Switch to c++

2025-12-07 17:22:12 +00:00
parent 2927df7710
commit 7acf35c8ea
55 changed files with 3506 additions and 304 deletions
--- a/.gitignore
+++ b/.gitignore
@@ -7,7 +7,10 @@

 .vscode

-tests/tmp_*
+tests/*
+!tests/.keep

 builds/*
 !builds/.keep
+
+src/cpp/__tmp__
--- a/80
+++ b/80
@@ -0,0 +1,80 @@
+SRC_DIR := src
+BIN_DIR := bin
+OBJ_DIR := build
+
+TARGET_DEBUG := $(BIN_DIR)/crib-dbg
+TARGET_RELEASE := $(BIN_DIR)/crib
+
+CXX_DEBUG := g++
+CXX_RELEASE := clang++
+
+CFLAGS_DEBUG := -std=c++20 -Wall -Wextra -O0 -g -fno-inline -gsplit-dwarf
+CFLAGS_RELEASE := -std=c++20 -O3 -march=native -flto=thin \
+	-fno-exceptions -fno-rtti -fstrict-aliasing -ffast-math -funroll-loops \
+	-fomit-frame-pointer -DNDEBUG -s \
+	-mllvm -inline-threshold=10000 \
+	-mllvm -vectorize-loops \
+	-mllvm -force-vector-width=8 \
+	-mllvm -unroll-threshold=500000
+
+UNICODE_SRC := $(wildcard libs/unicode_width/*.c)
+
+UNICODE_OBJ_DEBUG := $(patsubst libs/unicode_width/%.c,$(OBJ_DIR)/debug/unicode_width/%.o,$(UNICODE_SRC))
+UNICODE_OBJ_RELEASE := $(patsubst libs/unicode_width/%.c,$(OBJ_DIR)/release/unicode_width/%.o,$(UNICODE_SRC))
+
+LIBS := \
+	libs/libgrapheme/libgrapheme.a \
+	libs/tree-sitter/libtree-sitter.a \
+	libs/tree-sitter-ruby/libtree-sitter-ruby.a \
+	-lpcre2-8
+
+
+SRC := $(wildcard $(SRC_DIR)/*.cc)
+OBJ_DEBUG := $(patsubst $(SRC_DIR)/%.cc,$(OBJ_DIR)/debug/%.o,$(SRC))
+OBJ_RELEASE := $(patsubst $(SRC_DIR)/%.cc,$(OBJ_DIR)/release/%.o,$(SRC))
+
+DEP_DEBUG := $(OBJ_DEBUG:.o=.d)
+DEP_RELEASE := $(OBJ_RELEASE:.o=.d)
+
+.PHONY: all test release clean
+
+all: debug
+
+test: $(TARGET_DEBUG)
+
+release: $(TARGET_RELEASE)
+
+$(TARGET_DEBUG): $(OBJ_DEBUG) $(UNICODE_OBJ_DEBUG)
+	mkdir -p $(BIN_DIR)
+	$(CXX_DEBUG) $(CFLAGS_DEBUG) -o $@ $^ $(LIBS)
+
+$(TARGET_RELEASE): $(OBJ_RELEASE) $(UNICODE_OBJ_RELEASE)
+	mkdir -p $(BIN_DIR)
+	$(CXX_RELEASE) $(CFLAGS_RELEASE) -o $@ $^ $(LIBS)
+
+# Pattern rules for object files + dependency generation
+$(OBJ_DIR)/debug/%.o: $(SRC_DIR)/%.cc
+	mkdir -p $(dir $@)
+	$(CXX_DEBUG) $(CFLAGS_DEBUG) -MMD -MP -c $< -o $@
+
+$(OBJ_DIR)/release/%.o: $(SRC_DIR)/%.cc
+	mkdir -p $(dir $@)
+	$(CXX_RELEASE) $(CFLAGS_RELEASE) -MMD -MP -c $< -o $@
+
+$(OBJ_DIR)/debug/unicode_width/%.o: libs/unicode_width/%.c
+	mkdir -p $(dir $@)
+	$(CXX_DEBUG) $(CFLAGS_DEBUG) -MMD -MP -c $< -o $@
+
+$(OBJ_DIR)/release/unicode_width/%.o: libs/unicode_width/%.c
+	mkdir -p $(dir $@)
+	$(CXX_RELEASE) $(CFLAGS_RELEASE) -MMD -MP -c $< -o $@
+
+# Include deps if they exist
+DEP_DEBUG += $(UNICODE_OBJ_DEBUG:.o=.d)
+DEP_RELEASE += $(UNICODE_OBJ_RELEASE:.o=.d)
+
+-include $(DEP_DEBUG)
+-include $(DEP_RELEASE)
+
+clean:
+	rm -rf $(OBJ_DIR) $(BIN_DIR)
--- a/old/builds/.keep
+++ b/old/builds/.keep
--- a/old/crib.rb
+++ b/old/crib.rb
@@ -0,0 +1,54 @@
+#!/usr/bin/env ruby
+
+require "ffi"
+require "zlib"
+
+require_relative "../src/ruby/utils"
+require_relative "../src/ruby/mod"
+require_relative "../src/ruby/ts_rb"
+require_relative "../src/ruby/fm"
+require_relative "../src/ruby/editor"
+require_relative "../src/ruby/ide"
+
+$rows, $cols = C.start_screen
+$running = true
+$event_queue = Queue.new
+$folder = Dir.new File.dirname(ARGV[0] || Dir.pwd)
+$threads = []
+
+at_exit do
+  IDE.close
+  C.end_screen
+  puts "Exiting crib.rb"
+end
+
+IDE.start
+
+$threads << Thread.new do
+  loop do
+    sleep 1.0 / 64
+    break unless $running
+    IDE.handle_event $event_queue.pop timeout: 0 until $event_queue.empty?
+    IDE.render
+    C.render
+  end
+end
+
+$threads << Thread.new do
+  loop do
+    sleep 1.0 / 64
+    break unless $running
+    IDE.work!
+  end
+end
+
+$threads << Thread.new do
+  loop do
+    break unless $running
+    event = C.read_key # read_key is blocking
+    $running = false if KEY_TYPE[event[:key_type]] == :char && event[:c] == ctrl_key('q')
+    $event_queue << event
+  end
+end
+
+$threads.each &:join
--- a/old/editor.rb
+++ b/old/editor.rb
@@ -0,0 +1,329 @@
+class Editor
+  attr_accessor :text, :cursor, :selection_start, :filename
+
+  def initialize(filename, x, y, width, height)
+    contents = File.exist?(filename) ? File.read(filename) : "dddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddd"
+    @text = contents.grapheme_clusters
+    @cursor = @text.size
+    @selection_start = 0
+    @scroll = 0
+    @x = x
+    @y = y
+    @width = width
+    @height = height
+    @filename = filename
+    @folds = []
+    @highlights = Array.new(@text.size)
+    @highlight_generation = 0
+    @tree = nil
+    @num_width = (@text.count("\n") + 1).to_s.size + 3
+
+    @parser = C.ts_parser_new
+    @lang_ts = C.tree_sitter_ruby
+    C.ts_parser_set_language @parser, @lang_ts
+    @cached_tree = nil
+    C.load_query "/home/syed/main/crib/grammar/ruby.scm"
+
+    highlight!
+
+    rebuild_folded_lines!
+  end
+
+  def save!
+    File.write @filename, @text.join
+  end
+
+  def highlight!
+    gen = @highlight_generation
+    src = @text.join
+    text_bytes = []
+    byte_offset = 0
+    @text.each do |cluster|
+      text_bytes << byte_offset
+      byte_offset += cluster.bytesize
+    end
+    text_bytes << byte_offset
+    line_map = []
+    line = 0
+    @text.each_with_index do |ch, i|
+      line_map[i] = line
+      line += 1 if ch == "\n"
+    end
+    # TODO: add ts_tree_edit calls in erase/insert
+    count_ptr = FFI::MemoryPointer.new :uint32
+    @cached_tree = C.ts_parser_parse_string @parser, nil, src, src.bytesize
+    root = C.ts_tree_root_node @cached_tree
+    ptr = C.ts_collect_tokens root, count_ptr, @lang_ts, src
+    count = count_ptr.read_uint32
+    ints  = ptr.read_array_of_uint32 count
+    C.free_tokens ptr
+    count_ptr.free
+    C.ts_tree_delete @cached_tree
+    return if gen != @highlight_generation
+    @highlight_generation = 0
+    @highlights = Array.new(@text.size)
+    done_folds = []
+    ints.each_slice(3).map do |start_byte, end_byte, sym_i|
+      start_cluster = byte_to_cluster start_byte, text_bytes
+      end_cluster   = byte_to_cluster end_byte - 1, text_bytes
+      next if start_cluster.nil? || end_cluster.nil?
+      sym = TS_SYMBOL_MAP[sym_i]
+      if sym == "@fold"
+        start_row = line_map[start_cluster]
+        end_row   = line_map[end_cluster]
+        next if start_row == end_row
+        hash_value = Zlib.crc32 @text[start_cluster...end_cluster].join
+        done_folds << hash_value
+        if (f = @folds.find { |f| f.crc32 == hash_value })
+          f.start = start_row
+          f.end = end_row
+        else
+          @folds << Fold.new(start_row, end_row, false, hash_value)
+        end
+        next
+      end
+      hl  = TS_RUBY[sym]
+      next unless hl
+      (start_cluster..end_cluster).each do |i|
+        @highlights[i] = hl if @highlights[i].nil? || @highlights[i].priority < hl.priority
+      end
+    end
+    @folds.select! { |f| done_folds.include? f.crc32 }
+    rebuild_folded_lines!
+  end
+
+  def byte_to_cluster(byte, byte_starts)
+    left = 0
+    right = byte_starts.size - 2
+    while left <= right
+      mid = (left + right) / 2
+      if byte_starts[mid] <= byte && byte < byte_starts[mid + 1]
+        return mid
+      elsif byte < byte_starts[mid]
+        right = mid - 1
+      else
+        left = mid + 1
+      end
+    end
+    nil
+  end
+
+  def erase(x0, x1)
+    return if x0 < 0 || x1 < x0
+    lines_deleted = @text[x0...x1].count "\n"
+    @text[x0...x1] = []
+    @highlights[x0...x1] = []
+    @highlight_generation += 1
+    @folds.map! do |f|
+      if f.start >= @text[...x0].count("\n")
+        f.start -= lines_deleted
+        f.end -= lines_deleted
+      end
+      f
+    end
+    rebuild_folded_lines!
+    @num_width = (@text.count("\n") + 1).to_s.size + 3
+  end
+
+  def insert(x, str)
+    @text.insert x, *str.grapheme_clusters
+    @highlights.insert x, *Array.new(str.grapheme_clusters.size)
+    lines_added = str.count "\n"
+    @folds.map! do |f|
+      if f.start >= @text[...x].count("\n")
+        f.start += lines_added
+        f.end += lines_added
+      end
+      f
+    end
+    rebuild_folded_lines!
+    @highlight_generation += 1
+    @num_width = (@text.count("\n") + 1).to_s.size + 3
+  end
+
+  def move_up!
+    precursor_text = @text[...@cursor]
+    last_newline = precursor_text.rindex "\n"
+    return unless last_newline
+    @preferred_col ||= @cursor - last_newline
+    prev_start = precursor_text[...last_newline].rindex("\n") || -1
+    @cursor = [
+      prev_start + @preferred_col,
+      @text[prev_start + 1..].index("\n")&.+(prev_start + 1) || @text.size
+    ].min
+  end
+
+  def move_down!
+    next_newline = @text[@cursor..].index("\n")&.+(@cursor)
+    return unless next_newline
+    @preferred_col ||= (@cursor - (@text[...@cursor].rindex("\n") || -1)).abs
+    @cursor = [
+      next_newline + @preferred_col,
+      @text[next_newline + 1..].index("\n")&.+(next_newline + 1) || @text.size
+    ].min
+  end
+
+  def move_left!
+    @cursor = [@cursor - 1, 0].max
+    @preferred_col = nil
+  end
+
+  def move_right!
+    @cursor = [@cursor + 1, @text.size].min
+    @preferred_col = nil
+  end
+
+  def cursor_valid?
+    !@folded_lines.include? @text[0...@cursor].count("\n")
+  end
+
+  def handle_event(event)
+    return if event.nil?
+    case KEY_TYPE[event[:key_type]]
+    when :char
+      ch = event[:c].chr
+      ch = "\n" if ch == "\r"
+      if ch == "'"
+        cr = @text[0...@cursor].count("\n")
+        @folds.find { |f| f.active = !f.active if f.start <= cr && f.end >= cr }
+        rebuild_folded_lines!
+      elsif ch == ctrl_key('s').chr
+        save!
+      elsif ch =~ /[[:print:]]|\n/
+        insert @cursor, ch
+        @cursor += 1
+      elsif ch == "\b" || ch == "\x7f"
+        erase @cursor - 1, @cursor
+        @cursor = [@cursor - 1, 0].max
+      end
+      @preferred_col = nil
+    when :special
+      return unless MODIFIER[event[:special_modifier]] == :none
+      case SPECIAL_KEY[event[:special_key]]
+      when :up
+        move_up!
+        move_up! until cursor_valid?
+      when :down
+        move_down!
+        move_down! until cursor_valid?
+      when :left
+        move_left!
+        move_left! until cursor_valid?
+      when :right
+        move_right!
+        move_right! until cursor_valid?
+      when :delete
+        erase @cursor, @cursor + 1
+        @cursor = [@cursor, @text.size].min
+        @preferred_col = nil
+      end
+    end
+    move_right! until cursor_valid?
+    adjust_scroll!
+  end
+
+  def adjust_scroll!
+    cr = cursor_row_visual
+    start = @scroll
+    last = @scroll + @height - 1
+    if cr < start
+      @scroll = cr
+    elsif cr > last
+      @scroll = cr - @height + 1
+    end
+  end
+
+  def cursor_row_visual
+    row = col = 0
+    nc = 0
+    @text.each_with_index do |ch, i|
+      return row if i == @cursor
+      if @folded_lines.include? nc
+        nc += 1 if ch == "\n"
+        next
+      end
+      if ch == "\n"
+        row += 1
+        nc += 1
+        col = 0
+        next
+      end
+      w = C.display_width(ch)
+      if col + w > @width - @num_width
+        row += 1
+        col = 0
+      end
+      col += w
+    end
+    row
+  end
+
+  def rebuild_folded_lines!
+    @folded_lines = Set.new
+    @folds.each do |f|
+      (f.start + 1..f.end).each { |line_num| @folded_lines.add(line_num) } if f.active
+    end
+  end
+
+  def render
+    (0...@height).each { |h| (0...@width).each { |w|
+      C.update @y + h, @x + w, ' ', 0x000000, 0x000000, 0
+    } }
+    row = col = nc = 0
+    cursor_row = cursor_col = nil
+    @text.each_with_index do |ch, i|
+      if @folded_lines.include? nc
+        nc += 1 if ch == "\n"
+        next
+      end
+      if i == @cursor
+        cursor_row = row
+        cursor_col = col
+      end
+      if col == 0
+        color = 0x666666
+        color = 0xFFFFFF if cursor_row == row
+        num = (nc + 1).to_s.rjust @num_width - 1, '👪👩‍💻👨🏿‍🚀🏳️‍🌈🔥🛠️🌍🥶✅❌💡⏰🚀'#ddasasdasda
+        num.each_char.with_index do |c, j|
+          C.update @y + row - @scroll, @x + j, c, color, 0x000000, 0
+        end
+        if (fold = @folds.find { |f| nc == f.start })
+          icon = fold.active ? "" : "" # "" : "" "" : "" "" : "" "" : "" "" : "" "" : "" "" : "" "" : "" "" : "" "" : "" "" : "" "" : "" "" : "" "" : "" "" : "" "" : "" "" : "" "" : "" "" : "" "" : "" "" : "" "" : "" "" : "" "" : "" "" : "" "" : "" "" : "" "" : "" "" : "" "" : "" "" : "" "" : "" "" : "" "" : "" "" : "" "" : "" "" : "" "" : "" "" : "" "" : "" "" : "" "" : "" "" : "" "" : "" "" : "" "" : "" "" : "" "" : "" "" : "" "" : "" "" : "" "" : "" "" : "" "" : ""
+          C.update @y + row - @scroll, @x, icon, 0xFF0000, 0x000000, 0
+        end
+      end
+      if ch == "\n"
+        row += 1
+        nc += 1
+        col = 0
+        next
+      end
+      w = C.display_width(ch)
+      if col + w > @width - @num_width
+        row += 1
+        col = 0
+      end
+      col += w
+      next if row < @scroll
+      break if row - @scroll >= @height
+      fg = 0xFFFFFF
+      bg = 0x000000
+      fl = 0
+      if (h = @highlights[i])
+        fg = h.color_fg
+        bg = h.color_bg
+        fl = h.flags
+      end
+      C.update @y + row - @scroll, @x + @num_width + col - w, ch, fg, bg, fl
+    end
+    if @text[-1] == "\n" || @text.size == 0
+      num = (nc + 1).to_s.rjust @num_width - 1, ' '
+      color = 0x666666
+      color = 0xFFFFFF if (cursor_row || row) == row
+      num.each_char.with_index do |c, j|
+        C.update @y + row - @scroll, @x + j, c, color, 0x000000, 0
+      end
+    end
+    C.set_cursor @y - @scroll + (cursor_row || row), @x + @num_width + (cursor_col || col), 1
+  end
+end
--- a/old/fm.rb
+++ b/old/fm.rb
@@ -0,0 +1,30 @@
+module FileManager
+  @hidden = true
+
+  module_function
+
+  def start(x, y, width, height)
+    @hidden = false
+    @x = x
+    @y = y
+    @width = width
+    @height = height
+  end
+
+  def toggle!
+    @hidden = !@hidden
+  end
+
+  def render
+    return if @hidden
+    (0...@height).each { |h| (0...@width).each { |w|
+      C.update @y + h, @x + w, ' ', 0x000000, 0x000000, 0
+    } }
+    files = $folder.children
+    files.each_with_index do |f, i|
+      f.each_char.with_index do |c, j|
+        C.update @y + i, @x + j, c, 0xFFFFFF, 0x000000, 0
+      end
+    end
+  end
+end
--- a/old/ide.rb
+++ b/old/ide.rb
@@ -0,0 +1,36 @@
+module IDE
+  FM_WIDTH = 20
+
+  module_function
+  
+  def start
+    @editors = {}
+    @u_c = 0
+    editor = Editor.new (ARGV[0] || ""), FM_WIDTH, 0, $cols - FM_WIDTH, $rows
+    @editors[editor.filename || "untitled #{@u_c += 1}"] = editor
+    @selected_editor = @editors.keys.first
+    @focus = :editor
+    FileManager.start 0, 0, FM_WIDTH, $rows
+  end
+
+  def handle_event(event)
+    if @focus == :editor
+      @editors[@selected_editor].handle_event event if @editors.key? @selected_editor
+    elsif @focus == :file_manager
+      # TODO
+    end
+  end
+
+  def render
+    @editors[@selected_editor].render if @editors.key? @selected_editor
+    FileManager.render
+  end
+
+  def work!
+    @editors[@selected_editor].highlight! if @editors.key? @selected_editor
+  end
+
+  def close
+    # TODO
+  end
+end
--- a/old/mod.rb
+++ b/old/mod.rb
@@ -0,0 +1,126 @@
+module C
+  extend FFI::Library
+  ffi_lib File.join(__dir__, "../../libs/tree-sitter/libtree-sitter.so")
+
+  # TSTree and TSParser are opaque pointers
+  typedef :pointer, :tstree
+  typedef :pointer, :tsparser
+
+  # Define TSNode struct
+  class TSNode < FFI::Struct
+    layout :context, [:uint32, 4],
+           :id, :pointer,
+           :tree, :tstree
+  end
+
+  class TSPoint < FFI::Struct
+    layout :row, :uint32,
+           :column, :uint32
+  end
+
+  class TSInputEdit < FFI::Struct
+    layout :start_byte,      :uint32,
+           :old_end_byte,    :uint32,
+           :new_end_byte,    :uint32,
+           :start_point,     TSPoint.by_value,
+           :old_end_point,   TSPoint.by_value,
+           :new_end_point,   TSPoint.by_value
+  end
+
+  class TSTreeCursor < FFI::Struct
+    layout :tree, :pointer,
+           :id, :pointer,
+           :context, [:uint32, 3]
+  end
+
+  attach_function :ts_parser_new, [], :tsparser
+  attach_function :ts_parser_set_language, [:tsparser, :pointer], :bool
+  attach_function :ts_parser_parse_string, [:tsparser, :tstree, :string, :size_t], :tstree, blocking: true
+  attach_function :ts_tree_delete, [:tstree], :void
+
+  attach_function :ts_node_start_byte, [TSNode.by_value], :uint32
+  attach_function :ts_node_end_byte, [TSNode.by_value], :uint32
+  attach_function :ts_node_symbol, [TSNode.by_value], :uint16
+
+  attach_function :ts_tree_edit, [:tstree, TSInputEdit.by_ref], :void
+
+  attach_function :ts_tree_root_node, [:tstree], TSNode.by_value, blocking: true
+
+  attach_function :ts_node_child_count, [TSNode.by_value], :uint32
+  attach_function :ts_node_child, [TSNode.by_value, :uint32], TSNode.by_value
+
+
+
+  # Ruby grammar
+  ffi_lib File.join(__dir__, "../../libs/tree-sitter-ruby/libtree-sitter-ruby.so")
+  attach_function :tree_sitter_ruby, [], :pointer
+
+
+  ffi_lib File.join(__dir__, "../../builds/C-crib.so")
+
+  class KeyEvent < FFI::Struct
+    layout :key_type, :uint8,
+           :c, :char,
+           :special_key, :uint8,
+           :special_modifier, :uint8,
+           :mouse_x, :uint8,
+           :mouse_y, :uint8,
+           :mouse_button, :uint8,
+           :mouse_state, :uint8,
+           :mouse_direction, :uint8,
+           :mouse_modifier, :uint8
+
+    def to_s
+      case KEY_TYPE[self[:key_type]]
+      when :char
+        "#<KeyEvent char=#{self[:c].inspect}>"
+      when :special
+        "#<KeyEvent special key=#{SPECIAL_KEY[self[:special_key]]} mod=#{MODIFIER[self[:special_modifier]]}>"
+      when :mouse
+        "#<KeyEvent mouse x=#{self[:mouse_x]} y=#{self[:mouse_y]} " \
+        "btn=#{MOUSE_BUTTON[self[:mouse_button]]} state=#{MOUSE_STATE[self[:mouse_state]]} " \
+        "scroll_dir=#{SCROLL_DIR[self[:mouse_direction]]} mod=#{MODIFIER[self[:mouse_modifier]]}>"
+      else
+        "#<KeyEvent type=#{self[:key_type]} unknown=true>"
+      end
+    end
+  end
+
+  class Coords < FFI::Struct
+    layout :x, :int,
+           :y, :int
+
+    def to_ary
+      [self[:x], self[:y]]
+    end
+
+    def to_s
+      "#<Coords x=#{self[:x]} y=#{self[:y]}>"
+    end
+  end
+
+  class Size < FFI::Struct
+    layout :rows, :int,
+           :cols, :int
+
+    def to_ary
+      [self[:rows], self[:cols]]
+    end
+
+    def to_s
+      "#<Size rows=#{self[:rows]} cols=#{self[:cols]}>"
+    end
+  end
+
+  attach_function :load_query, [:string], :void
+  attach_function :ts_collect_tokens, [TSNode.by_value, :pointer, :pointer, :string], :pointer, blocking: true
+  attach_function :free_tokens, [:pointer], :void, blocking: true
+  attach_function :start_screen, [], Size.by_value
+  attach_function :end_screen, [], :void
+  attach_function :update, [:int, :int, :string, :uint32, :uint32, :uint8], :void
+  attach_function :render, [], :void, blocking: true
+  attach_function :set_cursor, [:int, :int, :int], :void
+  attach_function :read_key, [], KeyEvent.by_value, blocking: true
+  attach_function :get_size, [], Coords.by_value
+  attach_function :display_width, [:string], :int, blocking: true
+end
--- a/old/ts_rb.rb
+++ b/old/ts_rb.rb
@@ -0,0 +1,57 @@
+query = File.read "/home/syed/main/crib/grammar/ruby.scm"
+
+raw = query.scan(/@[a-zA-Z0-9_.]+/)
+
+seen = {}
+ordered = []
+
+raw.each do |c|
+  next if seen[c]
+  seen[c] = true
+  ordered << c
+end
+
+TS_SYMBOL_MAP = ordered.freeze
+
+spawn "echo \"#{TS_SYMBOL_MAP.sort.join "\n"}\" > /tmp/gg"
+
+TS_RUBY = {
+  "@string.special.symbol" => Highlight.new(0xbd9ae6, 0x000000, CF_NONE, 2),
+  "@comment"               => Highlight.new(0xAAAAAA, 0x000000, CF_ITALIC, 1),
+  "@boolean.true"          => Highlight.new(0x51eeba, 0x000000, CF_NONE, 1),
+  "@boolean.false"         => Highlight.new(0xee513a, 0x000000, CF_NONE, 1),
+  "@constant.nil"          => Highlight.new(0xee8757, 0x000000, CF_NONE, 1),
+  "@constant"              => Highlight.new(0xebda8c, 0x000000, CF_NONE, 1),
+  "@number"                => Highlight.new(0xebda8c, 0x000000, CF_NONE, 2),
+  "@number.float"          => Highlight.new(0xebda8c, 0x000000, CF_NONE, 2),
+  "@constant.builtin"      => Highlight.new(0xfbb152, 0x000000, CF_NONE, 2),
+  "@punctuation.bracket"   => Highlight.new(0xbd9ae6, 0x000000, CF_NONE, 1),
+  "@operator.ligature"     => Highlight.new(0xffffff, 0x000000, CF_ITALIC, 1),
+  "@operator"              => Highlight.new(0xffffff, 0x000000, CF_NONE, 1),
+  "@punctuation.delimiter" => Highlight.new(0xbd9ae6, 0x000000, CF_NONE, 1),
+  "@punctuation.special"   => Highlight.new(0xe6a24c, 0x000000, CF_NONE, 1),
+  "@function"              => Highlight.new(0xaad84c, 0x000000, CF_NONE, 1),
+  "@function.builtin"      => Highlight.new(0xaad84c, 0xFF0000, CF_NONE, 1),
+  "@keyword.import"        => Highlight.new(0xfbb152, 0x000000, CF_NONE, 1),
+  "@function.call"         => Highlight.new(0xff5689, 0x000000, CF_NONE, 1),
+
+  "@keyword"               => Highlight.new(0xfbb152, 0x000000, CF_NONE, 1),
+  "@keyword.conditional"   => Highlight.new(0xfbb152, 0x000000, CF_NONE, 1),
+  "@keyword.control"       => Highlight.new(0xfbb152, 0x000000, CF_NONE, 1),
+  "@keyword.directive"     => Highlight.new(0xfbb152, 0x000000, CF_NONE, 1),
+  "@keyword.exception"     => Highlight.new(0xfbb152, 0x000000, CF_NONE, 1),
+  "@keyword.function"      => Highlight.new(0xfbb152, 0x000000, CF_NONE, 1),
+  "@keyword.operator"      => Highlight.new(0xfbb152, 0x000000, CF_NONE, 1),
+  "@keyword.repeat"        => Highlight.new(0xfbb152, 0x000000, CF_NONE, 1),
+  "@keyword.return"        => Highlight.new(0xfbb152, 0x000000, CF_NONE, 1),
+  "@keyword.type"          => Highlight.new(0xfbb152, 0x000000, CF_NONE, 1),
+  "@label"                 => Highlight.new(0xfbb152, 0x000000, CF_NONE, 1),
+  "@string"                => Highlight.new(0xaad84c, 0x000000, CF_NONE, 1),
+  "@string.escape"         => Highlight.new(0xe6a24c, 0x000000, CF_NONE, 2),
+  "@string.regexp"         => Highlight.new(0xe6a24c, 0x000000, CF_NONE, 2),
+  "@type"                  => Highlight.new(0xaad84c, 0x000000, CF_NONE, 1),
+  "@variable"              => Highlight.new(0xffffff, 0x000000, CF_NONE, 1),
+  "@variable.builtin"      => Highlight.new(0xffffff, 0x000000, CF_NONE, 1),
+  "@variable.member"       => Highlight.new(0xffffff, 0x000000, CF_NONE, 1),
+  "@variable.parameter"    => Highlight.new(0xffffff, 0x000000, CF_NONE, 1),
+}
--- a/src/ruby/utils.rb
+++ b/src/ruby/utils.rb
@@ -1,3 +1,12 @@
+Fold = Struct.new(:start, :end, :active, :crc32)
+Highlight = Struct.new(:color_fg, :color_bg, :flags, :priority)
+Token = Struct.new(:start, :end, :sym)
+
+CF_NONE      = 0b00000000
+CF_ITALIC    = 0b00000001
+CF_BOLD      = 0b00000010
+CF_UNDERLINE = 0b00000100
+
 def ctrl_key(k)
  k.ord & 0x1F
 end
@@ -6,8 +15,9 @@ end
 KEY_TYPE = {
  0 => :char,
  1 => :special,
-  2 => :mouse
-}
+  2 => :mouse,
+  3 => :none
+}.freeze

