App.color(Line_number_color)
  love.graphics.print(line_index, State.left-Line_number_width*App.width('m')+10,y)
  if fg == nil then
    initialize_color()
  end

      -- render fragment
      App.color(fg)
      App.screen.print(screen_line, State.left,y)

      -- render colorized text
      local x = State.left
      for frag in screen_line:gmatch('%S*%s*') do
        if fg then
          App.color(fg)
        else
          select_color(frag)
        end
        App.screen.print(frag, x,y)
        x = x+App.width(frag)
      end

  Line_number_width = 3  -- in ems

  love.window.setTitle('TODO')

  love.window.setTitle('Carousel Shell')

  App.screen.width = love.window.fromPixels(App.screen.width)
  App.screen.height = love.window.fromPixels(App.screen.height)

Line_number_color = {r=0.4, g=0.4, b=0.4}

require 'colorize'

-- State transitions while colorizing a single line.
-- Just for comments and strings.
-- Limitation: each fragment gets a uniform color so we can only change color
-- at word boundaries.
Next_state = {
  normal={
    {prefix='--[[', target='block_comment'},  -- only single-line for now
    {prefix='--', target='comment'},
    -- these don't mostly work well until we can change color within words
    -- {prefix='"', target='dstring'},
    -- {prefix="'", target='sstring'},
    {prefix='[[', target='block_string'},  -- only single line for now
  },
  dstring={
    {suffix='"', target='normal'},
  },
  sstring={
    {suffix="'", target='normal'},
  },
  block_string={
    {suffix=']]', target='normal'},
  },
  block_comment={
    {suffix=']]', target='normal'},
  },
  -- comments are a sink
}
Comment_color = {r=0, g=0, b=1}
String_color = {r=0, g=0.5, b=0.5}
Divider_color = {r=0.7, g=0.7, b=0.7}
Colors = {
  normal=Text_color,
  comment=Comment_color,
  sstring=String_color,
  dstring=String_color,
  block_string=String_color,
  block_comment=Comment_color,
}
Current_state = 'normal'
function initialize_color()
--?   print('new line')
  Current_state = 'normal'
end
function select_color(frag)
--?   print('before', '^'..frag..'$', Current_state)
  switch_color_based_on_prefix(frag)
--?   print('using color', Current_state, Colors[Current_state])
  App.color(Colors[Current_state])
  switch_color_based_on_suffix(frag)
--?   print('state after suffix', Current_state)
end
function switch_color_based_on_prefix(frag)
  if Next_state[Current_state] == nil then
    return
  end
  frag = rtrim(frag)
  for _,edge in pairs(Next_state[Current_state]) do
    if edge.prefix and starts_with(frag, edge.prefix) then
      Current_state = edge.target
      break
    end
  end
end
function switch_color_based_on_suffix(frag)
  if Next_state[Current_state] == nil then
    return
  end
  frag = rtrim(frag)
  for _,edge in pairs(Next_state[Current_state]) do
    if edge.suffix and ends_with(frag, edge.suffix) then
      Current_state = edge.target
      break
    end
  end
end

Line_number_padding = 0

on.mouse_release = function(x,y, mouse_button)
	edit.mouse_release(Editor_state, x,y, mouse_button)
end

on.mouse_press = function(x,y, mouse_button)
	edit.mouse_press(Editor_state, x,y, mouse_button)
end

on.key_release = function(key, scancode)
	edit.key_release(Editor_state, key, scancode)
end

on.text_input = function(t)
	edit.text_input(Editor_state, t)
end

on.keychord_press = function(chord, key)
	edit.keychord_press(Editor_state, chord, key)
end

on.draw = function()
	love.graphics.rectangle('line', 100-5-Line_number_padding,100-5, 400+10, 200+10, 5,5)
	edit.draw(Editor_state)
end

on.initialize = function()
	love.graphics.setFont(love.graphics.newFont(20))
	Line_height = math.floor(love.graphics.getFont():getHeight()*1.3)
	Line_number_padding = Line_number_width*App.width('m')
	Editor_state = edit.initialize_state(100, 100, 400, love.graphics.getFont():getHeight(), Line_height)
	Text.redraw_all(Editor_state)
end

Line_height = 0

Editor_state = nil