript";
+	if (lower == "ts")
+		return "typescript";
+	if (lower == "json")
+		return "json";
+	if (lower == "sh" || lower == "bash" || lower == "zsh")
+		return "shell";
+	if (lower == "md")
+		return "markdown";
+	return lower; // best-effort
+}
+
+
+LspClient *
+LspManager::ensureServerForLanguage(const std::string &languageId)
+{
+	auto it = servers_.find(languageId);
+	if (it != servers_.end() && it->second && it->second->isRunning()) {
+		return it->second.get();
+	}
+	// Attempt to start from config if present
+	auto cfg = serverConfigs_.find(languageId);
+	if (cfg == serverConfigs_.end())
+		return nullptr;
+	auto client = std::make_unique<LspProcessClient>(cfg->second.command, cfg->second.args);
+	if (!client->initialize(""))
+		return nullptr;
+	auto *ret            = client.get();
+	servers_[languageId] = std::move(client);
+	return ret;
+}
+
+
+void
+LspManager::registerDefaultServers()
+{
+	// Import defaults and register by inferred languageId from file patterns
+	for (const auto &cfg: GetDefaultServerConfigs()) {
+		if (cfg.filePatterns.empty()) {
+			// If no patterns, we can't infer; skip
+			continue;
+		}
+		for (const auto &pat: cfg.filePatterns) {
+			const auto lang = patternToLanguageId(pat);
+			if (lang.empty())
+				continue;
+			// Don't overwrite if user already registered a server for this lang
+			if (serverConfigs_.find(lang) == serverConfigs_.end()) {
+				serverConfigs_.emplace(lang, cfg);
+			}
+		}
+	}
+}
+
+
+std::string
+LspManager::patternToLanguageId(const std::string &pattern)
+{
+	// Expect patterns like "*.rs", "*.cpp" etc. Extract extension and reuse extToLanguageId
+	// Find last '.' in the pattern and take substring after it, stripping any trailing wildcards
+	std::string ext;
+	// Common case: starts with *.
+	auto pos = pattern.rfind('.');
+	if (pos != std::string::npos && pos + 1 < pattern.size()) {
+		ext = pattern.substr(pos + 1);
+		// Remove any trailing wildcard characters
+		while (!ext.empty() && (ext.back() == '*' || ext.back() == '?')) {
+			ext.pop_back();
+		}
+	} else {
+		// No dot; try to treat whole pattern as extension after trimming leading '*'
+		ext = pattern;
+		while (!ext.empty() && (ext.front() == '*' || ext.front() == '.')) {
+			ext.erase(ext.begin());
+		}
+	}
+	if (ext.empty())
+		return {};
+	return extToLanguageId(ext);
+}
+} // namespace kte::lsp
diff --git a/lsp/LspManager.h b/lsp/LspManager.h
new file mode 100644
index 0000000..d42580b
--- /dev/null
+++ b/lsp/LspManager.h
@@ -0,0 +1,85 @@
+/*
+ * LspManager.h - central coordination of LSP servers and diagnostics
+ */
+#ifndef KTE_LSP_MANAGER_H
+#define KTE_LSP_MANAGER_H
+
+#include <memory>
+#include <string>
+#include <unordered_map>
+
+class Buffer; // fwd
+class Editor; // fwd
+
+#include "DiagnosticDisplay.h"
+#include "DiagnosticStore.h"
+#include "LspClient.h"
+#include "LspServerConfig.h"
+
+namespace kte::lsp {
+class LspManager {
+public:
+	explicit LspManager(Editor *editor, DiagnosticDisplay *display);
+
+	// Server management
+	void registerServer(const std::string &languageId, const LspServerConfig &config);
+
+	bool startServerForBuffer(Buffer *buffer);
+
+	void stopServer(const std::string &languageId);
+