 # Special keys
 SPECIAL_KEY = {
@@ -16,10 +26,10 @@ SPECIAL_KEY = {
  2 => :left,
  3 => :right,
  4 => :delete
-}
+}.freeze

 # Control key
-KEY_ESC = "\x1b"
+KEY_ESC = "\x1b".freeze

 # Mouse states
 MOUSE_STATE = {
@@ -27,7 +37,7 @@ MOUSE_STATE = {
  1 => :release,
  2 => :drag,
  3 => :scroll
-}
+}.freeze

 # Mouse buttons
 MOUSE_BUTTON = {
@@ -36,7 +46,7 @@ MOUSE_BUTTON = {
  2 => :right,
  3 => :scroll,
  4 => :none
-}
+}.freeze

 # Scroll directions
 SCROLL_DIR = {
@@ -45,12 +55,13 @@ SCROLL_DIR = {
  2 => :left,
  3 => :right,
  4 => :none
-}
+}.freeze

 # Modifiers
 MODIFIER = {
+  0 => :none,
  1 => :alt,
  2 => :cntrl,
  3 => :cntrl_alt,
  4 => :shift
-}
+}.freeze
--- a/bin/crib
+++ b/bin/crib
--- a/bin/crib-dbg
+++ b/bin/crib-dbg
--- a/build/debug/editor.d
+++ b/build/debug/editor.d
@@ -0,0 +1,14 @@
+build/debug/editor.o: src/editor.cc src/../libs/libgrapheme/grapheme.h \
+ src/../include/editor.h \
+ src/../include/../libs/tree-sitter/lib/include/tree_sitter/api.h \
+ src/../include/./rope.h src/../include/./ui.h src/../include/./utils.h \
+ src/../include/ts.h \
+ src/../libs/tree-sitter-ruby/bindings/c/tree-sitter-ruby.h
+src/../libs/libgrapheme/grapheme.h:
+src/../include/editor.h:
+src/../include/../libs/tree-sitter/lib/include/tree_sitter/api.h:
+src/../include/./rope.h:
+src/../include/./ui.h:
+src/../include/./utils.h:
+src/../include/ts.h:
+src/../libs/tree-sitter-ruby/bindings/c/tree-sitter-ruby.h:
--- a/build/debug/editor.dwo
+++ b/build/debug/editor.dwo
--- a/build/debug/input.d
+++ b/build/debug/input.d
@@ -0,0 +1,2 @@
+build/debug/input.o: src/input.cc src/../include/ui.h
+src/../include/ui.h:
--- a/build/debug/input.dwo
+++ b/build/debug/input.dwo
--- a/build/debug/main.d
+++ b/build/debug/main.d
@@ -0,0 +1,12 @@
+build/debug/main.o: src/main.cc src/../include/editor.h \
+ src/../include/../libs/tree-sitter/lib/include/tree_sitter/api.h \
+ src/../include/./rope.h src/../include/./ui.h src/../include/./utils.h \
+ src/../include/ts.h \
+ src/../libs/tree-sitter/lib/include/tree_sitter/api.h
+src/../include/editor.h:
+src/../include/../libs/tree-sitter/lib/include/tree_sitter/api.h:
+src/../include/./rope.h:
+src/../include/./ui.h:
+src/../include/./utils.h:
+src/../include/ts.h:
+src/../libs/tree-sitter/lib/include/tree_sitter/api.h:
--- a/build/debug/main.dwo
+++ b/build/debug/main.dwo
--- a/build/debug/renderer.d
+++ b/build/debug/renderer.d
@@ -0,0 +1,6 @@
+build/debug/renderer.o: src/renderer.cc \
+ src/../libs/libgrapheme/grapheme.h \
+ src/../libs/unicode_width/unicode_width.h src/../include/ui.h
+src/../libs/libgrapheme/grapheme.h:
+src/../libs/unicode_width/unicode_width.h:
+src/../include/ui.h:
--- a/build/debug/renderer.dwo
+++ b/build/debug/renderer.dwo
--- a/build/debug/rope.d
+++ b/build/debug/rope.d
@@ -0,0 +1,2 @@
+build/debug/rope.o: src/rope.cc src/../include/rope.h
+src/../include/rope.h:
--- a/build/debug/rope.dwo
+++ b/build/debug/rope.dwo
--- a/build/debug/ts.d
+++ b/build/debug/ts.d
@@ -0,0 +1,11 @@
+build/debug/ts.o: src/ts.cc src/../include/ts.h src/../include/./editor.h \
+ src/../include/./../libs/tree-sitter/lib/include/tree_sitter/api.h \
+ src/../include/././rope.h src/../include/././ui.h \
+ src/../include/././utils.h src/../include/rope.h
+src/../include/ts.h:
+src/../include/./editor.h:
+src/../include/./../libs/tree-sitter/lib/include/tree_sitter/api.h:
+src/../include/././rope.h:
+src/../include/././ui.h:
+src/../include/././utils.h:
+src/../include/rope.h:
--- a/build/debug/ts.dwo
+++ b/build/debug/ts.dwo
--- a/build/debug/unicode_width/unicode_width.d
+++ b/build/debug/unicode_width/unicode_width.d
@@ -0,0 +1,3 @@
+build/debug/unicode_width/unicode_width.o: \
+ libs/unicode_width/unicode_width.c libs/unicode_width/unicode_width.h
+libs/unicode_width/unicode_width.h:
--- a/build/debug/unicode_width/unicode_width.dwo
+++ b/build/debug/unicode_width/unicode_width.dwo
--- a/build/debug/utils.d
+++ b/build/debug/utils.d
@@ -0,0 +1,4 @@
+build/debug/utils.o: src/utils.cc src/../libs/libgrapheme/grapheme.h \
+ src/../include/utils.h
+src/../libs/libgrapheme/grapheme.h:
+src/../include/utils.h:
--- a/build/debug/utils.dwo
+++ b/build/debug/utils.dwo
--- a/build/release/editor.d
+++ b/build/release/editor.d
@@ -0,0 +1,15 @@
+build/release/editor.o: src/editor.cc src/../libs/libgrapheme/grapheme.h \
+  src/../include/editor.h \
+  src/../include/../libs/tree-sitter/lib/include/tree_sitter/api.h \
+  src/../include/./rope.h src/../include/./ui.h src/../include/./utils.h \
+  src/../include/ts.h src/../include/./editor.h \
+  src/../libs/tree-sitter-ruby/bindings/c/tree-sitter-ruby.h
+src/../libs/libgrapheme/grapheme.h:
+src/../include/editor.h:
+src/../include/../libs/tree-sitter/lib/include/tree_sitter/api.h:
+src/../include/./rope.h:
+src/../include/./ui.h:
+src/../include/./utils.h:
+src/../include/ts.h:
+src/../include/./editor.h:
+src/../libs/tree-sitter-ruby/bindings/c/tree-sitter-ruby.h:
--- a/build/release/input.d
+++ b/build/release/input.d
@@ -0,0 +1,2 @@
+build/release/input.o: src/input.cc src/../include/ui.h
+src/../include/ui.h:
--- a/build/release/main.d
+++ b/build/release/main.d
@@ -0,0 +1,14 @@
+build/release/main.o: src/main.cc src/../include/editor.h \
+  src/../include/../libs/tree-sitter/lib/include/tree_sitter/api.h \
+  src/../include/./rope.h src/../include/./ui.h src/../include/./utils.h \
+  src/../include/ts.h src/../include/./editor.h src/../include/ui.h \
+  src/../libs/tree-sitter/lib/include/tree_sitter/api.h
+src/../include/editor.h:
+src/../include/../libs/tree-sitter/lib/include/tree_sitter/api.h:
+src/../include/./rope.h:
+src/../include/./ui.h:
+src/../include/./utils.h:
+src/../include/ts.h:
+src/../include/./editor.h:
+src/../include/ui.h:
+src/../libs/tree-sitter/lib/include/tree_sitter/api.h:
--- a/build/release/renderer.d
+++ b/build/release/renderer.d
@@ -0,0 +1,6 @@
+build/release/renderer.o: src/renderer.cc \
+  src/../libs/libgrapheme/grapheme.h \
+  src/../libs/unicode_width/unicode_width.h src/../include/ui.h
+src/../libs/libgrapheme/grapheme.h:
+src/../libs/unicode_width/unicode_width.h:
+src/../include/ui.h:
--- a/build/release/rope.d
+++ b/build/release/rope.d
@@ -0,0 +1,2 @@
+build/release/rope.o: src/rope.cc src/../include/rope.h
+src/../include/rope.h:
--- a/build/release/ts.d
+++ b/build/release/ts.d
@@ -0,0 +1,14 @@
+build/release/ts.o: src/ts.cc src/../include/ts.h \
+  src/../include/./editor.h \
+  src/../include/./../libs/tree-sitter/lib/include/tree_sitter/api.h \
+  src/../include/././rope.h src/../include/././ui.h \
+  src/../include/././utils.h src/../include/editor.h \
+  src/../include/rope.h
+src/../include/ts.h:
+src/../include/./editor.h:
+src/../include/./../libs/tree-sitter/lib/include/tree_sitter/api.h:
+src/../include/././rope.h:
+src/../include/././ui.h:
+src/../include/././utils.h:
+src/../include/editor.h:
+src/../include/rope.h:
--- a/build/release/unicode_width/unicode_width.d
+++ b/build/release/unicode_width/unicode_width.d
@@ -0,0 +1,3 @@
+build/release/unicode_width/unicode_width.o: \
+  libs/unicode_width/unicode_width.c libs/unicode_width/unicode_width.h
+libs/unicode_width/unicode_width.h:
--- a/build/release/utils.d
+++ b/build/release/utils.d
@@ -0,0 +1,4 @@
+build/release/utils.o: src/utils.cc src/../libs/libgrapheme/grapheme.h \
+  src/../include/utils.h
+src/../libs/libgrapheme/grapheme.h:
+src/../include/utils.h:
--- a/compile.sh
+++ b/compile.sh
@@ -1,11 +0,0 @@
-#!/usr/bin/env bash
-
-set -euo pipefail
-
-DIR="$(cd -- "$(dirname -- "$0")" && pwd)"
-
-mkdir -p "$DIR/builds"
-
-g++ -O2 -std=c++20 -shared -fPIC -Wall -Wextra \
-  -o "$DIR/builds/C-crib.so" $DIR/src/cpp/*.cpp
-strip "$DIR/builds/C-crib.so"
--- a/crib.rb
+++ b/crib.rb
@@ -1,53 +0,0 @@
-#!/usr/bin/env ruby
-
-require_relative "./src/ruby/mod"
-
-# C.start_screen
-#
-# at_exit do
-#   C.end_screen
-#   puts "bye"
-# end
-#
-#
-# class Tester
-#   @current_row = 0
-#
-#   class << self
-#     def debug_print(text)
-#       text.each_char.with_index do |ch, i|
-#         C.update(@current_row, i, ch, 0xFFFFFE, 0x000001, 0)
-#       end
-#       @current_row += 1
-#     end
-#
-#     def reset
-#       @current_row = 0
-#     end
-#   end
-# end
-#
-# render_thread = Thread.new do
-#   loop do
-#     sleep(1.0/20)
-#     C.render
-#   end
-# end
-#
-# loop do
-#   sleep 0.001
-#   event = C.read_key
-#   break if event[:key_type] == 0 && event[:c] == 'q'.ord
-#   Tester.reset if event[:key_type] == 0 && event[:c] == 'r'.ord
-#   Tester.debug_print(C.get_size.to_s) if event[:key_type] == 0 && event[:c] == 's'.ord
-#   Tester.debug_print(event.to_s)
-# end
-#
-# render_thread.kill
-# render_thread.join
-
-require_relative("./src/ruby/editor.rb")
-
-test = Buffer.new("hello world\nwow")
-
-pp test.render_text(0, 0, 10, 10)
--- a/grammar/ruby.scm
+++ b/grammar/ruby.scm
@@ -0,0 +1,346 @@
+[
+  (method)
+  (singleton_method)
+  (class)
+  (module)
+  (if)
+  (else)
+  (case)
+  (when)
+  (in)
+  (do_block)
+  (singleton_class)
+  (heredoc_content)
+  (lambda)
+] @fold
+
+;; #ffffff #000000 0 0 0 1
+[
+  (identifier)
+  (global_variable)
+] @variable
+
+;; #fbb152 #000000 0 0 0 1
+[
+  "alias"
+  "begin"
+  "do"
+  "end"
+  "ensure"
+  "module"
+  "rescue"
+  "then"
+] @keyword
+
+;; #fbb152 #000000 0 0 0 1
+"class" @keyword.type
+
+
+;; #fbb152 #000000 0 0 0 1
+[
+  "return"
+  "yield"
+] @keyword.return
+
+;; #fbb152 #000000 0 0 0 1
+[
+  "and"
+  "or"
+  "in"
+  "not"
+] @keyword.operator
+
+;; #fbb152 #000000 0 0 0 1
+[
+  "def"
+  "undef"
+] @keyword.function
+
+(method
+  "end" @keyword.function)
+
+
+;; #fbb152 #000000 0 0 0 1
+[
+  "case"
+  "else"
+  "elsif"
+  "if"
+  "unless"
+  "when"
+  "then"
+] @keyword.conditional
+
+(if
+  "end" @keyword.conditional)
+
+;; #fbb152 #000000 0 0 0 1
+[
+  "for"
+  "until"
+  "while"
+  "break"
+  "redo"
+  "retry"
+  "next"
+] @keyword.repeat
+
+;; #ebda8c #000000 0 0 0 1
+(constant) @constant
+
+;; #fbb152 #000000 0 0 0 1
+[
+  "rescue"
+  "ensure"
+] @keyword.exception
+
+;; #aad84c #000000 0 0 0 1
+"defined?" @function
+
+;; #aad84c #000000 0 0 0 1
+(call
+  receiver: (constant)? @type
+  method: [
+    (identifier)
+    (constant)
+  ;; #ff5689 #000000 0 0 0 1
+  ] @function.call)
+
+(alias
+  (identifier) @function)
+
+(setter
+  (identifier) @function)
+
+(method
+  name: [
+    (identifier) @function
+    (constant) @type
+  ])
+
+(singleton_method
+  name: [
+    (identifier) @function
+    (constant) @type
+  ])
+
+(class
+  name: (constant) @type)
+
+(module
+  name: (constant) @type)
+
+(superclass
+  (constant) @type)
+
+;; #ffffff #000000 0 0 0 1
+[
+  (class_variable)
+  (instance_variable)
+] @variable.member
+
+((identifier) @keyword.modifier
+  (#match? @keyword.modifier "^(private|protected|public)$" ))
+
+;; #fbb152 #000000 0 0 0 1
+(program
+  (call
+    (identifier) @keyword.import)
+  (#match? @keyword.import "^(require|require_relative|load)$"))
+
+;; #fbb152 #000000 0 0 0 2
+((identifier) @constant.builtin
+  (#match? @constant.builtin "^(__callee__|__dir__|__id__|__method__|__send__|__ENCODING__|__FILE__|__LINE__)$" ))
+
+;; #aad84c #000000 0 0 0 1
+((identifier) @function.builtin
+  (#match? @function.builtin "^(attr_reader|attr_writer|attr_accessor|module_function)$" ))
+
+((call
+  !receiver
+  method: (identifier) @function.builtin)
+  (#match? @function.builtin "^(include|extend|prepend|refine|using)"))
+
+((identifier) @keyword.exception
+  (#match? @keyword.exception "^(raise|fail|catch|throw)" ))
+
+;; #ffffff #000000 0 0 0 1
+[
+  (self)
+  (super)
+] @variable.builtin
+
+;; #ffffff #000000 0 0 0 1
+(method_parameters
+  (identifier) @variable.parameter)
+
+(lambda_parameters
+  (identifier) @variable.parameter)
+
+(block_parameters
+  (identifier) @variable.parameter)
+
+(splat_parameter
+  (identifier) @variable.parameter)
+
+(hash_splat_parameter
+  (identifier) @variable.parameter)
+
+(optional_parameter
+  (identifier) @variable.parameter)
+
+(destructured_parameter
+  (identifier) @variable.parameter)
+
+(block_parameter
+  (identifier) @variable.parameter)
+
+(keyword_parameter
