diff --git a/the_parser.p8 b/the_parser.p8
new file mode 100644
index 0000000..8c0a0e2
--- /dev/null
+++ b/the_parser.p8
@@ -0,0 +1,61 @@
+pico-8 cartridge // http://www.pico-8.com
+version 41
+__lua__
+-- the parser
+
+parser = {}
+mknew(parser)
+
+-- calls parse_into with a nop
+-- emit function.
+function parser:parse(str)
+ self:parse_into(str, function() end)
+end
+
+-- read a file of commands and
+-- execute them, emitting the
+-- results from each call into
+-- `emit` as a table per row.
+--
+-- a "command" is a method on
+-- self. a row alternates
+-- commands with args. when
+-- calling a command, it also
+-- gets a table of previous
+-- results as the first arg.
+-- args are split on ','.
+function parser:parse_into(str, emit)
+ for row in all(split(str, "\n")) do
+  local prev = {}
+  local sectors = split(row, ":")
+  for i=1,#sectors,2 do
+   local x = self[sectors[i]](self, prev, usplit(sectors[i+1]))
+   if (x) add(prev, x)
+  end
+  emit(prev)
+ end
+end
+
+-- saves prev[sel] as self.name.
+-- if sel is unspecified, saves
+-- all of prev (as a table).
+function parser:saveas(prev, name, sel)
+ self[name] = sel and prev[sel] or prev
+end
+
+-- returns its args, ignoring
+-- prev. Used to stuff things
+-- into prev. args are packed
+-- if there's multiple.
+function parser:val(_, ...)
+ local ret := pack(...)
+ if (#ret == 1) return ret[1]
+ return ret
+end
+
+function parser:bind(_, fn, ...)
+ local f = self[fn]
+ return function()
+  f(...)
+ end
+end
diff --git a/updatedshmup.p8 b/updatedshmup.p8
index f43382e..190d776 100644
--- a/updatedshmup.p8
+++ b/updatedshmup.p8
@@ -26,22 +26,20 @@ end
 -- ret is definitely not nil
 -- before calling setmetatable.
 -- use to initialize mutables.
+--
+-- if there was a previous new,
+-- it is invoked on the new
+-- object *after* more, because
+-- this works better with the
+-- `more` impls i use.
 function mknew(tt, more)
- local mt = {__index=tt}
- -- check "more" only once ever
- if more then
-  tt.new = function(ret)
-   if (not ret) ret = {}
-   more(ret)
-   setmetatable(ret, mt)
-   return ret
-  end
- else
-  tt.new=function(ret)
-   if (not ret) ret = {}
-   setmetatable(ret, mt)
-   return ret
-  end
+ local mt,oldnew = {__index=tt},tt.new
+ tt.new=function(ret)
+  if(not ret) ret = {}
+  if(more) more(ret)
+  if(oldnew) oldnew(ret)
+  setmetatable(ret, mt)
+  return ret
  end
 end
 
@@ -121,7 +119,7 @@ function _init()
  init_blip_pals()
 	wipe_level()
 	primary_ship.main_gun = zap_gun.new()
-	load_level(example_level)
+	load_level(example_level_csv)
 	state = game
 	pal(2,129)
 	pal()
@@ -416,59 +414,6 @@ function grab_p1_butts()
  }
 end
 
--->8
--- the parser
-
-parser = {}
-mknew(parser)
-
--- calls parse_into with a nop
--- emit function.
-function parser:parse(str)
- self:parse_into(str, function() end)
-end
-
--- read a file of commands and
--- execute them, emitting the
--- results from each call into
--- `emit` as a table per row.
---
--- a "command" is a method on
--- self. a row alternates
--- commands with args. when
--- calling a command, it also
--- gets a table of previous
--- results as the first arg.
--- args are split on ','.
-function parser:parse_into(str, emit)
- for row in all(split(str, "\n")) do
-  local prev = {}
-  local sectors = split(row, ":")
-  for i=1,#sectors,2 do
-   local x = self[sectors[i]](self, prev, usplit(sectors[i+1]))
-   if (x) add(prev, x)
-  end
-  emit(prev)
- end
-end
-
--- saves prev[sel] as self.name.
--- if sel is unspecified, saves
--- all of prev (as a table).
-function parser:saveas(prev, name, sel)
- self[name] = sel and prev[sel] or prev
-end
-
--- returns its args, ignoring
--- prev. Used to stuff things
--- into prev. args are packed
--- if there's multiple.
-function parser:val(_, ...)
- local ret := pack(...)
- if (#ret == 1) return ret[1]
- return ret
-end
-
 -->8
 --ship behavior
 
@@ -603,520 +548,6 @@ function ship_m:refresh_shield()
  self.shield_refresh_ready = lframe + self.shieldcooldown
 end
 
