reconcile all apps with template.tlv

They may take more or less from it (sieve.tlv in particular takes
nothing since call depth doesn't help at all there), but what they take
is in the right order so that you can compare across apps.

8 files changed, 710 insertions, 436 deletions

diff --git a/anagrams.tlv b/anagrams.tlv
index 4678bfa..14f3d21 100644
--- a/anagrams.tlv
+++ b/anagrams.tlv
@@ -62,21 +62,6 @@
     >
     >-- TODO: backport utf-8 support from Lua 5.3
 - __teliva_timestamp: original
-  debugy:
-    >debugy = 5
-- __teliva_timestamp: original
-  dbg:
-    >-- helper for debug by print; overlay debug information towards the right
-    >-- reset debugy every time you refresh screen
-    >function dbg(window, s)
-    >  local oldy = 0
-    >  local oldx = 0
-    >  oldy, oldx = window:getyx()
-    >  window:mvaddstr(debugy, 60, s)
-    >  debugy = debugy+1
-    >  window:mvaddstr(oldy, oldx, '')
-    >end
-- __teliva_timestamp: original
   check_eq:
     >function check_eq(x, expected, msg)
     >  if eq(x, expected) then
@@ -177,8 +162,7 @@
     >  end
     >  return result
     >end
-- __teliva_timestamp:
-    >Mon Feb 21 17:45:04 2022
+- __teliva_timestamp: original
   sort_letters:
     >function sort_letters(s)
     >  tmp = {}
@@ -221,12 +205,6 @@
     >  end
     >end
 - __teliva_timestamp: original
-  Window:
-    >Window = curses.stdscr()
-- __teliva_timestamp: original
-  doc:blurb:
-    >Show all anagrams of a given word
-- __teliva_timestamp: original
   menu:
     >-- To show app-specific hotkeys in the menu bar, add hotkey/command
     >-- arrays of strings to the menu array.
@@ -234,6 +212,12 @@
     >  {'^h', 'backspace'},
     >}
 - __teliva_timestamp: original
+  Window:
+    >Window = curses.stdscr()
+- __teliva_timestamp: original
+  doc:blurb:
+    >Show all anagrams of a given word
+- __teliva_timestamp: original
   word:
     >word = ''
 - __teliva_timestamp: original
diff --git a/commander.tlv b/commander.tlv
index 5416f64..6b80304 100644
--- a/commander.tlv
+++ b/commander.tlv
@@ -62,90 +62,10 @@
     >
     >-- TODO: backport utf-8 support from Lua 5.3
 - __teliva_timestamp: original
-  debugy:
-    >debugy = 5
-- __teliva_timestamp: original
-  dbg:
-    >-- helper for debug by print; overlay debug information towards the right
-    >-- reset debugy every time you refresh screen
-    >function dbg(window, s)
-    >  local oldy = 0
-    >  local oldx = 0
-    >  oldy, oldx = window:getyx()
-    >  window:mvaddstr(debugy, 60, s)
-    >  debugy = debugy+1
-    >  window:mvaddstr(oldy, oldx, '')
-    >end
-- __teliva_timestamp: original
-  check_eq:
-    >function check_eq(x, expected, msg)
-    >  if x == expected then
-    >    Window:addch('.')
-    >  else
-    >    print('F - '..msg)
-    >    print('  expected '..tostring(expected)..' but got '..x)
-    >    teliva_num_test_failures = teliva_num_test_failures + 1
-    >    -- overlay first test failure on editors
-    >    if teliva_first_failure == nil then
-    >      teliva_first_failure = msg
-    >    end
-    >  end
-    >end
-- __teliva_timestamp: original
-  map:
-    >-- only for arrays
-    >function map(l, f)
-    >  result = {}
-    >  for _, x in ipairs(l) do
-    >    table.insert(result, f(x))
-    >  end
-    >  return result
-    >end
-- __teliva_timestamp: original
-  reduce:
-    >-- only for arrays
-    >function reduce(l, f, init)
-    >  result = init
-    >  for _, x in ipairs(l) do
-    >    result = f(result, x)
-    >  end
-    >  return result
-    >end
-- __teliva_timestamp: original
-  filter:
-    >-- only for arrays
-    >function filter(l, f)
-    >  result = {}
-    >  for _, x in ipairs(l) do
-    >    if f(x) then
-    >      table.insert(result, x)
-    >    end
-    >  end
-    >  return result
-    >end
-- __teliva_timestamp: original
-  find_index:
-    >function find_index(arr, x)
-    >  for n, y in ipairs(arr) do
-    >    if x == y then
-    >      return n
-    >    end
-    >  end
-    >end
-- __teliva_timestamp: original
-  trim:
-    >function trim(s)
-    >  return s:gsub('^%s*', ''):gsub('%s*$', '')
-    >end
-- __teliva_timestamp: original
-  split:
-    >function split(s, d)
-    >  result = {}
-    >  for match in (s..d):gmatch("(.-)"..d) do
-    >    table.insert(result, match);
-    >  end
-    >  return result
-    >end
+  menu:
+    >-- To show app-specific hotkeys in the menu bar, add hotkey/command
+    >-- arrays of strings to the menu array.
+    >menu = {}
 - __teliva_timestamp: original
   Window:
     >Window = curses.stdscr()
@@ -162,11 +82,6 @@
     >  window:refresh()
     >end
 - __teliva_timestamp: original
-  menu:
-    >-- To show app-specific hotkeys in the menu bar, add hotkey/command
-    >-- arrays of strings to the menu array.