+  (identifier) @variable.parameter)
+
+;; #aad84c #000000 0 0 0 1
+[
+  (string_content)
+  (heredoc_content)
+  "\""
+  "`"
+] @string
+
+;; #fbb152 #000000 0 0 0 1
+[
+  (heredoc_beginning)
+  (heredoc_end)
+] @label
+
+;; #bd9ae6 #000000 0 0 0 2
+[
+  (bare_symbol)
+  (simple_symbol)
+  (delimited_symbol)
+  (hash_key_symbol)
+] @string.special.symbol
+
+;; #e6a24c #000000 0 0 0 2
+(regex
+  (string_content) @string.regexp)
+
+;; #e6a24c #000000 0 0 0 2
+(escape_sequence) @string.escape
+
+;; #ebda8c #000000 0 0 0 2
+(integer) @number
+
+;; #ebda8c #000000 0 0 0 2
+(float) @number.float
+
+;; #51eeba #000000 0 0 0 1
+(true) @boolean.true
+
+;; #ee513a #000000 0 0 0 1
+(false) @boolean.false
+
+;; #ee8757 #000000 0 0 0 1
+(nil) @constant.nil
+
+;; #AAAAAA #000000 0 1 0 1
+(comment) @comment
+
+(program
+  (comment)+ @comment.documentation
+  (class))
+
+(module
+  (comment)+ @comment.documentation
+  (body_statement
+    (class)))
+
+(class
+  (comment)+ @comment.documentation
+  (body_statement
+    (method)))
+
+(body_statement
+  (comment)+ @comment.documentation
+  (method))
+
+;; #ffffff #000000 0 0 0 1
+[
+  "!"
+  "="
+  ">>"
+  "<<"
+  ">"
+  "<"
+  "**"
+  "*"
+  "/"
+  "%"
+  "+"
+  "-"
+  "&"
+  "|"
+  "^"
+  "%="
+  "+="
+  "-="
+  "*="
+  "/="
+  "=~"
+  "!~"
+  "?"
+  ":"
+] @operator
+
+;; #ffffff #000000 0 1 0 1
+[
+  "=="
+  "==="
+  "<=>"
+  "=>"
+  "->"
+  ">="
+  "<="
+  "||"
+  "||="
+  "&&="
+  "&&"
+  "!="
+  ".."
+  "..."
+] @operator.ligature
+
+;; #bd9ae6 #000000 0 0 0 1
+[
+  ","
+  ";"
+  "."
+  "&."
+  "::"
+] @punctuation.delimiter
+
+;; #bd9ae6 #000000 0 0 0 1
+
+(regex
+  "/" @punctuation.bracket)
+
+(pair
+  ":" @punctuation.delimiter)
+
+[
+  "("
+  ")"
+  "["
+  "]"
+  "{"
+  "}"
+  "%w("
+  "%i("
+] @punctuation.bracket
+
+(block_parameters
+  "|" @punctuation.bracket)
+
+;; #e6a24c #000000 0 0 0 1
+(interpolation
+  "#{" @punctuation.special
+  "}" @punctuation.special)
--- a/include/.keep
+++ b/include/.keep
--- a/include/editor.h
+++ b/include/editor.h
@@ -0,0 +1,111 @@
+#pragma once
+#include "../libs/tree-sitter/lib/include/tree_sitter/api.h"
+#include "./rope.h"
+#include "./ui.h"
+#include "./utils.h"
+#include <cstdint>
+#include <map>
+#include <shared_mutex>
+
+struct Highlight {
+  uint32_t fg;
+  uint32_t bg;
+  uint32_t flags;
+  uint8_t priority;
+};
+
+struct Span {
+  uint32_t start;
+  uint32_t end;
+  Highlight *hl;
+
+  bool operator<(const Span &other) const { return start < other.start; }
+};
+
+struct SpanCursor {
+  const std::vector<Span> &spans;
+  size_t index = 0;
+  std::vector<Span *> active;
+
+  SpanCursor(const std::vector<Span> &s) : spans(s) {}
+  Highlight *get_highlight(uint32_t byte_offset) {
+    for (int i = active.size() - 1; i >= 0; i--)
+      if (active[i]->end <= byte_offset)
+        active.erase(active.begin() + i);
+    while (index < spans.size() && spans[index].start <= byte_offset) {
+      if (spans[index].end > byte_offset)
+        active.push_back(const_cast<Span *>(&spans[index]));
+      index++;
+    }
+    Highlight *best = nullptr;
+    int max_prio = -1;
+    for (auto *s : active) {
+      if (s->hl->priority > max_prio) {
+        max_prio = s->hl->priority;
+        best = s->hl;
+      }
+    }
+    return best;
+  }
+  void sync(uint32_t byte_offset) {
+    active.clear();
+    size_t left = 0, right = spans.size();
+    while (left < right) {
+      size_t mid = (left + right) / 2;
+      if (spans[mid].start <= byte_offset)
+        left = mid + 1;
+      else
+        right = mid;
+    }
+    index = left;
+    while (left > 0) {
+      left--;
+      if (spans[left].end > byte_offset)
+        active.push_back(const_cast<Span *>(&spans[left]));
+      else if (byte_offset - spans[left].end > 1000)
+        break;
+    }
+  }
+};
+
+struct Editor {
+  const char *filename;             // Filename of the editor
+  Knot *root;                       // A rope
+  std::shared_mutex knot_mtx;       // A mutex
+  std::shared_mutex span_mtx;       // A mutex
+  Coord cursor;                     // position of the cursor
+  uint32_t cursor_preffered;        // preffered visual column
+  Coord selection;                  // position of the selection
+  bool selection_active;            // true if there is a selection
+  Coord position;                   // Position of the editor
+  Coord size;                       // Size of the editor
+  Coord scroll;                     // Position of the scroll
+  TSTree *tree;                     // Tree-sitter tree
+  TSParser *parser;                 // Tree-sitter parser
+  TSQuery *query;                   // Tree-sitter query
+  const TSLanguage *language;       // Tree-sitter language
+  Queue<TSInputEdit> edit_queue;    // Tree-sitter edit queue
+  std::vector<Highlight> query_map; // Tree-sitter query map
+  int *folded; // folded lines indexed by line number - cached form of
+               // folded_node
+  std::vector<Span> spans;
+  std::map<uint32_t, bool> folded_node; // maps content hash to fold state
+                                        // - built by tree-sitter
+};
+
+typedef struct TSLoad {
+  Editor *editor;
+  char *prev = nullptr;
+} TSLoad;
+
+Editor *new_editor(const char *filename, Coord position, Coord size);
+void free_editor(Editor *editor);
+void render_editor(Editor *editor);
+void fold(Editor *editor, uint32_t start_line, uint32_t end_line);
+void scroll_up(Editor *editor, uint32_t lines);
+void scroll_down(Editor *editor, uint32_t lines);
+void cursor_up(Editor *editor, uint32_t number);
+void cursor_down(Editor *editor, uint32_t number);
+void cursor_left(Editor *editor, uint32_t number);
+void cursor_right(Editor *editor, uint32_t number);
+void ensure_scroll(Editor *editor);
--- a/include/rope.h
+++ b/include/rope.h
@@ -0,0 +1,157 @@
+#ifndef ROPE_HPP
+#define ROPE_HPP
+
+#include <cstdint>
+#include <vector>
+
+#define MIN_CHUNK_SIZE 64       // 64 Bytes
+#define MAX_CHUNK_SIZE 1024 * 8 // 8192 Bytes (8 KiB)
+#define MAX(a, b) ((a) > (b) ? (a) : (b))
+#define MIN(a, b) ((a) < (b) ? (a) : (b))
+#define DEPTH(n) ((n) ? (n)->depth : 0)
+
+#define PCRE2_CODE_UNIT_WIDTH 8
+#define PCRE_WORKSPACE_SIZE 512
+
+// Rope node definition
+typedef struct Knot {
+  Knot *left;
+  Knot *right;
+  uint8_t depth;
+  uint32_t chunk_size;
+  uint32_t line_count;
+  uint32_t char_count;
+  char data[];
+} Knot;
+
+typedef struct LineIterator {
+  Knot *node;
+  uint8_t top;
+  uint32_t offset;
+  uint32_t line;
+  Knot *stack[64];
+} LineIterator;
+
+typedef struct LeafIterator {
+  Knot *node;
+  uint8_t top;
+  uint32_t offset;
+  Knot *stack[64];
+} LeafIterator;
+
+typedef struct ByteIterator {
+  LeafIterator *it;
+  uint32_t offset_l;
+  uint32_t offset_g;
+  uint32_t char_count;
+  char *data;
+} ByteIterator;
+
+// Rope operations
+
+// Takes lengt of string to be converted
+// to rope and returns a suitable chunk size
+// but rope should work with any positive chunk size
+uint32_t optimal_chunk_size(uint64_t length);
+
+// Takes a string (no need for null termination) and returns a rope
+// len is the length of the string, and chunk size is the size of each chunk
+// load does not free or consume the string.
+// and the str can be freed after load has been run.
+Knot *load(char *str, uint32_t len, uint32_t chunk_size);
+
+// Balances the rope and returns the root
+// n is no longer valid / do not free
+// As rope is balanced by other functions
+// this is not to be used directly
+Knot *balance(Knot *n);
+
+// Concatenates two ropes and returns the joined root
+// Balances the ropes too, if needed
+// left and right are no longer valid / do not free
+// ! left and right should have the same chunk size !
+Knot *concat(Knot *left, Knot *right);
+
+// Used to insert text into the rope
+// node (the rope being inserted into) is no longer valid after call
+// instead use return value as the new node
+// offset is the position of the insertion relative to the start of the rope
+// str is the string to be inserted (no need for null termination)
+// len is the length of the string
+Knot *insert(Knot *node, uint32_t offset, char *str, uint32_t len);
+
+// Similar to insert but for deletion
+// node (the rope being deleted from) is no longer valid after call
+// instead use return value as the new node
+// offset is the position of the deletion relative to the start of the rope
+// len is the length of the deletion
+Knot *erase(Knot *node, uint32_t offset, uint32_t len);
+
+// Used to read a string from the rope
+// root is the rope to be read from
+// offset is the position of the read relative to the start of the rope
+// len is the length of the read
+// returns a null terminated string, should be freed by the caller
+char *read(Knot *root, uint32_t offset, uint32_t len);
+
+// Used to split the rope into left and right ropes
+// node is the rope to be split (it is no longer valid after call / do not free)
+// offset is the position of the split relative to the start of the rope
+// left and right are pointers set to the root of that side of the split
+void split(Knot *node, uint32_t offset, Knot **left, Knot **right);
+
+// Used to convert a byte offset to a line number that contains that byte
+uint32_t byte_to_line(Knot *node, uint32_t offset);
+
+// Used to convert a line number to a byte offset (start of the line)
+// also sets out_len to the length of the line
+uint32_t line_to_byte(Knot *node, uint32_t line, uint32_t *out_len);
+
+// Used to start a line iterator from the start_line number
+// root is the root of the rope
+// returned iterator must be freed after iteration is done
+LineIterator *begin_l_iter(Knot *root, uint32_t start_line);
+
+// Each subsequent call returns the next line as a null terminated string
+// `it` is the iterator returned from begin_l_iter
+// After getting the necessary lines free the iterator (no need to go upto the
+// end) returns null if there are no more lines All return strings `must` be
+// freed by the caller
+char *next_line(LineIterator *it);
+
+// Used to start an iterator over leaf data
+// root is the root of the rope
+// the caller must free the iterator after use
+LeafIterator *begin_k_iter(Knot *root);
+
+// Returns the next leaf data as a null terminated string
+// `it` is the iterator returned from begin_k_iter
+// ! Strings returned must never be freed by the caller !
+// to mutate the string a copy must be made
+char *next_leaf(LeafIterator *it);
+
+// Used to start an iterator over byte data (one byte at a time)
+// Uses leaf iterator internally
+// root is the root of the rope, the caller must free the iterator after use
+ByteIterator *begin_b_iter(Knot *root);
+
+// Returns the next byte from the iterator
+// Returns '\0' if there are no more bytes left
+// `it` is the iterator returned from begin_b_iter
+char next_byte(ByteIterator *it);
+
+// Used to search for a pattern in the rope
+// Pattern is a null terminated string representing a regular expression (DFA
+// compliant) I.e some forms of backtracking etc. are not supported
+// root is the root of the rope to be searched
+// Returns a vector of pairs of start and length offsets (in bytes)
+std::vector<std::pair<size_t, size_t>> search_rope(Knot *root,
+                                                   const char *pattern);
+
+// Helper function to free the rope
+// root is the root of the rope
+// the root is no longer valid after call
+// This must be called only once when the rope is no longer needed
+void free_rope(Knot *root);
+
+#endif // ROPE_HPP
--- a/include/ts.h
+++ b/include/ts.h
@@ -0,0 +1,7 @@
+#pragma once
+#include "./editor.h"
+
+#define HEX(s) (static_cast<uint32_t>(std::stoul(s, nullptr, 16)))
+
+TSQuery *load_query(const char *query_path, Editor *editor);
+void ts_collect_spans(Editor *editor);
--- a/src/headers/header.hpp
+++ b/src/headers/header.hpp
@@ -1,6 +1,8 @@
 #pragma once
+#include <atomic>
 #include <cstdint>
 #include <mutex>
+#include <string.h>
 #include <string>
 #include <sys/ioctl.h>
 #include <termios.h>
@@ -41,6 +43,10 @@
 #define CNTRL_ALT 3
 #define SHIFT 4