+	void stopAllServers();
+
+	// Document sync (to be called by editor/buffer events)
+	void onBufferOpened(Buffer *buffer);
+
+	void onBufferChanged(Buffer *buffer);
+
+	void onBufferClosed(Buffer *buffer);
+
+	void onBufferSaved(Buffer *buffer);
+
+	// Feature requests (stubs)
+	void requestCompletion(Buffer *buffer, Position pos, CompletionCallback callback);
+
+	void requestHover(Buffer *buffer, Position pos, HoverCallback callback);
+
+	void requestDefinition(Buffer *buffer, Position pos, LocationCallback callback);
+
+	// Diagnostics (public so LspClient impls can forward results here later)
+	void handleDiagnostics(const std::string &uri, const std::vector<Diagnostic> &diagnostics);
+
+
+	void setDebugLogging(bool enabled)
+	{
+		debug_ = enabled;
+	}
+
+private:
+	[[maybe_unused]] Editor *editor_{}; // non-owning
+	DiagnosticDisplay *display_{}; // non-owning
+	DiagnosticStore diagnosticStore_{};
+
+	// Key: languageId → client
+	std::unordered_map<std::string, std::unique_ptr<LspClient> > servers_;
+	std::unordered_map<std::string, LspServerConfig> serverConfigs_;
+
+	// Helpers
+	static std::string getLanguageId(Buffer *buffer);
+
+	static std::string getUri(Buffer *buffer);
+
+	static std::string extToLanguageId(const std::string &ext);
+
+	LspClient *ensureServerForLanguage(const std::string &languageId);
+
+	bool debug_ = false;
+
+	// Configuration helpers
+	void registerDefaultServers();
+
+	static std::string patternToLanguageId(const std::string &pattern);
+};
+} // namespace kte::lsp
+
+#endif // KTE_LSP_MANAGER_H
\ No newline at end of file
diff --git a/lsp/LspProcessClient.cc b/lsp/LspProcessClient.cc
new file mode 100644
index 0000000..0905ab3
--- /dev/null
+++ b/lsp/LspProcessClient.cc
@@ -0,0 +1,72 @@
+/*
+ * LspProcessClient.cc - initial stub implementation
+ */
+#include "LspProcessClient.h"
+
+namespace kte::lsp {
+LspProcessClient::LspProcessClient(std::string serverCommand, std::vector<std::string> serverArgs)
+	: command_(std::move(serverCommand)), args_(std::move(serverArgs)), transport_(new JsonRpcTransport()) {}
+
+
+LspProcessClient::~LspProcessClient() = default;
+
+
+bool
+LspProcessClient::initialize(const std::string &/*rootPath*/)
+{
+	// Phase 1–2: no real process spawn yet
+	running_ = true;
+	return true;
+}
+
+
+void
+LspProcessClient::shutdown()
+{
+	running_ = false;
+}
+
+
+void
+LspProcessClient::didOpen(const std::string &/*uri*/, const std::string &/*languageId*/,
+                          int /*version*/, const std::string &/*text*/)
+{
+	// Stub: would send textDocument/didOpen
+}
+
+
+void
+LspProcessClient::didChange(const std::string &/*uri*/, int /*version*/,
+                            const std::vector<TextDocumentContentChangeEvent> &/*changes*/)
+{
+	// Stub: would send textDocument/didChange
+}
+
+
+void
+LspProcessClient::didClose(const std::string &/*uri*/)
+{
+	// Stub
+}
+
+
+void
+LspProcessClient::didSave(const std::string &/*uri*/)
+{
+	// Stub
+}
+
+
+bool
+LspProcessClient::isRunning() const
+{
+	return running_;
+}
+
+
+std::string
+LspProcessClient::getServerName() const
+{
+	return command_;
+}
+} // namespace kte::lsp
\ No newline at end of file