-    >menu = {}
-- __teliva_timestamp: original
   update:
     >function update(window)
     >  local key = window:getch()
@@ -197,3 +112,6 @@
     >    update(Window)
     >  end
     >end
+- __teliva_timestamp: original
+  doc:blurb:
+    >beginnings of a file browser..
diff --git a/gemini.tlv b/gemini.tlv
index ed0cad7..3a163f0 100644
--- a/gemini.tlv
+++ b/gemini.tlv
@@ -77,21 +77,6 @@
     >  window:mvaddstr(oldy, oldx, '')
     >end
 - __teliva_timestamp: original
-  check_eq:
-    >function check_eq(x, expected, msg)
-    >  if x == expected then
-    >    Window:addch('.')
-    >  else
-    >    print('F - '..msg)
-    >    print('  expected '..tostring(expected)..' but got '..x)
-    >    teliva_num_test_failures = teliva_num_test_failures + 1
-    >    -- overlay first test failure on editors
-    >    if teliva_first_failure == nil then
-    >      teliva_first_failure = msg
-    >    end
-    >  end
-    >end
-- __teliva_timestamp: original
   map:
     >-- only for arrays
     >function map(l, f)
@@ -355,7 +340,7 @@
   init_colors:
     >function init_colors()
     >  for i=0,7 do
-    >    curses.init_pair(i, i, 8)
+    >    curses.init_pair(i, i, -1)
     >  end
     >  curses.init_pair(8, 7, 0)
     >  curses.init_pair(9, 7, 1)
@@ -364,7 +349,7 @@
     >  curses.init_pair(12, 7, 4)
     >  curses.init_pair(13, 7, 5)
     >  curses.init_pair(14, 7, 6)
-    >  curses.init_pair(15, 8, 15)
+    >  curses.init_pair(15, -1, 15)
     >end
 - __teliva_timestamp: original
   main:
diff --git a/life.tlv b/life.tlv
index 0693e7f..78cfa9f 100644
--- a/life.tlv
+++ b/life.tlv
@@ -17,6 +17,370 @@
 # If these constraints are violated, Teliva may unceremoniously crash. Please
 # report bugs at http://akkartik.name/contact
 - __teliva_timestamp: original
+  str_helpers:
+    >-- some string helpers from http://lua-users.org/wiki/StringIndexing
+    >
+    >-- index characters using []
+    >getmetatable('').__index = function(str,i)
+    >  if type(i) == 'number' then
+    >    return string.sub(str,i,i)
+    >  else
+    >    return string[i]
+    >  end
+    >end
+    >
+    >-- ranges using (), selected bytes using {}
+    >getmetatable('').__call = function(str,i,j)
+    >  if type(i)~='table' then
+    >    return string.sub(str,i,j)
+    >  else
+    >    local t={}
+    >    for k,v in ipairs(i) do
+    >      t[k]=string.sub(str,v,v)
+    >    end
+    >    return table.concat(t)
+    >  end
+    >end
+    >
+    >-- iterate over an ordered sequence
+    >function q(x)
+    >  if type(x) == 'string' then
+    >    return x:gmatch('.')
+    >  else
+    >    return ipairs(x)
+    >  end
+    >end
+    >
+    >-- insert within string
+    >function string.insert(str1, str2, pos)
+    >  return str1:sub(1,pos)..str2..str1:sub(pos+1)
+    >end
+    >
+    >function string.remove(s, pos)
+    >  return s:sub(1,pos-1)..s:sub(pos+1)
+    >end
+    >
+    >-- TODO: backport utf-8 support from Lua 5.3
+- __teliva_timestamp: original
+  debugy:
+    >debugy = 5
+- __teliva_timestamp: original
+  dbg:
+    >-- helper for debug by print; overlay debug information towards the right
+    >-- reset debugy every time you refresh screen
+    >function dbg(window, s)
+    >  local oldy = 0
+    >  local oldx = 0
+    >  oldy, oldx = window:getyx()
+    >  window:mvaddstr(debugy, 60, s)
+    >  debugy = debugy+1
+    >  window:mvaddstr(oldy, oldx, '')
+    >end
+- __teliva_timestamp: original
+  check_eq:
+    >function check_eq(x, expected, msg)
+    >  if eq(x, expected) then
+    >    Window:addch('.')