+const char VS16_BYTE_A = '\xEF';
+const char VS16_BYTE_B = '\xB8';
+const char VS16_BYTE_C = '\x8F';
+
 enum CellFlags : uint8_t {
  CF_NONE = 0,
  CF_ITALIC = 1 << 0,
@@ -49,12 +55,17 @@ enum CellFlags : uint8_t {
 };

 struct ScreenCell {
-  std::string utf8; // empty => no content
+  std::string utf8 = std::string(""); // empty => no content
  uint32_t fg = 0;
  uint32_t bg = 0;
  uint8_t flags = CF_NONE;
 };

+struct Coord {
+  uint32_t row;
+  uint32_t col;
+};
+
 struct KeyEvent {
  uint8_t key_type;

@@ -71,32 +82,25 @@ struct KeyEvent {
  uint8_t mouse_modifier;
 };

-extern int rows, cols;
+extern uint32_t rows, cols;
 extern std::vector<ScreenCell> screen; // size rows*cols
 extern std::vector<ScreenCell> old_screen;
 extern std::mutex screen_mutex;
+extern std::atomic<bool> running;

-struct coords {
-  int row;
-  int col;
-};
-
-extern "C" {
 void get_terminal_size();
 void die(const char *s);
 void enable_raw_mode();
 void disable_raw_mode();
-void start_screen();
+Coord start_screen();
 void end_screen();
-void update(int row, int col, const char *utf8, uint32_t fg, uint32_t bg,
-            uint8_t flags);
-void set_cursor(int row, int col, bool show_cursor_param);
+void update(uint32_t row, uint32_t col, const char *utf8, uint32_t fg,
+            uint32_t bg, uint8_t flags);
+void set_cursor(int row, int col, int show_cursor_param);
 void render();
-coords get_size();
-
-int real_width(std::string str);
+Coord get_size();

 int read_input(char *buf, size_t buflen);
-KeyEvent read_key_nonblock();
 KeyEvent read_key();
-}
+
+int display_width(const char *str);
--- a/include/utils.h
+++ b/include/utils.h
@@ -0,0 +1,32 @@
+#include <mutex>
+#include <queue>
+#include <string>
+
+template <typename T> struct Queue {
+  std::queue<T> q;
+  std::mutex m;
+
+  void push(T val) {
+    std::lock_guard<std::mutex> lock(m);
+    q.push(val);
+  }
+  bool pop(T &val) {
+    std::lock_guard<std::mutex> lock(m);
+    if (q.empty())
+      return false;
+    val = q.front();
+    q.pop();
+    return true;
+  }
+  bool empty() {
+    std::lock_guard<std::mutex> lock(m);
+    return q.empty();
+  }
+};
+
+uint32_t grapheme_strlen(const char *s);
+uint32_t get_visual_col_from_bytes(const char *line, uint32_t byte_limit);
+uint32_t get_bytes_from_visual_col(const char *line,
+                                   uint32_t target_visual_col);
+void log(const char *fmt, ...);
+std::string get_exe_dir();
--- a/src/.keep
+++ b/src/.keep
--- a/src/editor.cc
+++ b/src/editor.cc
@@ -0,0 +1,508 @@
+extern "C" {
+#include "../libs/libgrapheme/grapheme.h"
+}
+#include "../include/editor.h"
+#include "../include/ts.h"
+#include "../libs/tree-sitter-ruby/bindings/c/tree-sitter-ruby.h"
+#include <cstdint>
+#include <fstream>
+
+char *load_file(const char *path, uint32_t *out_len) {
+  std::ifstream file(path, std::ios::in | std::ios::binary | std::ios::ate);
+  if (!file.is_open())
+    return nullptr;
+  std::streamsize len = file.tellg();
+  if (len < 0 || (std::uint32_t)len > 0xFFFFFFFF)
+    return nullptr;
+  file.seekg(0, std::ios::beg);
+  char *buf = (char *)malloc(static_cast<std::uint32_t>(len));
+  if (!buf)
+    return nullptr;
+  if (file.read(buf, len)) {
+    *out_len = static_cast<uint32_t>(len);
+    return buf;
+  } else {
+    free(buf);
+    return nullptr;
+  }
+}
+
+Editor *new_editor(const char *filename, Coord position, Coord size) {
+  Editor *editor = new Editor();
+  if (!editor)
+    return nullptr;
+  uint32_t len = 0;
+  char *str = load_file(filename, &len);
+  if (!str)
+    return nullptr;
+  editor->filename = filename;
+  editor->position = position;
+  editor->size = size;
+  editor->tree = nullptr;
+  editor->cursor = {0, 0};
+  editor->selection_active = false;
+  editor->selection = {0, 0};
+  editor->scroll = {0, 0};
+  editor->root = load(str, len, optimal_chunk_size(len));
+  editor->folded = (int *)calloc(editor->root->line_count + 2, sizeof(int));
+  std::string query = get_exe_dir() + "/../grammar/ruby.scm";
+  if (!(len > (1024 * 1024))) {
+    editor->parser = ts_parser_new();
+    editor->language = tree_sitter_ruby();
+    ts_parser_set_language(editor->parser, editor->language);
+    editor->query = load_query(query.c_str(), editor);
+  }
+  free(str);
+  return editor;
+}
+
+void free_editor(Editor *editor) {
+  if (editor->folded)
+    free(editor->folded);
+  ts_parser_delete(editor->parser);
+  if (editor->tree)
+    ts_tree_delete(editor->tree);
+  if (editor->query)
+    ts_query_delete(editor->query);
+  free_rope(editor->root);
+  delete editor;
+}
+
+void scroll_up(Editor *editor, uint32_t number) {
+  if (!editor || !editor->root || number == 0)
+    return;
+  uint32_t count = 0;
+  uint32_t visible_lines_checked = 0;
+  int32_t current_check_row = editor->scroll.row;
+  while (visible_lines_checked < number + 1 && current_check_row >= 0) {
+    if (editor->folded[current_check_row] != 1)
+      visible_lines_checked++;
+    count++;
+    current_check_row--;
+  }
+  if (current_check_row < 0)
+    count = editor->scroll.row;
+  LineIterator *it = begin_l_iter(editor->root, editor->scroll.row - count + 1);
+  std::vector<std::pair<uint32_t, uint32_t>> stack;
+  stack.reserve(count);
+  uint32_t lines_iterated = 0;
+  uint32_t start_row = editor->scroll.row - count + 1;
+  while (lines_iterated < count) {
+    char *line_content = next_line(it);
+    uint32_t current_idx = start_row + lines_iterated;
+    int fold_state = editor->folded[current_idx];
+    if (fold_state == 2) {
+      stack.push_back({1, current_idx});
+    } else if (fold_state == 0) {
+      uint32_t len =
+          (line_content != nullptr) ? grapheme_strlen(line_content) : 0;
+      stack.push_back({len, current_idx});
+    }
+    if (line_content)
+      free(line_content);
+    lines_iterated++;
+  }
+  uint32_t ln = 0;
+  uint32_t wrap_limit = editor->size.col;
+  for (int i = stack.size() - 1; i >= 0; i--) {
+    uint32_t len = stack[i].first;
+    uint32_t row_idx = stack[i].second;
+    uint32_t segments =
+        (wrap_limit > 0 && len > 0) ? (len + wrap_limit - 1) / wrap_limit : 1;
+    if (len == 0)
+      segments = 1;
+    for (int seg = (row_idx == editor->scroll.row)
+                       ? editor->scroll.col / wrap_limit
+                       : segments - 1;
+         seg >= 0; seg--) {
+      ln++;
+      if (ln == number + 1) {
+        editor->scroll.row = row_idx;
+        editor->scroll.col = seg * wrap_limit;
+        free(it);
+        return;
+      }
+    }
+  }
+  if (ln < number + 1) {
+    editor->scroll.row = 0;
+    editor->scroll.col = 0;
+  }
+  free(it);
+}
+
+void scroll_down(Editor *editor, uint32_t number) {
+  if (!editor || !editor->root || number == 0)
+    return;
+  LineIterator *it = begin_l_iter(editor->root, editor->scroll.row);
+  uint32_t current_row = editor->scroll.row;
+  uint32_t lines_moved = 0;
+  uint32_t wrap_limit = editor->size.col;
+  if (wrap_limit == 0)
+    wrap_limit = 1;
+  while (lines_moved < number) {
+    char *line_content = next_line(it);
+    if (line_content == nullptr)
+      break;
+    int fold_state = editor->folded[current_row];
+    if (fold_state == 1) {
+      free(line_content);
+      current_row++;
+      continue;
+    }
+    uint32_t segments = 1;
+    if (fold_state == 2) {
+      segments = 1;
+    } else {
+      uint32_t len = grapheme_strlen(line_content);
+      segments = (len > 0) ? (len + wrap_limit - 1) / wrap_limit : 1;
+    }
+    uint32_t start_seg = (current_row == editor->scroll.row)
+                             ? (editor->scroll.col / wrap_limit)
+                             : 0;
+    for (uint32_t seg = start_seg; seg < segments; seg++) {
+      if (current_row == editor->scroll.row && seg == start_seg)
+        continue;
+      lines_moved++;
+      if (lines_moved == number) {
+        editor->scroll.row = current_row;
+        editor->scroll.col = seg * wrap_limit;
+        free(line_content);
+        free(it);
+        return;
+      }
+    }
+    free(line_content);
+    current_row++;
+  }
+  free(it);
+}
+
+void cursor_down(Editor *editor, uint32_t number) {
+  if (!editor || !editor->root || number == 0)
+    return;
+  LineIterator *it = begin_l_iter(editor->root, editor->cursor.row);
+  char *line_content = next_line(it);
+  if (line_content == nullptr)
+    return;
+  uint32_t visual_col =
+      get_visual_col_from_bytes(line_content, editor->cursor.col);
+  do {
+    free(line_content);
+    line_content = next_line(it);
+    editor->cursor.row += 1;
+    if (editor->cursor.row >= editor->root->line_count) {
+      editor->cursor.row = editor->root->line_count - 1;
+      break;
+    };
+    if (editor->folded && editor->folded[editor->cursor.row] != 0)
+      number++;
+  } while (--number > 0);
+  free(it);
+  if (line_content == nullptr)
+    return;
+  editor->cursor.col = get_bytes_from_visual_col(line_content, visual_col);
+  free(line_content);
+}
+
+void cursor_up(Editor *editor, uint32_t number) {
+  if (!editor || !editor->root || number == 0)
+    return;
+  LineIterator *it = begin_l_iter(editor->root, editor->cursor.row);
+  char *line_content = next_line(it);
+  if (!line_content) {
+    free(it);
+    return;
+  }
+  uint32_t visual_col =
+      get_visual_col_from_bytes(line_content, editor->cursor.col);
+  free(line_content);
+  while (number > 0 && editor->cursor.row > 0) {
+    editor->cursor.row--;
+    if (editor->folded && editor->folded[editor->cursor.row] != 0)
+      continue;
+    number--;
+  }
+  free(it);
+  it = begin_l_iter(editor->root, editor->cursor.row);
+  line_content = next_line(it);
+  if (!line_content) {
+    free(it);
+    return;
+  }
+  editor->cursor.col = get_bytes_from_visual_col(line_content, visual_col);
+  free(line_content);
+  free(it);
+}
+
+void cursor_right(Editor *editor, uint32_t number) {
+  if (!editor || !editor->root || number == 0)
+    return;
+  LineIterator *it = begin_l_iter(editor->root, editor->cursor.row);
+  char *line = next_line(it);
+  free(it);
+  if (!line)
+    return;
+  uint32_t line_len = strlen(line);
+  if (line[line_len - 1] == '\n')
+    line[--line_len] = '\0';
+  while (number > 0) {
+    if (editor->cursor.col >= line_len) {
+      free(line);
+      line = nullptr;
+      uint32_t next_row = editor->cursor.row + 1;
+      while (editor->folded && next_row < editor->root->line_count &&
+             editor->folded[next_row] != 0)
+        next_row++;
+      if (next_row >= editor->root->line_count) {
+        editor->cursor.col = line_len;
+        break;
+      }
+      editor->cursor.row = next_row;
+      editor->cursor.col = 0;
+      it = begin_l_iter(editor->root, editor->cursor.row);
+      line = next_line(it);
+      free(it);
+      if (!line)
+        break;
+      line_len = strlen(line);
+      if (line[line_len - 1] == '\n')
+        line[--line_len] = '\0';
+    } else {
+      uint32_t inc = grapheme_next_character_break_utf8(
+          line + editor->cursor.col, line_len - editor->cursor.col);
+      if (inc == 0)
+        break;
+      editor->cursor.col += inc;
+    }
+    number--;
+  }
+  if (line)
+    free(line);
+}
+
+void cursor_left(Editor *editor, uint32_t number) {
+  if (!editor || !editor->root || number == 0)
+    return;
+  LineIterator *it = begin_l_iter(editor->root, editor->cursor.row);
+  char *line = next_line(it);
+  free(it);
+  if (!line)
+    return;
+  uint32_t len = strlen(line);
+  if (line[len - 1] == '\n')
+    line[--len] = '\0';
+  while (number > 0) {
+    if (editor->cursor.col == 0) {
+      free(line);
+      line = nullptr;
+      if (editor->cursor.row == 0)
+        break;
+      int32_t prev_row = editor->cursor.row - 1;
+      while (editor->folded && prev_row >= 0 && editor->folded[prev_row] != 0)
+        prev_row--;
+      if (prev_row < 0)
+        break;
+      editor->cursor.row = prev_row;
+      it = begin_l_iter(editor->root, editor->cursor.row);
+      line = next_line(it);
+      free(it);
+      if (!line)
+        break;
+      uint32_t len = strlen(line);
+      if (line[len - 1] == '\n')
+        line[--len] = '\0';
+      editor->cursor.col = len;
+    } else {
+      uint32_t col = editor->cursor.col;
+      uint32_t new_col = 0;
+      uint32_t visual_col = 0;
+      uint32_t len = strlen(line);
+      while (new_col < col) {
+        uint32_t inc =
+            grapheme_next_character_break_utf8(line + new_col, len - new_col);
+        if (new_col + inc >= col)
+          break;
+        new_col += inc;
+        visual_col++;
+      }
+      editor->cursor.col = new_col;
+    }
+    number--;
+  }
+  if (line)
+    free(line);
+}
+
+void ensure_scroll(Editor *editor) {
+  LineIterator *it = begin_l_iter(editor->root, editor->scroll.row);
+  uint32_t rendered_lines = 0;
+  uint32_t line_index = editor->scroll.row;
+  char *line_content = nullptr;
+  while (rendered_lines <= editor->size.row) {
+    line_content = next_line(it);
+    if (!line_content)
+      break;
+    char *line_content_t = line_content;
+    if (rendered_lines == 0)
+      line_content_t = line_content + editor->scroll.col;
+    uint32_t len = grapheme_strlen(line_content_t);
+    free(line_content);
+    uint32_t wrapped_lines = (len + editor->size.col - 1) / editor->size.col;
+    rendered_lines += wrapped_lines;
+    line_index++;
+  }
+  line_index -= 2;
+  free(it);
+  if (editor->cursor.row >= line_index && line_content)
+    scroll_down(editor, editor->cursor.row - line_index);
+  if (editor->cursor.row < editor->scroll.row)
+    scroll_up(editor, editor->scroll.row - editor->cursor.row);
+}
+
+void fold(Editor *editor, uint32_t start_line, uint32_t end_line) {
+  if (!editor)
+    return;
+  if (!editor->folded) {
+    editor->folded = (int *)calloc(editor->root->line_count + 2, sizeof(int));
+    if (!editor->folded)
+      return;
+  }
+  for (uint32_t i = start_line; i <= end_line && i < editor->size.row; i++)
+    editor->folded[i] = 1;
+  editor->folded[start_line] = 2;
+}
+
+void update_render_fold_marker(uint32_t row, uint32_t cols) {
+  const char *marker = "... folded ...";
+  uint32_t len = strlen(marker);
+  uint32_t i = 0;
+  for (; i < len && i < cols; i++)
+    update(row, i, (char[2]){marker[i], 0}, 0xc6c6c6, 0, 0);
+  for (; i < cols; i++)
+    update(row, i, " ", 0xc6c6c6, 0, 0);
+}
+
+void render_editor(Editor *editor) {
+  uint32_t screen_rows = editor->size.row;
+  uint32_t screen_cols = editor->size.col;
+  uint32_t line_index = editor->scroll.row;
+  SpanCursor span_cursor(editor->spans);
+  std::shared_lock knot_lock(editor->knot_mtx);
+  std::shared_lock span_lock(editor->span_mtx);
+  LineIterator *it = begin_l_iter(editor->root, line_index);
+  if (!it)
+    return;
+  uint32_t rendered_rows = 0;
+  uint32_t global_byte_offset = line_to_byte(editor->root, line_index, nullptr);
+  span_cursor.sync(global_byte_offset);
+  while (rendered_rows < screen_rows) {
+    if (editor->folded && editor->folded[line_index]) {
+      if (editor->folded[line_index] == 2) {
+        update_render_fold_marker(rendered_rows, screen_cols);
+        rendered_rows++;
+      }
+      do {
+        char *line = next_line(it);
+        if (!line)
+          break;
+        global_byte_offset += strlen(line);
+        if (line[strlen(line) - 1] == '\n')
+          global_byte_offset--;
+        global_byte_offset++;
+        free(line);
+        line_index++;
+      } while (line_index < editor->size.row &&
+               editor->folded[line_index] == 1);
+      continue;
+    }
+    char *line = next_line(it);
+    if (!line)
+      break;
+    uint32_t line_len = strlen(line);
+    if (line_len > 0 && line[line_len - 1] == '\n')
+      line_len--;
+    uint32_t current_byte_offset = 0;
+    if (rendered_rows == 0 && editor->scroll.col > 0) {
+      uint32_t skipped_cols = 0;
+      while (skipped_cols < editor->scroll.col &&
+             current_byte_offset < line_len) {
+        uint32_t len = grapheme_next_character_break_utf8(
+            line + current_byte_offset, line_len - current_byte_offset);
+        current_byte_offset += len;
+        skipped_cols++;
+      }
+    }
+    while (current_byte_offset < line_len && rendered_rows < screen_rows) {
+      uint32_t slice_byte_len = 0;
+      uint32_t slice_visual_cols = 0;
+      uint32_t probe_offset = current_byte_offset;
+      while (slice_visual_cols < screen_cols && probe_offset < line_len) {
+        uint32_t len = grapheme_next_character_break_utf8(
+            line + probe_offset, line_len - probe_offset);
+        slice_byte_len += len;
+        probe_offset += len;
+        slice_visual_cols++;
+      }
+      uint32_t col = 0;
+      uint32_t local_render_offset = 0;
+      while (local_render_offset < slice_byte_len) {
+        if (line_index == editor->cursor.row &&
+            editor->cursor.col == (current_byte_offset + local_render_offset))
+          set_cursor(editor->position.row + rendered_rows,
+                     editor->position.col + col, 1);
+        uint32_t absolute_byte_pos =
+            global_byte_offset + current_byte_offset + local_render_offset;
+        Highlight *hl = span_cursor.get_highlight(absolute_byte_pos);
+        uint32_t fg = hl ? hl->fg : 0xFFFFFF;
+        uint32_t bg = hl ? hl->bg : 0;
+        uint8_t fl = hl ? hl->flags : 0;
+        uint32_t cluster_len = grapheme_next_character_break_utf8(
+            line + current_byte_offset + local_render_offset,
+            slice_byte_len - local_render_offset);
+        if (cluster_len == 0)
+          cluster_len = 1;
+        std::string cluster(line + current_byte_offset + local_render_offset,
+                            cluster_len);
+        update(editor->position.row + rendered_rows, editor->position.col + col,
+               cluster.c_str(), fg, bg, fl);
+        local_render_offset += cluster_len;
+        col++;
+      }
+      if (line_index == editor->cursor.row &&
+          editor->cursor.col == (current_byte_offset + slice_byte_len))
+        set_cursor(editor->position.row + rendered_rows,
+                   editor->position.col + col, 1);
+      while (col < screen_cols) {
+        update(editor->position.row + rendered_rows, editor->position.col + col,
+               " ", 0xFFFFFF, 0, 0);
+        col++;
+      }
+      rendered_rows++;
+      current_byte_offset += slice_byte_len;
+    }
+    if (line_len == 0 ||
+        (current_byte_offset >= line_len && rendered_rows == 0)) {
+      if (editor->cursor.row == line_index)
+        set_cursor(editor->position.row + rendered_rows, editor->position.col,
+                   1);
+      uint32_t col = 0;
+      while (col < screen_cols) {
+        update(editor->position.row + rendered_rows, editor->position.col + col,
+               " ", 0xFFFFFF, 0, 0);
+        col++;
+      }
+      rendered_rows++;
+    }
+    global_byte_offset += line_len + 1;
+    line_index++;
+    free(line);
+  }
+  while (rendered_rows < screen_rows) {
+    for (uint32_t col = 0; col < screen_cols; col++)
+      update(editor->position.row + rendered_rows, editor->position.col + col,
+             " ", 0xFFFFFF, 0, 0);
+    rendered_rows++;
+  }
+  free(it);
+}
--- a/src/cpp/input.cpp
+++ b/src/cpp/input.cpp
@@ -1,4 +1,4 @@
-#include "../headers/header.hpp"
+#include "../include/ui.h"