diff --git a/lsp/LspProcessClient.h b/lsp/LspProcessClient.h
new file mode 100644
index 0000000..0f78a44
--- /dev/null
+++ b/lsp/LspProcessClient.h
@@ -0,0 +1,47 @@
+/*
+ * LspProcessClient.h - process-based LSP client (initial stub)
+ */
+#ifndef KTE_LSP_PROCESS_CLIENT_H
+#define KTE_LSP_PROCESS_CLIENT_H
+
+#include <memory>
+#include <string>
+#include <vector>
+
+#include "LspClient.h"
+#include "JsonRpcTransport.h"
+
+namespace kte::lsp {
+class LspProcessClient : public LspClient {
+public:
+	LspProcessClient(std::string serverCommand, std::vector<std::string> serverArgs);
+
+	~LspProcessClient() override;
+
+	bool initialize(const std::string &rootPath) override;
+
+	void shutdown() override;
+
+	void didOpen(const std::string &uri, const std::string &languageId,
+	             int version, const std::string &text) override;
+
+	void didChange(const std::string &uri, int version,
+	               const std::vector<TextDocumentContentChangeEvent> &changes) override;
+
+	void didClose(const std::string &uri) override;
+
+	void didSave(const std::string &uri) override;
+
+	bool isRunning() const override;
+
+	std::string getServerName() const override;
+
+private:
+	std::string command_;
+	std::vector<std::string> args_;
+	std::unique_ptr<JsonRpcTransport> transport_;
+	bool running_ = false;
+};
+} // namespace kte::lsp
+
+#endif // KTE_LSP_PROCESS_CLIENT_H
\ No newline at end of file
diff --git a/lsp/LspServerConfig.h b/lsp/LspServerConfig.h
new file mode 100644
index 0000000..308fead
--- /dev/null
+++ b/lsp/LspServerConfig.h
@@ -0,0 +1,47 @@
+/*
+ * LspServerConfig.h - per-language LSP server configuration
+ */
+#ifndef KTE_LSP_SERVER_CONFIG_H
+#define KTE_LSP_SERVER_CONFIG_H
+
+#include <string>
+#include <unordered_map>
+#include <vector>
+
+namespace kte::lsp {
+enum class LspSyncMode {
+	None = 0,
+	Full = 1,
+	Incremental = 2,
+};
+
+struct LspServerConfig {
+	std::string command; // executable name/path
+	std::vector<std::string> args; // CLI args
+	std::vector<std::string> filePatterns; // e.g. {"*.rs"}
+	std::string rootPatterns; // e.g. "Cargo.toml"
+	LspSyncMode preferredSyncMode = LspSyncMode::Incremental;
+	bool autostart                = true;
+	std::unordered_map<std::string, std::string> initializationOptions; // placeholder
+	std::unordered_map<std::string, std::string> settings; // placeholder
+};
+
+// Provide a small set of defaults; callers may ignore
+inline std::vector<LspServerConfig>
+GetDefaultServerConfigs()
+{
+	return std::vector<LspServerConfig>{
+		LspServerConfig{
+			.command = "rust-analyzer", .args = {}, .filePatterns = {"*.rs"}, .rootPatterns = "Cargo.toml"
+		},
+		LspServerConfig{
+			.command = "clangd", .args = {"--background-index"},
+			.filePatterns = {"*.c", "*.cc", "*.cpp", "*.h", "*.hpp"},
+			.rootPatterns = "compile_commands.json"
+		},
+		LspServerConfig{.command = "gopls", .args = {}, .filePatterns = {"*.go"}, .rootPatterns = "go.mod"},
+	};
+}
+} // namespace kte::lsp
+
+#endif // KTE_LSP_SERVER_CONFIG_H
\ No newline at end of file
diff --git a/lsp/LspTypes.h b/lsp/LspTypes.h
new file mode 100644
index 0000000..be37fe5
--- /dev/null
+++ b/lsp/LspTypes.h
@@ -0,0 +1,29 @@
+/*
+ * LspTypes.h - minimal LSP-related data types for initial integration