+    >  else
+    >    print('F - '..msg)
+    >    print('  expected '..str(expected)..' but got '..str(x))
+    >    teliva_num_test_failures = teliva_num_test_failures + 1
+    >    -- overlay first test failure on editors
+    >    if teliva_first_failure == nil then
+    >      teliva_first_failure = msg
+    >    end
+    >  end
+    >end
+- __teliva_timestamp: original
+  eq:
+    >function eq(a, b)
+    >  if type(a) ~= type(b) then return false end
+    >  if type(a) == 'table' then
+    >    if #a ~= #b then return false end
+    >    for k, v in pairs(a) do
+    >      if b[k] ~= v then
+    >        return false
+    >      end
+    >      return true
+    >    end
+    >  end
+    >  return a == b
+    >end
+- __teliva_timestamp: original
+  str:
+    >-- smarter tostring
+    >-- slow; used only for debugging
+    >function str(x)
+    >  if type(x) == 'table' then
+    >    local result = ''
+    >    result = result..#x..'{'
+    >    for k, v in pairs(x) do
+    >      result = result..str(k)..'='..str(v)..', '
+    >    end
+    >    result = result..'}'
+    >    return result
+    >  end
+    >  return tostring(x)
+    >end
+- __teliva_timestamp: original
+  map:
+    >-- only for arrays
+    >function map(l, f)
+    >  result = {}
+    >  for _, x in ipairs(l) do
+    >    table.insert(result, f(x))
+    >  end
+    >  return result
+    >end
+- __teliva_timestamp: original
+  reduce:
+    >-- only for arrays
+    >function reduce(l, f, init)
+    >  result = init
+    >  for _, x in ipairs(l) do
+    >    result = f(result, x)
+    >  end
+    >  return result
+    >end
+- __teliva_timestamp: original
+  filter:
+    >-- only for arrays
+    >function filter(l, f)
+    >  result = {}
+    >  for _, x in ipairs(l) do
+    >    if f(x) then
+    >      table.insert(result, x)
+    >    end
+    >  end
+    >  return result
+    >end
+- __teliva_timestamp: original
+  find_index:
+    >function find_index(arr, x)
+    >  for n, y in ipairs(arr) do
+    >    if x == y then
+    >      return n
+    >    end
+    >  end
+    >end
+- __teliva_timestamp: original
+  trim:
+    >function trim(s)
+    >  return s:gsub('^%s*', ''):gsub('%s*$', '')
+    >end
+- __teliva_timestamp: original
+  split:
+    >function split(s, d)
+    >  result = {}
+    >  for match in (s..d):gmatch("(.-)"..d) do
+    >    table.insert(result, match);
+    >  end
+    >  return result
+    >end
+- __teliva_timestamp:
+    >Mon Feb 21 17:45:04 2022
+  sort_letters:
+    >function sort_letters(s)
+    >  tmp = {}
+    >  for i=1,#s do
+    >    table.insert(tmp, s[i])
+    >  end
+    >  table.sort(tmp)
+    >  local result = ''
+    >  for _, c in pairs(tmp) do
+    >    result = result..c
+    >  end
+    >  return result
+    >end
+    >
+    >function test_sort_letters(s)
+    >  check_eq(sort_letters(''), '', 'test_sort_letters: empty')
+    >  check_eq(sort_letters('ba'), 'ab', 'test_sort_letters: non-empty')
+    >  check_eq(sort_letters('abba'), 'aabb', 'test_sort_letters: duplicates')
+    >end
+- __teliva_timestamp: original
+  count_letters:
+    >function count_letters(s)
+    >  local result = {}
+    >  for i=1,string.len(s) do
+    >    local c = s[i]
+    >    if result[c] == nil then
+    >      result[c] = 1
+    >    else
+    >      result[c] = result[c] + 1
+    >    end
+    >  end
+    >  return result
+    >end
+- __teliva_timestamp: original
+  append:
+    >-- concatenate list 'elems' into 'l', modifying 'l' in the process
+    >function append(l, elems)
+    >  for i=1,#elems do
+    >    l[#l+1] = elems[i]
+    >  end
+    >end
+- __teliva_timestamp: original
+  menu:
+    >-- To show app-specific hotkeys in the menu bar, add hotkey/command
+    >-- arrays of strings to the menu array.
+    >menu = {}
+- __teliva_timestamp: original
+  window:
+    >-- constructor for fake screen and window
+    >-- call it like this:
+    >--   local w = window{
+    >--     kbd=kbd('abc'),
+    >--     scr=scr{h=5, w=4},
+    >--   }
+    >-- eventually it'll do everything a real ncurses window can
+    >function window(h)
+    >  h.__index = h
+    >  setmetatable(h, h)
+    >  h.__index = function(table, key)
+    >    return rawget(h, key)
+    >  end
+    >  h.getch = function(self)
+    >    return table.remove(h.kbd, 1)
+    >  end
+    >  h.addch = function(self, c)
+    >    local scr = self.scr
+    >    if scr.cursy <= scr.h then
+    >      scr[scr.cursy][scr.cursx] = c
+    >      scr.cursx = scr.cursx+1
+    >      if scr.cursx > scr.w then
+    >        scr.cursy = scr.cursy+1
+    >        scr.cursx = 1
+    >      end
+    >    end
+    >  end
+    >  h.addstr = function(self, s)
+    >    for i=1,string.len(s) do
+    >      self:addch(s[i])
+    >    end
+    >  end
+    >  h.mvaddch = function(self, y, x, c)
+    >    self.scr.cursy = y
+    >    self.scr.cursx = x
+    >    self.addch(c)
+    >  end
+    >  h.mvaddstr = function(self, y, x, s)
+    >    self.scr.cursy = y
+    >    self.scr.cursx = x
+    >    self:addstr(s)
+    >  end
+    >  return h
+    >end
+- __teliva_timestamp: original
+  kbd:
+    >function kbd(keys)
+    >  local result = {}
+    >  for i=1,string.len(keys) do
+    >    table.insert(result, keys[i])
+    >  end
+    >  return result
+    >end
+- __teliva_timestamp: original
+  scr:
+    >function scr(props)
+    >  props.cursx = 1
+    >  props.cursy = 1
+    >  for y=1,props.h do
+    >    props[y] = {}
+    >    for x=1,props.w do
+    >      props[y][x] = ' '
+    >    end
+    >  end
+    >  return props
+    >end
+- __teliva_timestamp:
+    >Thu Mar  3 22:04:15 2022
+  check_screen:
+    >function check_screen(window, contents, message)
+    >  local x, y = 1, 1
+    >  for i=1,string.len(contents) do
+    >    check_eq(contents[i], window.scr[y][x], message..'/'..y..','..x)
+    >    x = x+1
+    >    if x > window.scr.w then
+    >      y = y+1
+    >      x = 1
+    >    end
+    >  end
+    >end
+    >
+    >-- putting it all together, an example test of both keyboard and screen
+    >function test_check_screen()
+    >  local lines = {
+    >    c='123',
+    >    d='234',
+    >    a='345',
+    >    b='456',
+    >  }
+    >  local w = window{
+    >    kbd=kbd('abc'),
+    >    scr=scr{h=3, w=5},
+    >  }
+    >  local y = 1
+    >  while true do
+    >    local c = w:getch()
+    >    if c == nil then break end
+    >    w:mvaddstr(y, 1, lines[c])
+    >    y = y+1
+    >  end
+    >  check_screen(w, '345  '..