 int read_input(char *buf, size_t buflen) {
  size_t i = 0;
@@ -115,11 +115,9 @@ KeyEvent read_key_nonblock() {
 }

 KeyEvent read_key() {
-  KeyEvent ret;
-  while (1) {
-    ret = read_key_nonblock();
+  while (true) {
+    KeyEvent ret = read_key_nonblock();
    if (ret.key_type != KEY_NONE)
      return ret;
-    usleep(2500);
  }
 }
--- a/src/main.cc
+++ b/src/main.cc
@@ -0,0 +1,199 @@
+#include "../include/editor.h"
+#include "../include/ts.h"
+#include "../include/ui.h"
+#include "../libs/tree-sitter/lib/include/tree_sitter/api.h"
+#include <atomic>
+#include <chrono>
+#include <cstdint>
+#include <iostream>
+#include <sys/ioctl.h>
+#include <thread>
+
+std::atomic<bool> running{true};
+Queue<KeyEvent> event_queue;
+
+std::atomic<uint64_t> render_frames{0};
+std::atomic<uint64_t> worker_frames{0};
+
+auto start_time = std::chrono::high_resolution_clock::now();
+
+void background_worker(Editor *editor) {
+  while (running) {
+    worker_frames++;
+
+    ts_collect_spans(editor);
+
+    std::this_thread::sleep_for(std::chrono::milliseconds(16));
+  }
+}
+
+void input_listener() {
+  while (running) {
+    KeyEvent event = read_key();
+    if (event.key_type == KEY_CHAR && event.c == CTRL('q'))
+      running = false;
+    event_queue.push(event);
+  }
+}
+
+void handle_editor_event(Editor *editor, KeyEvent event) {
+  if (event.key_type == KEY_SPECIAL && event.special_key == KEY_DOWN)
+    cursor_down(editor, 1);
+  if (event.key_type == KEY_SPECIAL && event.special_key == KEY_UP)
+    cursor_up(editor, 1);
+  if (event.key_type == KEY_SPECIAL && event.special_key == KEY_LEFT)
+    cursor_left(editor, 1);
+  if (event.key_type == KEY_SPECIAL && event.special_key == KEY_RIGHT)
+    cursor_right(editor, 1);
+  if (event.key_type == KEY_CHAR &&
+      ((event.c >= 'a' && event.c <= 'z') ||
+       (event.c >= 'A' && event.c <= 'Z') ||
+       (event.c >= '0' && event.c <= '9') || event.c == ' ' || event.c == '!' ||
+       event.c == '@' || event.c == '#' || event.c == '$' || event.c == '%' ||
+       event.c == '^' || event.c == '&' || event.c == '*' || event.c == '(' ||
+       event.c == ')' || event.c == '-' || event.c == '_' || event.c == '=' ||
+       event.c == '+' || event.c == '[' || event.c == ']' || event.c == '{' ||
+       event.c == '}' || event.c == '\\' || event.c == '|' || event.c == ';' ||
+       event.c == ':' || event.c == '\'' || event.c == '"' || event.c == ',' ||
+       event.c == '.' || event.c == '<' || event.c == '>' || event.c == '/' ||
+       event.c == '?' || event.c == '`' || event.c == '~')) {
+    std::shared_lock lock_1(editor->knot_mtx);
+    uint32_t pos = line_to_byte(editor->root, editor->cursor.row, nullptr) +
+                   editor->cursor.col;
+    lock_1.unlock();
+    std::unique_lock lock_2(editor->knot_mtx);
+    editor->root = insert(editor->root, pos, &event.c, 1);
+    lock_2.unlock();
+    if (editor->tree) {
+      TSInputEdit edit = {
+          .start_byte = pos,
+          .old_end_byte = pos,
+          .new_end_byte = pos + 1,
+          .start_point = {editor->cursor.row, editor->cursor.col},
+          .old_end_point = {editor->cursor.row, editor->cursor.col},
+          .new_end_point = {editor->cursor.row, editor->cursor.col + 1},
+      };
+      editor->edit_queue.push(edit);
+    }
+    cursor_right(editor, 1);
+  }
+  if (event.key_type == KEY_CHAR && event.c == '\t') {
+    std::shared_lock lock_1(editor->knot_mtx);
+    uint32_t pos = line_to_byte(editor->root, editor->cursor.row, nullptr) +
+                   editor->cursor.col;
+    lock_1.unlock();
+    std::unique_lock lock_2(editor->knot_mtx);
+    editor->root = insert(editor->root, pos, (char *)"  ", 2);
+    lock_2.unlock();
+    if (editor->tree) {
+      TSInputEdit edit = {
+          .start_byte = pos,
+          .old_end_byte = pos,
+          .new_end_byte = pos + 2,
+          .start_point = {editor->cursor.row, editor->cursor.col},
+          .old_end_point = {editor->cursor.row, editor->cursor.col},
+          .new_end_point = {editor->cursor.row, editor->cursor.col + 2},
+      };
+      editor->edit_queue.push(edit);
+    }
+    cursor_right(editor, 2);
+  }
+  if (event.key_type == KEY_CHAR && (event.c == '\n' || event.c == '\r')) {
+    std::shared_lock lock_1(editor->knot_mtx);
+    uint32_t pos = line_to_byte(editor->root, editor->cursor.row, nullptr) +
+                   editor->cursor.col;
+    lock_1.unlock();
+    std::unique_lock lock_2(editor->knot_mtx);
+    editor->root = insert(editor->root, pos, (char *)"\n", 1);
+    lock_2.unlock();
+    if (editor->tree) {
+      TSInputEdit edit = {
+          .start_byte = pos,
+          .old_end_byte = pos,
+          .new_end_byte = pos + 1,
+          .start_point = {editor->cursor.row, editor->cursor.col},
+          .old_end_point = {editor->cursor.row, editor->cursor.col},
+          .new_end_point = {editor->cursor.row, editor->cursor.col + 1},
+      };
+      editor->edit_queue.push(edit);
+    }
+    cursor_right(editor, 1);
+  }
+  if (event.key_type == KEY_CHAR && event.c == 0x7F) {
+    std::shared_lock lock_1(editor->knot_mtx);
+    uint32_t pos = line_to_byte(editor->root, editor->cursor.row, nullptr) +
+                   editor->cursor.col;
+    TSPoint old_point = {editor->cursor.row, editor->cursor.col};
+    cursor_left(editor, 1);
+    uint32_t start = line_to_byte(editor->root, editor->cursor.row, nullptr) +
+                     editor->cursor.col;
+    lock_1.unlock();
+    std::unique_lock lock_2(editor->knot_mtx);
+    editor->root = erase(editor->root, start, pos - start);
+    lock_2.unlock();
+    if (editor->tree) {
+      TSInputEdit edit = {
+          .start_byte = start,
+          .old_end_byte = pos,
+          .new_end_byte = start,
+          .start_point = {editor->cursor.row, editor->cursor.col},
+          .old_end_point = old_point,
+          .new_end_point = {editor->cursor.row, editor->cursor.col},
+      };
+      editor->edit_queue.push(edit);
+    }
+  }
+  ensure_scroll(editor);
+}
+
+int main(int argc, char *argv[]) {
+  Coord screen = start_screen();
+  const char *filename = (argc > 1) ? argv[1] : "ts.cpp";
+
+  Editor *editor = new_editor(filename, {0, 0}, {screen.row, screen.col});
+  if (!editor) {
+    end_screen();
+    fprintf(stderr, "Failed to load editor\n");
+    return 1;
+  }
+
+  start_time = std::chrono::high_resolution_clock::now();
+
+  std::thread input_thread(input_listener);
+  std::thread work_thread(background_worker, editor);
+
+  while (running) {
+    render_frames++;
+
+    KeyEvent event;
+    while (event_queue.pop(event))
+      handle_editor_event(editor, event);
+
+    render_editor(editor);
+    render();
+
+    std::this_thread::sleep_for(std::chrono::milliseconds(16));
+  }
+
+  input_thread.detach();
+
+  if (work_thread.joinable())
+    work_thread.join();
+
+  auto end_time = std::chrono::high_resolution_clock::now();
+  double seconds = std::chrono::duration<double>(end_time - start_time).count();
+
+  double render_fps = render_frames / seconds;
+  double worker_fps = worker_frames / seconds;
+
+  end_screen();
+
+  std::cout << "\n======= Performance Summary =======\n";
+  std::cout << "Runtime: " << seconds << "s\n";
+  std::cout << "Render loop FPS: " << render_fps << "Hz\n";
+  std::cout << "Worker loop FPS: " << worker_fps << "Hz\n";
+  std::cout << "===================================\n";
+
+  free_editor(editor);
+  return 0;
+}
--- a/src/cpp/renderer.cpp
+++ b/src/cpp/renderer.cpp
@@ -1,26 +1,29 @@
 // includes
-#include "../../libs/libgrapheme/grapheme.h"
-#include "../../libs/unicode_width/unicode_width.h"
-#include "../headers/header.hpp"
+extern "C" {
+#include "../libs/libgrapheme/grapheme.h"
+#include "../libs/unicode_width/unicode_width.h"
+}
+#include "../include/ui.h"

-struct termios orig_termios;
+termios orig_termios;

-int rows, cols;
-bool show_cursor = false;
+uint32_t rows, cols;
+int show_cursor = 0;
 std::vector<ScreenCell> screen;
 std::vector<ScreenCell> old_screen;
 std::mutex screen_mutex;

-int real_width(std::string str) {
-  if (!str.size())
+int display_width(const char *str) {
+  if (!str)
+    return 0;
+  if (!strlen(str))
    return 0;
-  const char *p = str.c_str();
  if (str[0] == '\t')
    return 4;
  unicode_width_state_t state;
  unicode_width_init(&state);
  int width = 0;
-  for (size_t j = 0; j < str.size(); j++) {
+  for (size_t j = 0; j < strlen(str); j++) {
    unsigned char c = str[j];
    if (c < 128) {
      int char_width = unicode_width_process(&state, c);
@@ -28,7 +31,7 @@ int real_width(std::string str) {
        width += char_width;
    } else {
      uint_least32_t cp;
-      size_t bytes = grapheme_decode_utf8(p + j, str.size() - j, &cp);
+      size_t bytes = grapheme_decode_utf8(str + j, strlen(str) - j, &cp);
      if (bytes > 1) {
        int char_width = unicode_width_process(&state, cp);
        if (char_width > 0)
@@ -37,6 +40,7 @@ int real_width(std::string str) {
      }
    }
  }
+
  return width;
 }

@@ -63,6 +67,7 @@ void enable_raw_mode() {
  raw.c_oflag &= ~(OPOST);
  raw.c_cflag |= (CS8);
  raw.c_lflag &= ~(ECHO | ICANON | IEXTEN | ISIG);
+  raw.c_lflag |= ISIG;
  raw.c_cc[VMIN] = 0;
  raw.c_cc[VTIME] = 0;