+ */
+#ifndef KTE_LSP_TYPES_H
+#define KTE_LSP_TYPES_H
+
+#include <cstdint>
+#include <optional>
+#include <string>
+#include <vector>
+
+namespace kte::lsp {
+struct Position {
+	int line      = 0;
+	int character = 0;
+};
+
+struct Range {
+	Position start;
+	Position end;
+};
+
+struct TextDocumentContentChangeEvent {
+	std::optional<Range> range; // if not set, represents full document change
+	std::string text; // new text for the given range
+};
+} // namespace kte::lsp
+
+#endif // KTE_LSP_TYPES_H
\ No newline at end of file
diff --git a/lsp/TerminalDiagnosticDisplay.cc b/lsp/TerminalDiagnosticDisplay.cc
new file mode 100644
index 0000000..e4a8b58
--- /dev/null
+++ b/lsp/TerminalDiagnosticDisplay.cc
@@ -0,0 +1,53 @@
+/*
+ * TerminalDiagnosticDisplay.cc - minimal stub implementation
+ */
+#include "TerminalDiagnosticDisplay.h"
+
+#include "../TerminalRenderer.h"
+
+namespace kte::lsp {
+TerminalDiagnosticDisplay::TerminalDiagnosticDisplay(TerminalRenderer *renderer)
+	: renderer_(renderer) {}
+
+
+void
+TerminalDiagnosticDisplay::updateDiagnostics(const std::string &uri,
+                                             const std::vector<Diagnostic> &diagnostics)
+{
+	(void) uri;
+	(void) diagnostics;
+	// Stub: no rendering yet. Future: gutter markers, underlines, virtual text.
+}
+
+
+void
+TerminalDiagnosticDisplay::showInlineDiagnostic(const Diagnostic &diagnostic)
+{
+	(void) diagnostic;
+	// Stub: show as message line in future.
+}
+
+
+void
+TerminalDiagnosticDisplay::showDiagnosticList(const std::vector<Diagnostic> &diagnostics)
+{
+	(void) diagnostics;
+	// Stub: open a panel/list in future.
+}
+
+
+void
+TerminalDiagnosticDisplay::hideDiagnosticList()
+{
+	// Stub
+}
+
+
+void
+TerminalDiagnosticDisplay::updateStatusBar(int errorCount, int warningCount)
+{
+	(void) errorCount;
+	(void) warningCount;
+	// Stub: integrate with status bar rendering later.
+}
+} // namespace kte::lsp
\ No newline at end of file
diff --git a/lsp/TerminalDiagnosticDisplay.h b/lsp/TerminalDiagnosticDisplay.h
new file mode 100644
index 0000000..a0d1b5c
--- /dev/null
+++ b/lsp/TerminalDiagnosticDisplay.h
@@ -0,0 +1,35 @@
+/*
+ * TerminalDiagnosticDisplay.h - Terminal (ncurses) diagnostics visualization stub
+ */
+#ifndef KTE_LSP_TERMINAL_DIAGNOSTIC_DISPLAY_H
+#define KTE_LSP_TERMINAL_DIAGNOSTIC_DISPLAY_H
+
+#include <string>
+#include <vector>
+
+#include "DiagnosticDisplay.h"
+
+class TerminalRenderer; // fwd
+
+namespace kte::lsp {
+class TerminalDiagnosticDisplay final : public DiagnosticDisplay {
+public:
+	explicit TerminalDiagnosticDisplay(TerminalRenderer *renderer);
+
+	void updateDiagnostics(const std::string &uri,
+	                       const std::vector<Diagnostic> &diagnostics) override;
+
+	void showInlineDiagnostic(const Diagnostic &diagnostic) override;
+
+	void showDiagnosticList(const std::vector<Diagnostic> &diagnostics) override;
+
+	void hideDiagnosticList() override;
+
+	void updateStatusBar(int errorCount, int warningCount) override;
+
+private:
+	[[maybe_unused]] TerminalRenderer *renderer_{}; // non-owning
+};
+} // namespace kte::lsp
+
+#endif // KTE_LSP_TERMINAL_DIAGNOSTIC_DISPLAY_H
\ No newline at end of file