+    >                  '456  '..
+    >                  '123  ',
+    >              'test_check_screen')
+    >end
+- __teliva_timestamp: original
+  start_reading:
+    >-- primitive for reading files from a file system (or, later, network)
+    >-- returns a channel or nil on error
+    >-- read lines from the channel using :recv()
+    >-- recv() on the channel will indicate end of file.
+    >function start_reading(fs, filename)
+    >  local result = task.Channel:new()
+    >  local infile = io.open(filename)
+    >  if infile == nil then return nil end
+    >  task.spawn(reading_task, infile, result)
+    >  return result
+    >end
+    >
+    >function reading_task(infile, chanout)
+    >  for line in infile:lines() do
+    >    chanout:send(line)
+    >  end
+    >  chanout:send(nil)  -- eof
+    >end
+- __teliva_timestamp: original
+  start_writing:
+    >-- primitive for writing files to a file system (or, later, network)
+    >-- returns a channel or nil on error
+    >-- write to the channel using :send()
+    >-- indicate you're done writing by calling :close()
+    >-- file will not be externally visible until :close()
+    >function start_writing(fs, filename)
+    >  local result = task.Channel:new()
+    >  local initial_filename = os.tmpname()
+    >  local outfile = io.open(initial_filename, 'w')
+    >  if outfile == nil then return nil end
+    >  result.close = function()
+    >    result:send(nil)  -- end of file
+    >    outfile:close()
+    >    os.rename(initial_filename, filename)
+    >  end
+    >  task.spawn(writing_task, outfile, result)
+    >  return result
+    >end
+    >
+    >function writing_task(outfile, chanin)
+    >  while true do
+    >    local line = chanin:recv()
+    >    if line == nil then break end  -- end of file
+    >    outfile:write(line)
+    >  end
+    >end
+- __teliva_timestamp: original
   grid:
     >-- main data structure
     >grid = {}
diff --git a/sieve.tlv b/sieve.tlv
index 92c086a..9677af4 100644
--- a/sieve.tlv
+++ b/sieve.tlv
@@ -17,248 +17,13 @@
 # If these constraints are violated, Teliva may unceremoniously crash. Please
 # report bugs at http://akkartik.name/contact
 - __teliva_timestamp: original
-  str_helpers:
-    >-- some string helpers from http://lua-users.org/wiki/StringIndexing
-    >
-    >-- index characters using []
-    >getmetatable('').__index = function(str,i)
-    >  if type(i) == 'number' then
-    >    return string.sub(str,i,i)
-    >  else
-    >    return string[i]
-    >  end
-    >end
-    >
-    >-- ranges using (), selected bytes using {}
-    >getmetatable('').__call = function(str,i,j)
-    >  if type(i)~='table' then
-    >    return string.sub(str,i,j)
-    >  else
-    >    local t={}
-    >    for k,v in ipairs(i) do
-    >      t[k]=string.sub(str,v,v)
-    >    end
-    >    return table.concat(t)
-    >  end
-    >end
-    >
-    >-- iterate over an ordered sequence
-    >function q(x)
-    >  if type(x) == 'string' then
-    >    return x:gmatch('.')
-    >  else
-    >    return ipairs(x)
-    >  end
-    >end
-    >
-    >-- insert within string
-    >function string.insert(str1, str2, pos)
-    >  return str1:sub(1,pos)..str2..str1:sub(pos+1)
-    >end
-    >
-    >function string.remove(s, pos)
-    >  return s:sub(1,pos-1)..s:sub(pos+1)
-    >end
-    >
-    >-- TODO: backport utf-8 support from Lua 5.3
-- __teliva_timestamp: original
-  debugy:
-    >debugy = 5
-- __teliva_timestamp: original
-  dbg:
-    >-- helper for debug by print; overlay debug information towards the right
-    >-- reset debugy every time you refresh screen
-    >function dbg(window, s)
-    >  local oldy = 0
-    >  local oldx = 0
-    >  oldy, oldx = window:getyx()
-    >  window:mvaddstr(debugy, 60, s)
-    >  debugy = debugy+1
-    >  window:mvaddstr(oldy, oldx, '')
-    >end
-- __teliva_timestamp: original
-  check_eq:
-    >function check_eq(x, expected, msg)
-    >  if eq(x, expected) then
-    >    Window:addch('.')