@@ -74,7 +79,7 @@ void enable_raw_mode() {
 }

 void disable_raw_mode() {
-  std::string os = "\x1b[?1049l\x1b[?25h";
+  std::string os = "\x1b[?1049l\x1b[2 q\x1b[?1002l\x1b[?25h";
  write(STDOUT_FILENO, os.c_str(), os.size());
  if (tcsetattr(STDIN_FILENO, TCSAFLUSH, &orig_termios) == -1) {
    perror("tcsetattr");
@@ -82,30 +87,40 @@ void disable_raw_mode() {
  }
 }

-void start_screen() {
+Coord start_screen() {
  enable_raw_mode();
  get_terminal_size();
  screen.assign(rows * cols, {});     // allocate & zero-init
  old_screen.assign(rows * cols, {}); // allocate & zero-init
+  return {rows, cols};
 }

 void end_screen() { disable_raw_mode(); }

-void update(int row, int col, const char *utf8, uint32_t fg, uint32_t bg,
-            uint8_t flags) {
-  if (row < 0 || row >= rows || col < 0 || col >= cols)
+Coord get_size() { return {rows, cols}; }
+
+void update(uint32_t row, uint32_t col, const char *utf8, uint32_t fg,
+            uint32_t bg, uint8_t flags) {
+  if (row >= rows || col >= cols)
    return;

-  int idx = row * cols + col;
+  uint32_t idx = row * cols + col;
  std::lock_guard<std::mutex> lock(screen_mutex);

-  screen[idx].utf8 = utf8 ? utf8 : ""; // nullptr => empty string
+  screen[idx].utf8 = utf8 ? utf8 : "";
  screen[idx].fg = fg;
  screen[idx].bg = bg;
  screen[idx].flags = flags;
 }

-coords get_size() { return {rows, cols}; }
+bool ends_with(const std::string &string_to_check) {
+  size_t len = string_to_check.size();
+  if (len < 3)
+    return false;
+  return (string_to_check[len - 3] == VS16_BYTE_A) &&
+         (string_to_check[len - 2] == VS16_BYTE_B) &&
+         (string_to_check[len - 1] == VS16_BYTE_C);
+}

 void render() {
  static bool first_render = true;
@@ -114,147 +129,135 @@ void render() {
  bool current_italic = false;
  bool current_bold = false;
  bool current_underline = false;
-
  std::lock_guard<std::mutex> lock(screen_mutex);
-
  std::string out;
-  // reserve a conservative amount to avoid repeated reallocs
  out.reserve(static_cast<size_t>(rows) * static_cast<size_t>(cols) * 4 + 256);
-
-  // save cursor + hide
  out += "\x1b[s\x1b[?25l";
-
  if (first_render) {
    out += "\x1b[2J\x1b[H";
    first_render = false;
  }
-
-  for (int row = 0; row < rows; ++row) {
+  for (uint32_t row = 0; row < rows; ++row) {
    int first_change_col = -1;
    int last_change_col = -1;
-
-    // detect change span in this row
-    for (int col = 0; col < cols; ++col) {
-      int idx = row * cols + col;
+    for (uint32_t col = 0; col < cols; ++col) {
+      uint32_t idx = row * cols + col;
      ScreenCell &old_cell = old_screen[idx];
      ScreenCell &new_cell = screen[idx];
-
-      bool old_empty = old_cell.utf8.empty();
-      bool new_empty = new_cell.utf8.empty();
-
-      bool content_changed =
-          (old_empty && !new_empty) || (!old_empty && new_empty) ||
-          (!old_empty && !new_empty && old_cell.utf8 != new_cell.utf8);
-
+      bool content_changed = old_cell.utf8 != new_cell.utf8;
      bool style_changed =
          (old_cell.fg != new_cell.fg) || (old_cell.bg != new_cell.bg) ||
          ((old_cell.flags & CF_ITALIC) != (new_cell.flags & CF_ITALIC)) ||
          ((old_cell.flags & CF_BOLD) != (new_cell.flags & CF_BOLD)) ||
          ((old_cell.flags & CF_UNDERLINE) != (new_cell.flags & CF_UNDERLINE));
-
      if (content_changed || style_changed) {
        if (first_change_col == -1)
          first_change_col = col;
        last_change_col = col;
      }
    }
-
    if (first_change_col == -1)
      continue;
-
-    // move cursor once to the start of change region
-    char buf[32];
-    int n = snprintf(buf, sizeof(buf), "\x1b[%d;%dH", row + 1,
-                     first_change_col + 1);
-    out.append(buf, n);
-
-    // render changed region
+    char buf[64];
+    snprintf(buf, sizeof(buf), "\x1b[%d;%dH", row + 1, first_change_col + 1);
+    out.append(buf);
    for (int col = first_change_col; col <= last_change_col; ++col) {
      int idx = row * cols + col;
      ScreenCell &old_cell = old_screen[idx];
      ScreenCell &new_cell = screen[idx];
-
-      // foreground change
      if (current_fg != new_cell.fg) {
        if (new_cell.fg) {
          char fb[64];
-          int m = snprintf(
-              fb, sizeof(fb), "\x1b[38;2;%d;%d;%dm", (new_cell.fg >> 16) & 0xFF,
-              (new_cell.fg >> 8) & 0xFF, (new_cell.fg >> 0) & 0xFF);
-          out.append(fb, m);
+          snprintf(fb, sizeof(fb), "\x1b[38;2;%d;%d;%dm",
+                   (new_cell.fg >> 16) & 0xFF, (new_cell.fg >> 8) & 0xFF,
+                   (new_cell.fg >> 0) & 0xFF);
+          out.append(fb);
        } else {
          out += "\x1b[39m";
        }
        current_fg = new_cell.fg;
      }
-
-      // background change
      if (current_bg != new_cell.bg) {
        if (new_cell.bg) {
          char bb[64];
-          int m = snprintf(
-              bb, sizeof(bb), "\x1b[48;2;%d;%d;%dm", (new_cell.bg >> 16) & 0xFF,
-              (new_cell.bg >> 8) & 0xFF, (new_cell.bg >> 0) & 0xFF);
-          out.append(bb, m);
+          snprintf(bb, sizeof(bb), "\x1b[48;2;%d;%d;%dm",
+                   (new_cell.bg >> 16) & 0xFF, (new_cell.bg >> 8) & 0xFF,
+                   (new_cell.bg >> 0) & 0xFF);
+          out.append(bb);
        } else {
          out += "\x1b[49m";
        }
        current_bg = new_cell.bg;
      }
-
-      // italic
      bool italic = (new_cell.flags & CF_ITALIC) != 0;
      if (italic != current_italic) {
        out += italic ? "\x1b[3m" : "\x1b[23m";
        current_italic = italic;
      }
-
-      // bold
      bool bold = (new_cell.flags & CF_BOLD) != 0;
      if (bold != current_bold) {
        out += bold ? "\x1b[1m" : "\x1b[22m";
        current_bold = bold;
      }
-
-      // underline
      bool underline = (new_cell.flags & CF_UNDERLINE) != 0;
      if (underline != current_underline) {
        out += underline ? "\x1b[4m" : "\x1b[24m";
        current_underline = underline;
      }
-
-      // content
      if (!new_cell.utf8.empty()) {
-        if (new_cell.utf8[0] == '\t')
+        if (new_cell.utf8[0] == '\t') {
          out.append("    ");
-        else
+        } else {
+          // HACK: This is a hack to work around the fact that emojis should be
+          //      double width but handling them as so requires a lot of
+          //      calculations for word wrapping so eventually have to do that
+          //      and render them as the 2 wide they should be.
+          if (new_cell.utf8.size() > 1) {
+            if (new_cell.utf8.size() >= 3 && ends_with(new_cell.utf8)) {
+              out.append(new_cell.utf8.substr(0, new_cell.utf8.size() - 3));
+              out.append("\xEF\xB8\x8E");
+            } else {
              out.append(new_cell.utf8);
+              out.append("\xEF\xB8\x8E");
+            }
+          } else {
+            out.append(new_cell.utf8);
+          }
+        }
      } else {
        out.append(1, ' ');
      }
-
-      // copy new -> old (std::string assignment, no strdup/free)
      old_cell.utf8 = new_cell.utf8;
      old_cell.fg = new_cell.fg;
      old_cell.bg = new_cell.bg;
      old_cell.flags = new_cell.flags;
    }
  }
-
-  // final reset + restore cursor + show cursor
  out += "\x1b[0m";
  out += "\x1b[u";
  if (show_cursor)
    out += "\x1b[?25h";
-
-  // single syscall to write the whole frame
-  ssize_t written = write(STDOUT_FILENO, out.data(), out.size());
-  (void)written; // you may check for errors in debug builds
+  const char *ptr = out.data();
+  size_t remaining = out.size();
+  while (remaining > 0) {
+    ssize_t written = write(STDOUT_FILENO, ptr, remaining);
+    if (written == 0) {
+      break;
+    } else if (written == -1) {
+      if (errno == EINTR)
+        continue;
+      die("write failed");
+      break;
+    } else {
+      ptr += written;
+      remaining -= written;
+    }
+  }
 }