-    >  else
-    >    print('F - '..msg)
-    >    print('  expected '..str(expected)..' but got '..str(x))
-    >    teliva_num_test_failures = teliva_num_test_failures + 1
-    >    -- overlay first test failure on editors
-    >    if teliva_first_failure == nil then
-    >      teliva_first_failure = msg
-    >    end
-    >  end
-    >end
-- __teliva_timestamp: original
-  eq:
-    >function eq(a, b)
-    >  if type(a) ~= type(b) then return false end
-    >  if type(a) == 'table' then
-    >    if #a ~= #b then return false end
-    >    for k, v in pairs(a) do
-    >      if b[k] ~= v then
-    >        return false
-    >      end
-    >      return true
-    >    end
-    >  end
-    >  return a == b
-    >end
-- __teliva_timestamp: original
-  str:
-    >-- smarter tostring
-    >-- slow; used only for debugging
-    >function str(x)
-    >  if type(x) == 'table' then
-    >    local result = ''
-    >    result = result..#x..'{'
-    >    for k, v in pairs(x) do
-    >      result = result..str(k)..'='..str(v)..', '
-    >    end
-    >    result = result..'}'
-    >    return result
-    >  end
-    >  return tostring(x)
-    >end
-- __teliva_timestamp: original
-  map:
-    >-- only for arrays
-    >function map(l, f)
-    >  result = {}
-    >  for _, x in ipairs(l) do
-    >    table.insert(result, f(x))
-    >  end
-    >  return result
-    >end
-- __teliva_timestamp: original
-  reduce:
-    >-- only for arrays
-    >function reduce(l, f, init)
-    >  result = init
-    >  for _, x in ipairs(l) do
-    >    result = f(result, x)
-    >  end
-    >  return result
-    >end
-- __teliva_timestamp: original
-  filter:
-    >-- only for arrays
-    >function filter(l, f)
-    >  result = {}
-    >  for _, x in ipairs(l) do
-    >    if f(x) then
-    >      table.insert(result, x)
-    >    end
-    >  end
-    >  return result
-    >end
-- __teliva_timestamp: original
-  find_index:
-    >function find_index(arr, x)
-    >  for n, y in ipairs(arr) do
-    >    if x == y then
-    >      return n
-    >    end
-    >  end
-    >end
-- __teliva_timestamp: original
-  trim:
-    >function trim(s)
-    >  return s:gsub('^%s*', ''):gsub('%s*$', '')
-    >end
-- __teliva_timestamp: original
-  split:
-    >function split(s, d)
-    >  result = {}
-    >  for match in (s..d):gmatch("(.-)"..d) do
-    >    table.insert(result, match);
-    >  end
-    >  return result
-    >end
-- __teliva_timestamp:
-    >Mon Feb 21 17:45:04 2022
-  sort_string:
-    >function sort_string(s)
-    >  tmp = {}
-    >  for i=1,#s do
-    >    table.insert(tmp, s[i])
-    >  end
-    >  table.sort(tmp)
-    >  local result = ''
-    >  for _, c in pairs(tmp) do
-    >    result = result..c
-    >  end
-    >  return result
-    >end
-    >
-    >function test_sort_string(s)
-    >  check_eq(sort_string(''), '', 'test_sort_string: empty')
-    >  check_eq(sort_string('ba'), 'ab', 'test_sort_string: non-empty')
-    >  check_eq(sort_string('abba'), 'aabb', 'test_sort_string: duplicates')
-    >end
-- __teliva_timestamp: original
-  append:
-    >-- concatenate list 'elems' into 'l', modifying 'l' in the process
-    >function append(l, elems)
-    >  for i=1,#elems do
-    >    l[#l+1] = elems[i]
-    >  end
-    >end
-- __teliva_timestamp: original
-  Window:
-    >Window = curses.stdscr()
-- __teliva_timestamp: original
-  render:
-    >function render(window)
-    >  window:clear()
-    >  -- draw stuff to screen here
-    >  window:attron(curses.A_BOLD)
-    >  window:mvaddstr(1, 5, "example app")
-    >  window:attrset(curses.A_NORMAL)
-    >  for i=0,15 do
-    >    window:attrset(curses.color_pair(i))
-    >    window:mvaddstr(3+i, 5, "========================")
-    >  end
-    >  window:refresh()
-    >end
-- __teliva_timestamp: original
   menu:
     >-- To show app-specific hotkeys in the menu bar, add hotkey/command
     >-- arrays of strings to the menu array.
     >menu = {}
 - __teliva_timestamp: original
-  update:
-    >function update(window)
-    >  local key = window:getch()
-    >  -- process key here
-    >end
-- __teliva_timestamp: original
-  init_colors:
-    >function init_colors()
-    >  for i=0,7 do
-    >    curses.init_pair(i, i, -1)
-    >  end
-    >  curses.init_pair(8, 7, 0)
-    >  curses.init_pair(9, 7, 1)
-    >  curses.init_pair(10, 7, 2)
-    >  curses.init_pair(11, 7, 3)
-    >  curses.init_pair(12, 7, 4)
-    >  curses.init_pair(13, 7, 5)
-    >  curses.init_pair(14, 7, 6)
-    >  curses.init_pair(15, -1, 15)
-    >end
-- __teliva_timestamp: original
-  main:
-    >function main()
-    >  init_colors()
-    >
-    >  while true do
-    >    render(Window)
-    >    update(Window)
-    >  end
-    >end
+  Window:
+    >Window = curses.stdscr()
 - __teliva_timestamp: original
   doc:blurb:
     >To show a brief description of the app on the 'big picture' screen, put the text in a special buffer called 'doc:blurb'.
diff --git a/template.tlv b/template.tlv
index 63210d1..4ec78b2 100644
--- a/template.tlv
+++ b/template.tlv
@@ -177,8 +177,7 @@
     >  end
     >  return result
     >end
-- __teliva_timestamp:
-    >Mon Feb 21 17:45:04 2022
+- __teliva_timestamp: original
   sort_letters:
     >function sort_letters(s)
     >  tmp = {}
@@ -221,63 +220,13 @@
     >  end
     >end
 - __teliva_timestamp: original
-  Window:
-    >Window = curses.stdscr()
-- __teliva_timestamp: original
-  render:
-    >function render(window)
-    >  window:clear()
-    >  -- draw stuff to screen here
-    >  window:attron(curses.A_BOLD)
-    >  window:mvaddstr(1, 5, "example app")
-    >  window:attrset(curses.A_NORMAL)
-    >  for i=0,15 do
-    >    window:attrset(curses.color_pair(i))
-    >    window:mvaddstr(3+i, 5, "========================")
-    >  end
-    >  window:refresh()
-    >end
-- __teliva_timestamp: original
   menu:
     >-- To show app-specific hotkeys in the menu bar, add hotkey/command
     >-- arrays of strings to the menu array.
     >menu = {}
 - __teliva_timestamp: original
-  update:
-    >function update(window)
-    >  local key = window:getch()
-    >  -- process key here
-    >end
-- __teliva_timestamp: original
-  init_colors:
-    >function init_colors()
-    >  for i=0,7 do
-    >    curses.init_pair(i, i, -1)
-    >  end
-    >  curses.init_pair(8, 7, 0)
-    >  curses.init_pair(9, 7, 1)
-    >  curses.init_pair(10, 7, 2)
-    >  curses.init_pair(11, 7, 3)
-    >  curses.init_pair(12, 7, 4)
-    >  curses.init_pair(13, 7, 5)
-    >  curses.init_pair(14, 7, 6)
-    >  curses.init_pair(15, -1, 15)
-    >end
-- __teliva_timestamp: original
-  main:
-    >function main()
-    >  init_colors()
-    >
-    >  while true do
-    >    render(Window)
-    >    update(Window)
-    >  end
-    >end
-- __teliva_timestamp: original
-  doc:blurb:
-    >To show a brief description of the app on the 'big picture' screen, put the text in a special buffer called 'doc:blurb'.
-    >
-    >You can also override the default big picture screen entirely by creating a buffer called 'doc:main'.
+  Window:
+    >Window = curses.stdscr()
 - __teliva_timestamp: original
   window:
     >-- constructor for fake screen and window
@@ -346,8 +295,7 @@
     >  end
     >  return props
     >end
-- __teliva_timestamp:
-    >Thu Mar  3 22:04:15 2022
+- __teliva_timestamp: original
   check_screen:
     >function check_screen(window, contents, message)
     >  local x, y = 1, 1
@@ -433,3 +381,53 @@
     >    outfile:write(line)
     >  end
     >end
+- __teliva_timestamp: original
+  render:
+    >function render(window)
+    >  window:clear()
+    >  -- draw stuff to screen here
+    >  window:attron(curses.A_BOLD)
+    >  window:mvaddstr(1, 5, "example app")
+    >  window:attrset(curses.A_NORMAL)
+    >  for i=0,15 do
+    >    window:attrset(curses.color_pair(i))
+    >    window:mvaddstr(3+i, 5, "========================")
+    >  end
+    >  window:refresh()
+    >end
+- __teliva_timestamp: original
+  update:
+    >function update(window)
+    >  local key = window:getch()
+    >  -- process key here
+    >end
+- __teliva_timestamp: original
+  init_colors:
+    >function init_colors()
+    >  for i=0,7 do
+    >    curses.init_pair(i, i, -1)
+    >  end
+    >  curses.init_pair(8, 7, 0)
+    >  curses.init_pair(9, 7, 1)
+    >  curses.init_pair(10, 7, 2)
+    >  curses.init_pair(11, 7, 3)
+    >  curses.init_pair(12, 7, 4)
+    >  curses.init_pair(13, 7, 5)
+    >  curses.init_pair(14, 7, 6)
+    >  curses.init_pair(15, -1, 15)
+    >end
+- __teliva_timestamp: original
+  main:
+    >function main()
+    >  init_colors()
+    >
+    >  while true do
+    >    render(Window)
+    >    update(Window)
+    >  end
+    >end
+- __teliva_timestamp: original
+  doc:blurb:
+    >To show a brief description of the app on the 'big picture' screen, put the text in a special buffer called 'doc:blurb'.
+    >
+    >You can also override the default big picture screen entirely by creating a buffer called 'doc:main'.
diff --git a/toot-toot.tlv b/toot-toot.tlv
index 8d03654..66b0d9e 100644
--- a/toot-toot.tlv
+++ b/toot-toot.tlv
@@ -79,11 +79,11 @@
 - __teliva_timestamp: original
   check_eq:
     >function check_eq(x, expected, msg)
-    >  if x == expected then
+    >  if eq(x, expected) then
     >    Window:addch('.')