-void set_cursor(int row, int col, bool show_cursor_param) {
+void set_cursor(int row, int col, int show_cursor_param) {
  char buf[32];
-  int n = snprintf(buf, sizeof(buf), "\x1b[%d;%dH", row + 1, col + 1);
+  int n = snprintf(buf, sizeof(buf), "\x1b[%d;%dH\x1b[5 q", row + 1, col + 1);
  show_cursor = show_cursor_param;
  write(STDOUT_FILENO, buf, n);
 }
--- a/src/rope.cc
+++ b/src/rope.cc
@@ -0,0 +1,858 @@
+#include "../include/rope.h"
+#include <assert.h>
+#include <cmath>
+#include <cstdint>
+#include <cstdlib>
+#include <cstring>
+#include <pcre2.h>
+#include <stdio.h>
+#include <string.h>
+
+static void update(Knot *n) {
+  if (!n)
+    return;
+  if (!n->depth || n->depth == 0)
+    return;
+  uint32_t left_chars = n->left ? n->left->char_count : 0;
+  uint32_t right_chars = n->right ? n->right->char_count : 0;
+  n->char_count = left_chars + right_chars;
+  uint32_t left_lines = n->left ? n->left->line_count : 0;
+  uint32_t right_lines = n->right ? n->right->line_count : 0;
+  n->line_count = left_lines + right_lines;
+  uint8_t left_depth = n->left ? n->left->depth : 0;
+  uint8_t right_depth = n->right ? n->right->depth : 0;
+  n->depth = MAX(left_depth, right_depth) + 1;
+  n->chunk_size = n->left ? n->left->chunk_size : n->right->chunk_size;
+}
+
+// str is not consumed and \0 is not handled
+// So if str is null terminated then len must be strlen(str)
+// and freed by caller
+Knot *load(char *str, uint32_t len, uint32_t chunk_size) {
+  if (len > (uint32_t)(chunk_size - (chunk_size / 16))) {
+    Knot *left = load(str, len / 2, chunk_size);
+    Knot *right = load(str + len / 2, len - len / 2, chunk_size);
+    Knot *node = (Knot *)malloc(sizeof(Knot));
+    if (!node)
+      return nullptr;
+    node->left = left;
+    node->right = right;
+    node->chunk_size = chunk_size;
+    node->depth = MAX(left->depth, right->depth) + 1;
+    node->char_count = left->char_count + right->char_count;
+    node->line_count = left->line_count + right->line_count;
+    return node;
+  } else {
+    Knot *node = (Knot *)malloc(sizeof(Knot) + chunk_size);
+    if (!node)
+      return nullptr;
+    node->left = nullptr;
+    node->right = nullptr;
+    node->chunk_size = chunk_size;
+    node->depth = 0;
+    node->char_count = len;
+    uint32_t newline_count = 0;
+    for (uint32_t i = 0; i < len; i++) {
+      char c = str[i];
+      node->data[i] = c;
+      if (c == '\n')
+        newline_count++;
+    }
+    node->line_count = newline_count;
+    return node;
+  }
+}
+
+// leaf if consumed and freed (so dont use or free it after)
+// left and right are the new nodes
+static void split_leaf(Knot *leaf, uint32_t k, Knot **left, Knot **right) {
+  Knot *left_node = (Knot *)malloc(sizeof(Knot) + leaf->chunk_size);
+  left_node->left = nullptr;
+  left_node->right = nullptr;
+  left_node->chunk_size = leaf->chunk_size;
+  left_node->depth = 0;
+  left_node->char_count = k;
+  uint32_t newline_count = 0;
+  for (uint32_t i = 0; i < k; i++) {
+    char c = leaf->data[i];
+    left_node->data[i] = c;
+    if (c == '\n')
+      newline_count++;
+  }
+  left_node->line_count = newline_count;
+  uint16_t right_line_count = leaf->line_count - newline_count;
+  *left = left_node;
+  Knot *right_node = (Knot *)malloc(sizeof(Knot) + leaf->chunk_size);
+  right_node->left = nullptr;
+  right_node->right = nullptr;
+  right_node->chunk_size = leaf->chunk_size;
+  right_node->depth = 0;
+  right_node->char_count = leaf->char_count - k;
+  right_node->line_count = right_line_count;
+  for (uint32_t i = k; i < leaf->char_count; i++) {
+    char c = leaf->data[i];
+    right_node->data[i - k] = c;
+  }
+  *right = right_node;
+  free(leaf);
+}
+
+// This makes node nonsensical, so dont use or free it after
+void split(Knot *node, uint32_t offset, Knot **left, Knot **right) {
+  if (!node) {
+    *left = nullptr;
+    *right = nullptr;
+    return;
+  }
+  if (node->depth == 0) {
+    split_leaf(node, offset, left, right);
+    return;
+  }
+  uint32_t left_size = node->left ? node->left->char_count : 0;
+  if (offset < left_size) {
+    Knot *L = nullptr, *R = nullptr;
+    split(node->left, offset, &L, &R);
+    node->left = R;
+    update(node);
+    *right = node;
+    *left = L;
+  } else {
+    uint32_t new_offset = offset - left_size;
+    Knot *L = nullptr, *R = nullptr;
+    split(node->right, new_offset, &L, &R);
+    node->right = L;
+    update(node);
+    *left = node;
+    *right = R;
+  }
+}
+
+static inline int get_balance_factor(Knot *n) {
+  if (!n)
+    return 0;
+  return (int)DEPTH(n->left) - (int)DEPTH(n->right);
+}
+
+static inline Knot *rotate_right(Knot *y) {
+  Knot *x = y->left;
+  Knot *T2 = x->right;
+  x->right = y;
+  y->left = T2;
+  update(y);
+  update(x);
+  return x;
+}
+
+static inline Knot *rotate_left(Knot *x) {
+  Knot *y = x->right;
+  Knot *T2 = y->left;
+  y->left = x;
+  x->right = T2;
+  update(x);
+  update(y);
+  return y;
+}
+
+// Technically n can be used after calling
+// but use return value instead
+Knot *balance(Knot *n) {
+  update(n);
+  int bal = get_balance_factor(n);
+  if (bal > 1) {
+    if (get_balance_factor(n->left) < 0)
+      n->left = rotate_left(n->left);
+    return rotate_right(n);
+  }
+  if (bal < -1) {
+    if (get_balance_factor(n->right) > 0)
+      n->right = rotate_right(n->right);
+    return rotate_left(n);
+  }
+  return n;
+}
+
+// Dont free left or right after calling (only free return value)
+// Assumes both ropes have equal chunk sizes
+Knot *concat(Knot *left, Knot *right) {
+  if (!left)
+    return right;
+  if (!right)
+    return left;
+  if (!left || left->char_count == 0) {
+    if (left)
+      free_rope(left);
+    return right;
+  }
+  if (!right || right->char_count == 0) {
+    if (right)
+      free_rope(right);
+    return left;
+  }
+  if (left->depth == 0 && right->depth == 0) {
+    if (left->char_count + right->char_count <= left->chunk_size) {
+      Knot *node = (Knot *)malloc(sizeof(Knot) + left->chunk_size);
+      node->left = nullptr;
+      node->right = nullptr;
+      node->chunk_size = left->chunk_size;
+      node->depth = 0;
+      node->char_count = left->char_count + right->char_count;
+      node->line_count = left->line_count + right->line_count;
+      memcpy(node->data, left->data, left->char_count);
+      memcpy(node->data + left->char_count, right->data, right->char_count);
+      free(left);
+      free(right);
+      return node;
+    }
+  }
+  uint16_t d_left = left->depth;
+  uint16_t d_right = right->depth;
+  if (d_left > d_right + 1) {
+    left->right = concat(left->right, right);
+    return balance(left);
+  }
+  if (d_right > d_left + 1) {
+    right->left = concat(left, right->left);
+    return balance(right);
+  }
+  Knot *node = (Knot *)malloc(sizeof(Knot));
+  if (!node)
+    return nullptr;
+  node->left = left;
+  node->right = right;
+  node->chunk_size = left->chunk_size;
+  node->depth = MAX(d_left, d_right) + 1;
+  update(node);
+  return node;
+}
+
+// This makes node nonsensical, so dont use or free it after
+// Instead, free the return value or use it in node's place
+Knot *insert(Knot *node, uint32_t offset, char *str, uint32_t len) {
+  if (!node)
+    return nullptr;
+  if (len == 0)
+    return node;
+  if (node->depth == 0 && node->char_count + len <= node->chunk_size) {
+    if (offset < node->char_count)
+      memmove(node->data + offset + len, node->data + offset,
+              node->char_count - offset);
+    memcpy(node->data + offset, str, len);
+    node->char_count += len;
+    for (uint32_t i = 0; i < len; i++)
+      if (str[i] == '\n')
+        node->line_count++;
+    return node;
+  }
+  if (node->depth > 0) {
+    uint32_t left_count = node->left ? node->left->char_count : 0;
+    if (offset < left_count) {
+      Knot *new_left = insert(node->left, offset, str, len);
+      node->left = new_left;
+      update(node);
+      return balance(node);
+    } else {
+      Knot *new_right = insert(node->right, offset - left_count, str, len);
+      node->right = new_right;
+      update(node);
+      return balance(node);
+    }
+  }
+  Knot *left_part = nullptr;
+  Knot *right_part = nullptr;
+  split(node, offset, &left_part, &right_part);
+  Knot *middle_part = load(str, len, node->chunk_size);
+  return concat(concat(left_part, middle_part), right_part);
+}
+
+// This makes node nonsensical, so dont use or free it after
+// Instead, free the return value or use it in node's place
+Knot *erase(Knot *node, uint32_t offset, uint32_t len) {
+  if (!node || len == 0 || offset >= node->char_count)
+    return node;
+  if (offset + len > node->char_count)
+    len = node->char_count - offset;
+  if (node->depth == 0) {
+    uint32_t deleted_newlines = 0;
+    for (uint32_t i = offset; i < offset + len; i++)
+      if (node->data[i] == '\n')
+        deleted_newlines++;
+    node->line_count -= deleted_newlines;
+    if (offset + len < node->char_count)
+      memmove(node->data + offset, node->data + offset + len,
+              node->char_count - (offset + len));
+    node->char_count -= len;
+    return node;
+  }
+  uint32_t left_count = node->left ? node->left->char_count : 0;
+  if (offset + len <= left_count) {
+    node->left = erase(node->left, offset, len);
+  } else if (offset >= left_count) {
+    node->right = erase(node->right, offset - left_count, len);
+  } else {
+    Knot *left = nullptr, *middle = nullptr, *right = nullptr;
+    split(node, offset, &left, &right);
+    split(right, len, &middle, &right);
+    free_rope(middle);
+    return concat(left, right);
+  }
+  update(node);
+  return balance(node);
+}
+
+static void _read_into(Knot *node, uint32_t offset, uint32_t len, char *dest) {
+  if (!node || len == 0)
+    return;
+  if (node->depth == 0) {
+    memcpy(dest, node->data + offset, len);
+    return;
+  }
+  Knot *left = node->left;
+  uint32_t left_count = left ? left->char_count : 0;
+  if (offset < left_count) {
+    uint32_t chunk_len = left_count - offset;
+    if (chunk_len > len)
+      chunk_len = len;
+    _read_into(left, offset, chunk_len, dest);
+    dest += chunk_len;
+    len -= chunk_len;
+    offset = 0;
+  } else {
+    offset -= left_count;
+  }
+  if (len > 0 && node->right)
+    _read_into(node->right, offset, len, dest);
+}
+
+char *read(Knot *root, uint32_t offset, uint32_t len) {
+  if (!root)
+    return nullptr;
+  if (offset >= root->char_count) {
+    char *empty = (char *)malloc(1);
+    if (empty)
+      empty[0] = '\0';
+    return empty;
+  }
+  if (offset + len > root->char_count) {
+    len = root->char_count - offset;
+  }
+  char *buffer = (char *)malloc((len + 1) * sizeof(char));
+  if (!buffer)
+    return nullptr;
+  _read_into(root, offset, len, buffer);
+  buffer[len] = '\0';
+  return buffer;
+}
+
+// Hopefully free the tree only once at the end of its use using the pointer
+// from the last insert or concat or erase call.
+// (or use twice if last call was split - for both left and right).
+void free_rope(Knot *root) {
+  if (!root)
+    return;
+  free_rope(root->left);
+  free_rope(root->right);
+  free(root);
+}
+
+static uint32_t find_nth_newline_offset(Knot *node, uint32_t n) {
+  if (!node || n > node->line_count)
+    return UINT32_MAX;
+  if (node->depth == 0) {
+    uint32_t count = 0;
+    for (uint32_t i = 0; i < node->char_count; i++) {
+      if (node->data[i] == '\n') {
+        if (count == n)
+          return i;
+        count++;
+      }
+    }
+    return UINT32_MAX;
+  }
+  uint32_t left_lines = node->left ? node->left->line_count : 0;
+  if (n < left_lines) {
+    return find_nth_newline_offset(node->left, n);
+  } else {
+    uint32_t right_offset =
+        find_nth_newline_offset(node->right, n - left_lines);
+    if (right_offset == UINT32_MAX)
+      return UINT32_MAX;
+    uint32_t left_chars = node->left ? node->left->char_count : 0;
+    return left_chars + right_offset;
+  }
+}
+
+uint32_t byte_to_line(Knot *node, uint32_t offset) {
+  if (!node)
+    return 0;
+  if (offset >= node->char_count)
+    return node->line_count;
+  if (node->depth == 0) {
+    uint32_t lines_before = 0;
+    uint32_t limit = (offset < node->char_count) ? offset : node->char_count;
+    for (uint32_t i = 0; i < limit; i++)
+      if (node->data[i] == '\n')
+        lines_before++;
+    return lines_before;
+  }
+  uint32_t left_chars = node->left ? node->left->char_count : 0;
+  if (offset < left_chars) {
+    return byte_to_line(node->left, offset);
+  } else {
+    uint32_t left_lines = node->left ? node->left->line_count : 0;
+    return left_lines + byte_to_line(node->right, offset - left_chars);
+  }
+}
+
+uint32_t line_to_byte(Knot *node, uint32_t line, uint32_t *out_len) {
+  if (!node) {
+    if (out_len)
+      *out_len = 0;
+    return 0;
+  }
+  uint32_t start_offset = 0;
+  uint32_t end_offset = 0;
+  if (line == 0) {
+    start_offset = 0;
+  } else {
+    uint32_t prev_newline = find_nth_newline_offset(node, line - 1);
+    if (prev_newline == UINT32_MAX)
+      start_offset = node->char_count;
+    else
+      start_offset = prev_newline + 1;
+  }
+  uint32_t current_newline = find_nth_newline_offset(node, line);
+  if (current_newline == UINT32_MAX)
+    end_offset = node->char_count;
+  else
+    end_offset = current_newline + 1;
+  if (out_len) {
+    if (end_offset > start_offset)
+      *out_len = end_offset - start_offset;
+    else
+      *out_len = 0;
+  }
+  return start_offset;
+}
+
+LineIterator *begin_l_iter(Knot *root, uint32_t start_line) {
+  if (!root)
+    return nullptr;
+  if (start_line > root->line_count)
+    return nullptr;
+  LineIterator *it = (LineIterator *)malloc(sizeof(LineIterator));
+  if (!it)
+    return nullptr;
+  it->top = 0;
+  it->line = start_line;
+  it->node = nullptr;
+  if (start_line == 0) {
+    it->offset = 0;
+    while (root->left) {
+      it->stack[it->top++] = root;
+      root = root->left;
+    }
+    if (!root->left && !root->right)
+      it->node = root;
+    it->stack[it->top++] = root;
+    return it;
+  }
+  Knot *curr = root;
+  uint32_t relative_line = --start_line;
+  it->line = start_line;
+  while (curr) {
+    it->stack[it->top++] = curr;
+    if (!curr->left && !curr->right) {
+      it->node = curr;
+      break;
+    }
+    uint32_t left_lines = (curr->left) ? curr->left->line_count : 0;
+    if (relative_line < left_lines) {
+      curr = curr->left;
+    } else {
+      relative_line -= left_lines;
+      curr = curr->right;
+    }
+  }
+  if (!it->node) {
+    free(it);
+    return nullptr;
+  }
+  it->offset = 0;
+  if (relative_line > 0) {
+    uint32_t found_newlines = 0;
+    uint32_t i = 0;
+    for (i = 0; i < it->node->char_count; i++) {
+      if (it->node->data[i] == '\n') {
+        found_newlines++;
+        if (found_newlines == relative_line) {
+          it->offset = i + 1;
+          break;
+        }
+      }
+    }
+  }
+  free(next_line(it));
+  return it;
+}
+
+static inline void iter_advance_leaf(LineIterator *it) {
+  if (it->top == 0) {
+    it->node = nullptr;
+    return;
+  }
+  Knot *prev = it->stack[--it->top];
+  while (it->top > 0) {
+    Knot *parent = it->stack[it->top - 1];
+    if (parent->left == prev && parent->right) {
+      Knot *curr = parent->right;
+      while (curr) {
+        it->stack[it->top++] = curr;
+        if (!curr->left && !curr->right) {
+          it->node = curr;
+          it->offset = 0;
+          return;
+        }
+        curr = (curr->left) ? curr->left : curr->right;
+      }
+    }
+    prev = it->stack[--it->top];
+  }
+  it->node = nullptr;
+}
+
+char *next_line(LineIterator *it) {
+  if (!it || !it->node)
+    return nullptr;
+  size_t capacity = 128;
+  size_t len = 0;
+  char *buffer = (char *)malloc(capacity);
+  if (!buffer)
+    return nullptr;
+  while (it->node) {
+    if (it->offset >= it->node->char_count) {
+      iter_advance_leaf(it);
+      if (!it->node)
+        break;
+    }
+    char *start = it->node->data + it->offset;
+    char *end = it->node->data + it->node->char_count;
+    char *newline_ptr = (char *)memchr(start, '\n', end - start);
+    size_t chunk_len;
+    bool found_newline = false;
+    if (newline_ptr) {
+      chunk_len = (newline_ptr - start) + 1;
+      found_newline = true;
+    } else {
+      chunk_len = end - start;
+    }
+    if (len + chunk_len + 1 > capacity) {
+      capacity = (capacity * 2) + chunk_len;
+      char *new_buf = (char *)realloc(buffer, capacity);
+      if (!new_buf) {
+        free(buffer);
+        return nullptr;
+      }
+      buffer = new_buf;
+    }
+    memcpy(buffer + len, start, chunk_len);
+    len += chunk_len;
+    it->offset += chunk_len;
+    if (found_newline) {
+      buffer[len] = '\0';
+      it->line++;
+      return buffer;
+    }
+  }
+  if (len > 0) {
+    buffer[len] = '\0';
+    it->line++;
+    return buffer;
+  }
+  free(buffer);
+  return nullptr;
+}
+
+LeafIterator *begin_k_iter(Knot *root) {
+  if (!root)
+    return nullptr;
+  LeafIterator *it = (LeafIterator *)malloc(sizeof(LeafIterator));
+  if (!it)
+    return nullptr;
+  it->top = 0;
+  Knot *curr = root;
+  while (curr) {
+    it->stack[it->top++] = curr;
+    if (!curr->left && !curr->right) {
+      it->node = curr;
+      return it;
+    }
+    curr = curr->left;
+    if (!curr) {
+      curr = it->stack[--it->top]->right;
+      Knot *temp = it->stack[it->top];
+      it->stack[it->top++] = temp;
+      curr = temp->left ? temp->left : temp->right;
+      Knot *parent = it->stack[it->top - 1];
+      curr = parent->left;
+      if (!curr) {
+        curr = parent->right;
+      }
+    }
+  }
+  free(it);
+  return nullptr;
+}
+
+// Caller must never free the returned string
+char *next_leaf(LeafIterator *it) {
+  if (!it || !it->node)
+    return nullptr;
+  char *data_to_return = it->node->data;
+  data_to_return[it->node->char_count] = '\0';
+  Knot *prev_leaf = it->node;
+  Knot *parent = nullptr;
+  while (it->top > 0) {
+    parent = it->stack[--it->top];
+    if (parent->right && parent->right != prev_leaf) {
+      Knot *curr = parent->right;
+      while (curr) {
+        it->stack[it->top++] = curr;
+        if (!curr->left && !curr->right) {
+          it->node = curr;
+          return data_to_return;
+        }
+        curr = curr->left;
+        if (!curr)
+          curr = it->stack[it->top - 1]->right;
+      }
+    }
+    prev_leaf = parent;
+  }
+  it->node = nullptr;
+  return data_to_return;
+}
+
+ByteIterator *begin_b_iter(Knot *root) {
+  ByteIterator *b_it = (ByteIterator *)malloc(sizeof(ByteIterator));
+  LeafIterator *l_it = begin_k_iter(root);
+  b_it->it = l_it;
+  b_it->offset_g = 0;
+  b_it->offset_l = 0;
+  b_it->char_count = 0;
+  b_it->data = nullptr;
+  return b_it;
+}
+
+char next_byte(ByteIterator *it) {
+  if (it->data && it->offset_l < it->char_count) {
+    return it->data[it->offset_l++];
+  } else {
+    it->offset_g += it->offset_l;
+    it->offset_l = 1;
+    char *data = next_leaf(it->it);
+    it->char_count = strlen(data);
+    it->data = data;
+    if (it->data)
+      return *it->data;
+    else
+      return '\0';
+  }
+}
+
+std::vector<std::pair<size_t, size_t>> search_rope(Knot *root,
+                                                   const char *pattern) {
+  std::vector<std::pair<size_t, size_t>> results;
+  int errorcode;
+  PCRE2_SIZE erroffset;
+  pcre2_code *re = pcre2_compile((PCRE2_SPTR)pattern, PCRE2_ZERO_TERMINATED, 0,
+                                 &errorcode, &erroffset, nullptr);
+  if (!re) {
+    fprintf(stderr, "PCRE2 compile error: %d\n", errorcode);
+    return results;
+  }
+  pcre2_match_data *mdata = pcre2_match_data_create(128, nullptr);
+  int workspace[PCRE_WORKSPACE_SIZE];
+  LeafIterator *it = begin_k_iter(root);
+  if (!it) {
+    pcre2_code_free(re);
+    pcre2_match_data_free(mdata);