     >  else
     >    print('F - '..msg)
-    >    print('  expected '..tostring(expected)..' but got '..x)
+    >    print('  expected '..str(expected)..' but got '..str(x))
     >    teliva_num_test_failures = teliva_num_test_failures + 1
     >    -- overlay first test failure on editors
     >    if teliva_first_failure == nil then
@@ -92,6 +92,37 @@
     >  end
     >end
 - __teliva_timestamp: original
+  eq:
+    >function eq(a, b)
+    >  if type(a) ~= type(b) then return false end
+    >  if type(a) == 'table' then
+    >    if #a ~= #b then return false end
+    >    for k, v in pairs(a) do
+    >      if b[k] ~= v then
+    >        return false
+    >      end
+    >      return true
+    >    end
+    >  end
+    >  return a == b
+    >end
+- __teliva_timestamp: original
+  str:
+    >-- smarter tostring
+    >-- slow; used only for debugging
+    >function str(x)
+    >  if type(x) == 'table' then
+    >    local result = ''
+    >    result = result..#x..'{'
+    >    for k, v in pairs(x) do
+    >      result = result..str(k)..'='..str(v)..', '
+    >    end
+    >    result = result..'}'
+    >    return result
+    >  end
+    >  return tostring(x)
+    >end
+- __teliva_timestamp: original
   map:
     >-- only for arrays
     >function map(l, f)
@@ -147,16 +178,18 @@
     >  return result
     >end
 - __teliva_timestamp: original
-  Window:
-    >Window = curses.stdscr()
-    >curses.curs_set(0)  -- we'll simulate our own cursor
-- __teliva_timestamp: original
   menu:
+    >-- To show app-specific hotkeys in the menu bar, add hotkey/command
+    >-- arrays of strings to the menu array.
     >menu = {
     >  {'^k', 'clear'},
     >  {'^w', 'write prose to file "toot" (edit hotkey does NOT save)'},
     >}
 - __teliva_timestamp: original
+  Window:
+    >Window = curses.stdscr()
+    >curses.curs_set(0)  -- we'll simulate our own cursor
+- __teliva_timestamp: original
   main:
     >function main()
     >  init_colors()
diff --git a/zet.tlv b/zet.tlv
index 7a718aa..6105fda 100644
--- a/zet.tlv
+++ b/zet.tlv
@@ -79,11 +79,11 @@
 - __teliva_timestamp: original
   check_eq:
     >function check_eq(x, expected, msg)
-    >  if x == expected then
+    >  if eq(x, expected) then
     >    Window:addch('.')
     >  else
     >    print('F - '..msg)
-    >    print('  expected '..tostring(expected)..' but got '..x)
+    >    print('  expected '..str(expected)..' but got '..str(x))
     >    teliva_num_test_failures = teliva_num_test_failures + 1
     >    -- overlay first test failure on editors
     >    if teliva_first_failure == nil then
@@ -92,6 +92,37 @@
     >  end
     >end
 - __teliva_timestamp: original
+  eq:
+    >function eq(a, b)
+    >  if type(a) ~= type(b) then return false end
+    >  if type(a) == 'table' then
+    >    if #a ~= #b then return false end
+    >    for k, v in pairs(a) do
+    >      if b[k] ~= v then
+    >        return false
+    >      end
+    >      return true
+    >    end
+    >  end
+    >  return a == b
+    >end
+- __teliva_timestamp: original
+  str:
+    >-- smarter tostring
+    >-- slow; used only for debugging
+    >function str(x)
+    >  if type(x) == 'table' then
+    >    local result = ''
+    >    result = result..#x..'{'
+    >    for k, v in pairs(x) do
+    >      result = result..str(k)..'='..str(v)..', '
+    >    end
+    >    result = result..'}'
+    >    return result
+    >  end
+    >  return tostring(x)
+    >end
+- __teliva_timestamp: original
   map:
     >-- only for arrays
     >function map(l, f)
@@ -147,15 +178,47 @@
     >  return result
     >end
 - __teliva_timestamp: original
-  spaces:
-    >function spaces(n)
-    >  for i=1,n do
-    >    Window:addch(' ')
+  sort_letters:
+    >function sort_letters(s)
+    >  tmp = {}
+    >  for i=1,#s do
+    >    table.insert(tmp, s[i])
     >  end
+    >  table.sort(tmp)
+    >  local result = ''
+    >  for _, c in pairs(tmp) do
+    >    result = result..c
+    >  end
+    >  return result
+    >end
+    >
+    >function test_sort_letters(s)
+    >  check_eq(sort_letters(''), '', 'test_sort_letters: empty')
+    >  check_eq(sort_letters('ba'), 'ab', 'test_sort_letters: non-empty')
+    >  check_eq(sort_letters('abba'), 'aabb', 'test_sort_letters: duplicates')
     >end
 - __teliva_timestamp: original
-  Window:
-    >Window = curses.stdscr()
+  count_letters:
+    >function count_letters(s)
+    >  local result = {}
+    >  for i=1,string.len(s) do
+    >    local c = s[i]
+    >    if result[c] == nil then
+    >      result[c] = 1
+    >    else
+    >      result[c] = result[c] + 1
+    >    end
+    >  end
+    >  return result
+    >end
+- __teliva_timestamp: original
+  append:
+    >-- concatenate list 'elems' into 'l', modifying 'l' in the process
+    >function append(l, elems)
+    >  for i=1,#elems do
+    >    l[#l+1] = elems[i]
+    >  end
+    >end
 - __teliva_timestamp: original
   menu:
     >-- To show app-specific hotkeys in the menu bar, add hotkey/command
@@ -164,6 +227,170 @@
     >  {'^e', 'edit'},
     >}
 - __teliva_timestamp: original
+  Window:
+    >Window = curses.stdscr()
+- __teliva_timestamp: original
+  window:
+    >-- constructor for fake screen and window
+    >-- call it like this:
+    >--   local w = window{
+    >--     kbd=kbd('abc'),
+    >--     scr=scr{h=5, w=4},
+    >--   }
+    >-- eventually it'll do everything a real ncurses window can
+    >function window(h)
+    >  h.__index = h
+    >  setmetatable(h, h)
+    >  h.__index = function(table, key)
+    >    return rawget(h, key)
+    >  end
+    >  h.getch = function(self)
+    >    return table.remove(h.kbd, 1)
+    >  end
+    >  h.addch = function(self, c)
+    >    local scr = self.scr
+    >    if scr.cursy <= scr.h then
+    >      scr[scr.cursy][scr.cursx] = c
+    >      scr.cursx = scr.cursx+1
+    >      if scr.cursx > scr.w then
+    >        scr.cursy = scr.cursy+1
+    >        scr.cursx = 1
+    >      end
+    >    end
+    >  end
+    >  h.addstr = function(self, s)
+    >    for i=1,string.len(s) do
+    >      self:addch(s[i])
+    >    end
+    >  end
+    >  h.mvaddch = function(self, y, x, c)
+    >    self.scr.cursy = y
+    >    self.scr.cursx = x
+    >    self.addch(c)
+    >  end
+    >  h.mvaddstr = function(self, y, x, s)
+    >    self.scr.cursy = y
+    >    self.scr.cursx = x
+    >    self:addstr(s)
+    >  end
+    >  return h
+    >end
+- __teliva_timestamp: original
+  kbd:
+    >function kbd(keys)
+    >  local result = {}
+    >  for i=1,string.len(keys) do
+    >    table.insert(result, keys[i])
+    >  end
+    >  return result
+    >end
+- __teliva_timestamp: original
+  scr:
+    >function scr(props)
+    >  props.cursx = 1
+    >  props.cursy = 1
+    >  for y=1,props.h do
+    >    props[y] = {}
+    >    for x=1,props.w do
+    >      props[y][x] = ' '
+    >    end
+    >  end
+    >  return props
+    >end
+- __teliva_timestamp: original
+  check_screen:
+    >function check_screen(window, contents, message)
+    >  local x, y = 1, 1
+    >  for i=1,string.len(contents) do
+    >    check_eq(contents[i], window.scr[y][x], message..'/'..y..','..x)
+    >    x = x+1
+    >    if x > window.scr.w then
+    >      y = y+1
+    >      x = 1
+    >    end
+    >  end
+    >end
+    >
+    >-- putting it all together, an example test of both keyboard and screen
+    >function test_check_screen()
+    >  local lines = {
+    >    c='123',
+    >    d='234',
+    >    a='345',
+    >    b='456',
+    >  }
+    >  local w = window{
+    >    kbd=kbd('abc'),
+    >    scr=scr{h=3, w=5},
+    >  }
+    >  local y = 1
+    >  while true do
+    >    local c = w:getch()
+    >    if c == nil then break end
+    >    w:mvaddstr(y, 1, lines[c])
+    >    y = y+1
+    >  end
+    >  check_screen(w, '345  '..
+    >                  '456  '..
+    >                  '123  ',
+    >              'test_check_screen')
+    >end
+- __teliva_timestamp: original
+  start_reading:
+    >-- primitive for reading files from a file system (or, later, network)
+    >-- returns a channel or nil on error
+    >-- read lines from the channel using :recv()
+    >-- recv() on the channel will indicate end of file.
+    >function start_reading(fs, filename)
+    >  local result = task.Channel:new()
+    >  local infile = io.open(filename)
+    >  if infile == nil then return nil end
+    >  task.spawn(reading_task, infile, result)
+    >  return result
+    >end
+    >
+    >function reading_task(infile, chanout)
+    >  for line in infile:lines() do
+    >    chanout:send(line)
+    >  end
+    >  chanout:send(nil)  -- eof
+    >end
+- __teliva_timestamp: original
+  start_writing:
+    >-- primitive for writing files to a file system (or, later, network)
+    >-- returns a channel or nil on error
+    >-- write to the channel using :send()
+    >-- indicate you're done writing by calling :close()
+    >-- file will not be externally visible until :close()
+    >function start_writing(fs, filename)
+    >  local result = task.Channel:new()
+    >  local initial_filename = os.tmpname()
+    >  local outfile = io.open(initial_filename, 'w')
+    >  if outfile == nil then return nil end
+    >  result.close = function()
+    >    result:send(nil)  -- end of file
+    >    outfile:close()
+    >    os.rename(initial_filename, filename)
+    >  end
+    >  task.spawn(writing_task, outfile, result)
+    >  return result
+    >end
+    >
+    >function writing_task(outfile, chanin)
+    >  while true do
+    >    local line = chanin:recv()
+    >    if line == nil then break end  -- end of file
+    >    outfile:write(line)
+    >  end
+    >end
+- __teliva_timestamp: original
+  spaces:
+    >function spaces(n)
+    >  for i=1,n do
+    >    Window:addch(' ')
+    >  end
+    >end
+- __teliva_timestamp: original
   init_colors:
     >function init_colors()
     >  -- light background