+    return results;
+  }
+  size_t chunk_abs_offset = 0;
+  size_t saved_match_start = 0;
+  bool match_in_progress = false;
+  int flags = PCRE2_PARTIAL_SOFT;
+  while (1) {
+    const char *chunk_start = next_leaf(it);
+    if (!chunk_start)
+      break;
+    size_t chunk_len = strlen(chunk_start);
+    const char *current_ptr = chunk_start;
+    size_t remaining_len = chunk_len;
+    while (remaining_len > 0) {
+      int rc =
+          pcre2_dfa_match(re, (PCRE2_SPTR)current_ptr, remaining_len, 0, flags,
+                          mdata, nullptr, workspace, PCRE_WORKSPACE_SIZE);
+      if (rc >= 0) {
+        PCRE2_SIZE *ov = pcre2_get_ovector_pointer(mdata);
+        size_t match_start_abs;
+        size_t match_end_abs;
+        if (match_in_progress) {
+          match_start_abs = saved_match_start;
+          match_end_abs =
+              chunk_abs_offset + (current_ptr - chunk_start) + ov[1];
+        } else {
+          match_start_abs =
+              chunk_abs_offset + (current_ptr - chunk_start) + ov[0];
+          match_end_abs =
+              chunk_abs_offset + (current_ptr - chunk_start) + ov[1];
+        }
+        size_t total_len = match_end_abs - match_start_abs;
+        results.push_back(std::make_pair(match_start_abs, total_len));
+        size_t consumed = ov[1];
+        if (consumed == 0)
+          consumed = 1;
+        current_ptr += consumed;
+        if (consumed > remaining_len)
+          remaining_len = 0;
+        else
+          remaining_len -= consumed;
+        match_in_progress = false;
+        flags = PCRE2_PARTIAL_SOFT | PCRE2_NOTBOL;
+        continue;
+      } else if (rc == PCRE2_ERROR_PARTIAL) {
+        PCRE2_SIZE *ov = pcre2_get_ovector_pointer(mdata);
+        if (!match_in_progress) {
+          saved_match_start =
+              chunk_abs_offset + (current_ptr - chunk_start) + ov[0];
+          match_in_progress = true;
+        }
+        flags |= PCRE2_DFA_RESTART;
+        flags |= PCRE2_NOTBOL;
+        break;
+      } else {
+        if (match_in_progress) {
+          match_in_progress = false;
+          flags = PCRE2_PARTIAL_SOFT | PCRE2_NOTBOL;
+          current_ptr++;
+          remaining_len--;
+        } else {
+          break;
+        }
+        // if (rc != PCRE2_ERROR_NOMATCH) {} // handle error
+      }
+    }
+    chunk_abs_offset += chunk_len;
+    if (!match_in_progress)
+      flags = PCRE2_PARTIAL_SOFT | PCRE2_NOTBOL;
+  }
+  pcre2_match_data_free(mdata);
+  pcre2_code_free(re);
+  free(it);
+  return results;
+}
+
+uint32_t optimal_chunk_size(uint64_t length) {
+  if (length <= MIN_CHUNK_SIZE)
+    return MIN_CHUNK_SIZE;
+  double target_exponent = MIN(std::log2((double)MAX_CHUNK_SIZE),
+                               7.0 + (std::log2((double)length) - 10.0) * 0.25);
+  uint32_t final_chunk_size =
+      MAX((uint32_t)MIN_CHUNK_SIZE, (uint32_t)std::pow(2.0, target_exponent));
+  final_chunk_size = MIN(final_chunk_size, (uint32_t)MAX_CHUNK_SIZE);
+  final_chunk_size = 1U << (32 - __builtin_clz(final_chunk_size - 1));
+  return final_chunk_size;
+}
+
+// Basic correctness test & usage example
+/*
+int _main() {
+  char *buffer = (char *)malloc(44 * 4 + 5);
+  strcpy(buffer, "The quick brown fox jumps over the lazy dog.\n\
+The quick brown fox jumps over the lazy dog.\n\
+The quick brown fox jumps over the lazy dog.\n\
+The quick brown fox jumps over the lazy dog.");
+  // This loads all (excluding \0 put in by strcpy)
+  Knot *root = load(buffer, 44 * 4 + 3, optimal_chunk_size(44 * 4 + 3));
+  Knot *left = nullptr, *right = nullptr;
+  // Splits root into left and right (root is no longer valid)
+  split(root, 5, &left, &right);
+  // simple read based on byte offset and length
+  char *s1 = read(left, 0, 100);
+  printf("%s\n:\n", s1);
+  char *s2 = read(right, 0, 100);
+  printf("%s\n;\n", s2);
+  free(s1);
+  free(s2);
+  // Recombines left and right into root (both can
+  // be valid or invalid in optimized cases)
+  // they are to not be used after concat
+  root = concat(left, right);
+  // root should be set to return value from insert always
+  root = insert(root, 5, buffer, 5);
+  free(buffer);
+  char *s3 = read(root, 0, 100);
+  printf("%s\n,\n", s3);
+  // Similar to insert but for erase
+  root = erase(root, 5, 5);
+  char *s4 = read(root, 0, 100);
+  printf("%s\n.\n", s4);
+  free(s3);
+  free(s4);
+  uint32_t byte_offset;
+  uint32_t len;
+  // Byte offset given reltive to how it would
+  // be in a file offset + len includes the \n
+  // at the end of the line (or nothing is EOF)
+  byte_offset = line_to_byte(root, 2, &len);
+  char *s5 = read(root, byte_offset, len);
+  printf("%s\n'\n", s5);
+  free(s5);
+  // returns line number of which line that
+  // byte position would be in.
+  // the ending \n position is included in this
+  uint32_t line = byte_to_line(root, byte_offset + len - 1);
+  printf("%u\n:\n", line);
+  // From second line onwards (0 indexed)
+  LineIterator *it = begin_l_iter(root, 0);
+  char *c = nullptr;
+  while ((c = next_line(it)) != nullptr) {
+    printf("%s :wow:\n", c);
+    free(c);
+  }
+  free(it);
+  printf("\n/\n");
+  // Starts at first byte (to be used for regex search)
+  ByteIterator *it2 = begin_b_iter(root);
+
+  uint32_t saved[40];
+
+  for (int i = 0; i < 40; i++)
+    saved[i] = 0;
+
+  // std::string pattern = "f.x";
+
+  // Inst *program = compile_regex(pattern);
+  //
+  // bool result;
+  // while ((result = next_match(program, it2, saved))) {
+  //   printf("\nRES: %d\n", result);
+  //   for (int i = 0; i < 40; i++)
+  //     printf("%d, ", saved[i]);
+  // }
+
+  // char c2 = ' ';
+  // while ((c2 = next_byte(it2)) != '\0')
+  //   printf("%c :wow!:\n", c2);
+  // free(it2);
+  // search // uses leaf iterator internally // PCRE2 based
+  std::vector<std::pair<size_t, size_t>> matches = search_rope(root, "f.x");
+  for (size_t i = 0; i < matches.size(); i++)
+    printf("\n%lu %lu", matches[i].first, matches[i].second);
+  // A rope needs to be freed only once if last action on the rope is
+  // insert or concat or erase.
+  // for splits we need to free both left and right separately
+  free_rope(root);
+  return 0;
+}
+*/
--- a/src/ruby/editor.rb
+++ b/src/ruby/editor.rb
@@ -1,70 +0,0 @@
-class Buffer
-  # Simple structs for clarity
-  Diagnostic = Struct.new(:x0, :y0, :x1, :y1, :message)
-  Highlight  = Struct.new(:x0, :y0, :x1, :y1, :fg, :bg)
-  VirtualText = Struct.new(:x, :y, :lines)
-  Cursor = Struct.new(:x, :y)
-
-  attr_accessor :text, :cursor, :selection_start,
-                :diagnostics, :highlights, :virtual_texts
-
-  def initialize(initial_text = "")
-    @text = initial_text
-    @cursor = Cursor.new(0, 0)
-    @selection_start = Cursor.new(0, 0)
-    @diagnostics = []
-    @highlights = []
-    @virtual_texts = []
-  end
-
-  # Utility methods
-  def lines
-    @text.split("\n")
-  end
-
-  def line_count
-    lines.size
-  end
-
-  def line(y)
-    lines[y] || ""
-  end
-
-  def insert(x, y, str)
-    current_line = lines[y] || ""
-    before = current_line[0...x] || ""
-    after  = current_line[x..-1] || ""
-    lines_arr = lines
-    lines_arr[y] = before + str + after
-    @text = lines_arr.join("\n")
-  end
-
-  def erase(x0, y0, x1, y1)
-    lines_arr = lines
-    if y0 == y1
-      line = lines_arr[y0] || ""
-      lines_arr[y0] = line[0...x0] + line[x1..-1].to_s
-    else
-      first = lines_arr[y0][0...x0]
-      last  = lines_arr[y1][x1..-1].to_s
-      lines_arr[y0..y1] = [first + last]
-    end
-    @text = lines_arr.join("\n")
-  end
-
-  # Add overlays
-  def add_diagnostic(x0, y0, x1, y1, message)
-    @diagnostics << Diagnostic.new(x0, y0, x1, y1, message)
-  end
-
-  def add_highlight(x0, y0, x1, y1, fg: 0xFFFFFF, bg: 0x000000)
-    @highlights << Highlight.new(x0, y0, x1, y1, fg, bg)
-  end
-
-  def add_virtual_text(x, y, lines)
-    @virtual_texts << VirtualText.new(x, y, lines)
-  end
-
-  def render()
-  end
-end
--- a/src/ruby/mod.rb
+++ b/src/ruby/mod.rb
@@ -1,57 +0,0 @@
-require "ffi"
-require_relative "utils"
-
-module C
-  extend FFI::Library
-  ffi_lib File.join(__dir__, "../../builds/C-crib.so")
-
-  class KeyEvent < FFI::Struct
-    layout :key_type, :uint8,
-           :c, :char,
-           :special_key, :uint8,
-           :special_modifier, :uint8,
-           :mouse_x, :uint8,
-           :mouse_y, :uint8,
-           :mouse_button, :uint8,
-           :mouse_state, :uint8,
-           :mouse_direction, :uint8,
-           :mouse_modifier, :uint8
-
-    def to_s
-      case KEY_TYPE[self[:key_type]]
-      when :char
-        "#<KeyEvent char=#{self[:c].inspect}>"
-      when :special
-        "#<KeyEvent special key=#{SPECIAL_KEY[self[:special_key]]} mod=#{MODIFIER[self[:special_modifier]]}>"
-      when :mouse
-        "#<KeyEvent mouse x=#{self[:mouse_x]} y=#{self[:mouse_y]} " \
-        "btn=#{MOUSE_BUTTON[self[:mouse_button]]} state=#{MOUSE_STATE[self[:mouse_state]]} " \
-        "scroll_dir=#{SCROLL_DIR[self[:mouse_direction]]} mod=#{MODIFIER[self[:mouse_modifier]]}>"
-      else
-        "#<KeyEvent type=#{self[:key_type]} unknown=true>"
-      end
-    end
-  end
-
-  class Coords < FFI::Struct
-    layout :x, :int,
-           :y, :int
-
-    def to_ary
-      [self[:x], self[:y]]
-    end
-
-    def to_s
-      "#<Coords x=#{self[:x]} y=#{self[:y]}>"
-    end
-  end
-
-  attach_function :start_screen, [], :void
-  attach_function :end_screen, [], :void
-  attach_function :update, [:int, :int, :string, :uint32, :uint32, :uint8], :void
-  attach_function :render, [], :void
-  attach_function :set_cursor, [:int, :int, :int], :void
-  attach_function :read_key, [], KeyEvent.by_value
-  attach_function :get_size, [], Coords.by_value
-  attach_function :real_width, [:string], :int
-end
--- a/src/ts.cc
+++ b/src/ts.cc
@@ -0,0 +1,243 @@
+#include "../include/ts.h"
+#include "../include/editor.h"
+#include "../include/rope.h"
+#include <cstdint>
+#include <fstream>
+#include <regex>
+#include <string>
+#include <unordered_map>
+
+static std::unordered_map<std::string, std::regex> regex_cache;
+
+static const std::regex scm_regex(
+    R"((@[A-Za-z0-9_.]+)|(;; \#[0-9a-fA-F]{6} \#[0-9a-fA-F]{6} [01] [01] [01] \d+))");
+
+TSQuery *load_query(const char *query_path, Editor *editor) {
+  const TSLanguage *lang = editor->language;
+  std::ifstream file(query_path, std::ios::in | std::ios::binary);
+  if (!file.is_open())
+    return nullptr;
+  std::string highlight_query((std::istreambuf_iterator<char>(file)),
+                              std::istreambuf_iterator<char>());
+  std::smatch match;
+  std::map<std::string, int> capture_name_cache;
+  Highlight *c_hl = nullptr;
+  int i = 0;
+  int limit = 20;
+  editor->query_map.resize(limit);
+  std::string::const_iterator searchStart(highlight_query.cbegin());
+  while (std::regex_search(searchStart, highlight_query.cend(), match,
+                           scm_regex)) {
+    std::string mct = match.str();
+    if (mct.substr(0, 1) == "@") {
+      std::string capture_name = mct;
+      if (!capture_name_cache.count(capture_name)) {
+        if (c_hl) {
+          if (i >= limit) {
+            limit += 20;
+            editor->query_map.resize(limit);
+          }
+          editor->query_map[i] = *c_hl;
+          delete c_hl;
+          c_hl = nullptr;
+        }
+        capture_name_cache[capture_name] = i;
+        i++;
+      }
+    } else if (mct.substr(0, 2) == ";;") {
+      if (c_hl)
+        delete c_hl;
+      c_hl = new Highlight();
+      c_hl->fg = HEX(mct.substr(4, 6));
+      c_hl->bg = HEX(mct.substr(12, 6));
+      int bold = std::stoi(mct.substr(19, 1));
+      int italic = std::stoi(mct.substr(21, 1));
+      int underline = std::stoi(mct.substr(23, 1));
+      c_hl->priority = std::stoi(mct.substr(25));
+      c_hl->flags = (bold ? CF_BOLD : 0) | (italic ? CF_ITALIC : 0) |
+                    (underline ? CF_UNDERLINE : 0);
+    }
+    searchStart = match.suffix().first;
+  }
+  if (c_hl)
+    delete c_hl;
+  uint32_t error_offset = 0;
+  TSQueryError error_type = (TSQueryError)0;
+  TSQuery *q = ts_query_new(lang, highlight_query.c_str(),
+                            (uint32_t)highlight_query.length(), &error_offset,
+                            &error_type);
+  return q;
+}
+
+static inline const TSNode *find_capture_node(const TSQueryMatch &match,
+                                              uint32_t capture_id) {
+  for (uint32_t i = 0; i < match.capture_count; i++)
+    if (match.captures[i].index == capture_id)
+      return &match.captures[i].node;
+  return nullptr;
+}
+
+static inline std::string node_text(const TSNode &node, Knot *source) {
+  uint32_t start = ts_node_start_byte(node);
+  uint32_t end = ts_node_end_byte(node);
+  char *text = read(source, start, end - start);
+  std::string final = std::string(text, end - start);
+  free(text);
+  return final;
+}
+
+static inline bool ts_predicate(TSQuery *query, const TSQueryMatch &match,
+                                Knot *source) {
+  uint32_t step_count;
+  const TSQueryPredicateStep *steps =
+      ts_query_predicates_for_pattern(query, match.pattern_index, &step_count);
+  if (!steps || step_count != 4)
+    return true;
+  if (source->char_count >= (64 * 1024))
+    return false;
+  std::string command;
+  std::string regex_txt;
+  uint32_t subject_id = 0;
+  for (uint32_t i = 0; i < step_count; i++) {
+    const TSQueryPredicateStep *step = &steps[i];
+    if (step->type == TSQueryPredicateStepTypeDone)
+      break;
+    switch (step->type) {
+    case TSQueryPredicateStepTypeString: {
+      uint32_t length = 0;
+      const char *s =
+          ts_query_string_value_for_id(query, step->value_id, &length);
+      if (i == 0)
+        command.assign(s, length);
+      else
+        regex_txt.assign(s, length);
+      break;
+    }
+    case TSQueryPredicateStepTypeCapture: {
+      subject_id = step->value_id;
+      break;
+    }
+    case TSQueryPredicateStepTypeDone:
+      break;
+    }
+  }
+  const TSNode *node = find_capture_node(match, subject_id);
+  std::string subject = node_text(*node, source);
+  auto it = regex_cache.find(regex_txt);
+  if (it == regex_cache.end())
+    it = regex_cache.emplace(regex_txt, std::regex(regex_txt)).first;
+  const std::regex &re = it->second;
+  if (command == "match?")
+    return std::regex_match(subject, re);
+  else if (command == "not-match?")
+    return !std::regex_match(subject, re);
+  return false;
+}
+
+const char *read_ts(void *payload, uint32_t byte_index, TSPoint,
+                    uint32_t *bytes_read) {
+  if (!running) {
+    *bytes_read = 0;
+    return "";
+  }
+  TSLoad *load = (TSLoad *)payload;
+  Knot *root = load->editor->root;
+  if (load->prev)
+    free(load->prev);
+  if (byte_index >= root->char_count) {
+    *bytes_read = 0;
+    load->prev = nullptr;
+    return "";
+  }
+  uint32_t chunk_size = 4096;
+  uint32_t remaining = root->char_count - byte_index;
+  uint32_t len_to_read = remaining > chunk_size ? chunk_size : remaining;
+  std::shared_lock lock(load->editor->knot_mtx);
+  char *buffer = read(root, byte_index, len_to_read);
+  lock.unlock();
+  load->prev = buffer;
+  *bytes_read = len_to_read;
+  return buffer;
+}
+
+static inline Highlight *safe_get(std::vector<Highlight> &vec, size_t index) {
+  if (index >= vec.size())
+    return nullptr;
+  return &vec[index];
+}
+
+void ts_collect_spans(Editor *editor) {
+  if (!editor->parser || !editor->root || !editor->query)
+    return;
+  TSLoad load = {editor, nullptr};
+  TSInput tsinput = {
+      .payload = &load,
+      .read = read_ts,
+      .encoding = TSInputEncodingUTF8,
+      .decode = nullptr,
+  };
+  TSTree *tree, *copy = nullptr;
+  std::unique_lock lock_0(editor->knot_mtx);
+  if (editor->tree)
+    copy = ts_tree_copy(editor->tree);
+  lock_0.unlock();
+  if (!running)
+    return;
+  std::vector<TSInputEdit> edits;
+  TSInputEdit edit;
+  if (copy) {
+    while (editor->edit_queue.pop(edit)) {
+      edits.push_back(edit);
+      ts_tree_edit(copy, &edits.back());
+    }
+  }
+  tree = ts_parser_parse(editor->parser, copy, tsinput);
+  ts_tree_delete(copy);
+  while (editor->edit_queue.pop(edit)) {
+    edits.push_back(edit);
+    ts_tree_edit(tree, &edits.back());
+  }
+  lock_0.lock();
+  if (editor->tree)
+    ts_tree_delete(editor->tree);
+  editor->tree = tree;
+  copy = ts_tree_copy(tree);
+  lock_0.unlock();
+  std::shared_lock lock_1(editor->span_mtx);
+  TSQueryCursor *cursor = ts_query_cursor_new();
+  ts_query_cursor_exec(cursor, editor->query, ts_tree_root_node(copy));
+  std::vector<Span> new_spans;
+  new_spans.reserve(4096);
+  TSQueryMatch match;
+  while (ts_query_cursor_next_match(cursor, &match)) {
+    if (!running)
+      break;
+    if (!ts_predicate(editor->query, match, editor->root))
+      continue;
+    for (uint32_t i = 0; i < match.capture_count; i++) {
+      if (!running)
+        break;
+      TSQueryCapture cap = match.captures[i];
+      uint32_t start = ts_node_start_byte(cap.node);
+      uint32_t end = ts_node_end_byte(cap.node);
+      Highlight *hl = safe_get(editor->query_map, cap.index);
+      if (hl)
+        new_spans.push_back({start, end, hl});
+    }
+  }
+  if (!running) {
+    ts_tree_delete(copy);
+    ts_query_cursor_delete(cursor);
+    if (load.prev)
+      free(load.prev);
+    return;
+  }
+  lock_1.unlock();
+  std::sort(new_spans.begin(), new_spans.end());
+  std::unique_lock lock_2(editor->span_mtx);
+  editor->spans.swap(new_spans);
+  lock_2.unlock();
+  ts_query_cursor_delete(cursor);
+  if (load.prev)
+    free(load.prev);
+}
--- a/src/utils.cc
+++ b/src/utils.cc
@@ -0,0 +1,87 @@
+extern "C" {
+#include "../libs/libgrapheme/grapheme.h"
+}
+#include "../include/utils.h"
+#include <cstdarg>
+#include <cstdint>
+#include <cstdio>
+#include <limits.h>
+#include <string.h>
+#include <string>
+#include <unistd.h>
+
+std::string get_exe_dir() {
+  char exe_path[PATH_MAX];
+  ssize_t count = readlink("/proc/self/exe", exe_path, PATH_MAX);
+  if (count == -1)
+    return "";
+  exe_path[count] = '\0';
+  std::string path(exe_path);
+  return path.substr(0, path.find_last_of('/'));
+}
+
+uint32_t grapheme_strlen(const char *s) {
+  if (!s)
+    return 0;
+  uint32_t count = 0;
+  const char *p = s;
+  while (*p) {
+    uint32_t next = grapheme_next_character_break_utf8(p, UINT32_MAX);
+    if (!next)
+      next = 1;
+    p += next;
+    count++;
+  }
+  return count;
+}
+
+uint32_t get_visual_col_from_bytes(const char *line, uint32_t byte_limit) {
+  if (!line)
+    return 0;
+  uint32_t visual_col = 0;
+  uint32_t current_byte = 0;
+  uint32_t len = strlen(line);
+  if (len > 0 && line[len - 1] == '\n')
+    len--;
+  while (current_byte < byte_limit && current_byte < len) {
+    uint32_t inc = grapheme_next_character_break_utf8(line + current_byte,
+                                                      len - current_byte);
+    if (current_byte + inc > byte_limit)
+      break;
+    current_byte += inc;
+    visual_col++;
+  }
+  return visual_col;
+}
+
+uint32_t get_bytes_from_visual_col(const char *line,
+                                   uint32_t target_visual_col) {
+  if (!line)
+    return 0;
+  uint32_t visual_col = 0;
+  uint32_t current_byte = 0;
+  uint32_t len = strlen(line);
+  if (len > 0 && line[len - 1] == '\n')
+    len--;
+  while (visual_col < target_visual_col && current_byte < len) {
+    uint32_t inc = grapheme_next_character_break_utf8(line + current_byte,
+                                                      len - current_byte);
+    current_byte += inc;
+    visual_col++;
+  }
+  return current_byte;
+}
+
+void log(const char *fmt, ...) {
+  FILE *fp = fopen("/tmp/log.txt", "a");
+  if (!fp)
+    return;
+
+  va_list args;
+  va_start(args, fmt);
+  vfprintf(fp, fmt, args);
+  va_end(args);
+
+  fputc('\n', fp);
+  fclose(fp);
+}