--->8
---ships, including player
-
-firespark = split"9, 8, 2, 5, 1"
-smokespark = split"13, 13, 5, 5"
-
-player = ship_m.new{
- --shape
- sprite = 1, --index of ship sprite
- size = 1, --all ships are square; how many 8x8 sprites?
- hurt = { -- hurtbox - where this ship can be hit
-  x_off = 3, -- upper left corner
-  y_off = 2, -- relative to ship ulc
-  width = 1,
-  height = 3
- },
- sparks = firespark, -- see tab 9
- sparkodds = 2,
- boss = true,  -- dramatic special effects
- 
- -- health and power
- hp = 3, -- current health, non-regenerating
- maxhp = 3, -- player only; other ships never heal
- shield = 2, -- regenerates, using power
- maxshield = 2,
- shieldcost = 300, -- power cost to refill shield
- generator = 1.5,  -- 1 feels too slow
-
- -- gun
- main_gun = nil, -- assign at spawn time
- special_gun = nil,
- fire_off_x = 4,  -- offset where bullets come from
- fire_off_y = 0,
-
- -- position
- x=52, -- x and y are for upper left corner
- y=96,
- xmomentum = 0,
- ymomentum = 0,
- maxspd = 2.5, -- momentum cap
- thrust = 0.25, -- momentum added from button
- drag = 0.125, -- momentum lost per frame
- slip = false, -- does not slide down screen
- grab_butts = function(self)  -- fetch buttons
-  local butts = grab_p1_butts()
-  if butts[0] == butts[1] then
-   self.sprite = 1
-  elseif butts[0] > 0 then
-   self.sprite = 17
-  else
-   self.sprite = 18
-  end
-  return butts
- end
-}
-mknew(player,
- function(p)
-  p.main_gun = zap_gun.new()
- end
-)
-
-frownie = ship_m.new{
- --shape
- sprite = 3, --index of ship sprite
- size = 1, --all ships are square; how many 8x8 sprites?
- hurt = { -- hurtbox - where this ship can be hit
-  x_off = 0, -- upper left corner
-  y_off = 1, -- relative to ship ulc
-  width = 8,
-  height = 6
- },
- sparks = smokespark,
- sparkodds = 8,
- 
- -- health and power
- hp = 1, -- enemy ships need no max hp
-
- -- position
- x=60, -- x and y are for upper left corner
- y=8,
- xmomentum = 0,
- ymomentum = 0,
- maxspd = 2, -- momentum cap
- thrust = 0.12, -- momentum added from button
- drag = 0.07, -- momentum lost per frame
- slip = true,
- grab_butts = function(discard_self)
-  -- buttons are effectively analog
-  -- and negative buttons work just fine!
-  local butts = {}
-  local tstate = (1 + flr(4*t() + 0.5)) % 6
-  butts[0] = ((tstate==1 or tstate==2) and 1) or 0
-  butts[1] = ((tstate==4 or tstate==5) and 1) or 0
-  for b=2, 5 do
-   butts[b]=0
-  end
-  return butts
- end, -- button fetch algorithm
-}
-mknew(frownie)
-
-blocky = frownie.new{
- sprite = 10,
- hp = 2,
- hurt = {
-  x_off = 0,
-  y_off = 0,
-  width = 8,
-  height = 7
- },
- 
- ow = function(self)
-  if self.hp <= 1 then
-   self.sprite = 11
-  else
-   self.sprite = 10
-  end
-  ship_m.ow(self)
- end
-}
-mknew(blocky)
-
-function spawn_spewy_at(x, y)
-	local spewy = frownie.new{
-	 x = x,
-	 y = y,
-	 sprite = 26,
-	 power = -20,
-	 hurt = {
-	  x_off = 0,
-   y_off = 1,
-   width = 8,
-   height = 5
-  },
- 
-	 hp = 1,
-	 maxpower = 70,
-	 generator = 0.5,
-	 main_gun = protron_gun.new{enemy=true},
-	 fire_off_x = 4,
-	 fire_off_y = 7,
-	 grab_butts = function()
-	  local butts = frownie.grab_butts()
-	  butts[5] = 1
-	  return butts
-	 end,
-	}
- eships:push_back(spewy)
-	return spewy
-end
-
-chasey = ship_m.new{
- sprite = 5,
- size = 1,
- hurt = {
-  x_off = 1,
-  y_off = 2,
-  width = 6,
-  height = 5,
- },
- sparks = smokespark,
- sparkodds = 8,
- hp = 2,
- shield = 1,
- maxshield = 1,
- shieldcost = 180,
-
- fire_off_x = 4,
- fire_off_y = 7,
- 
- maxspd = 2,
- thrust = 0.2,
- drag = 0.075,
- slip = true,
-
- grab_butts = function(self)
-  local butts = {0,0,0,0,0}
-  butts[0] = 0
-  if (self.x < primary_ship.x) butts[1] = 1
-  if (self.x > primary_ship.x) butts[0] = 1
-  if (self.x - 16 < primary_ship.x and self.x + 16 > primary_ship.x) butts[5] = 1
-  return butts
- end,
-}
-mknew(chasey)
-
-function spawn_chasey_at(x, y)
- local c = chasey.new{
-  x = x,
-  y = y,
-  main_gun = zap_gun.new{enemy=true},
- }
- eships:push_back(c)
- return c
-end
-
-function spawn_xl_chasey_at(x, y)
- local c = chasey.new{
-  x = x,
-  y = y,
-  size = 2,
-  maxspd = 1.25,
-  hurt = {
-   x_off = 2,
-   y_off = 4,
-   width = 12,
-   height = 10
-  },
-  hp = 20,
-  shield = 5,
-  boss = true,
-  slip = false,
-  main_gun = zap_gun.new{enemy=true},
-  grab_butts = function(self)
-   local butts = chasey.grab_butts(self)
-   if (self.y < 4) butts[3] = 1
-   return butts
-  end,
-  draw = function(self)
-   if(self.fx_pal) pal(self.fx_pal)
-   sspr(40, 0, 8, 8, self.x, self.y, 16, 16)
-   pal()
-  end,
- }
- eships:push_back(c)
- return c
-end
--->8
--- collisions
-
--- box: x, y, width, height
-
-function collides(box1, box2)
-	return not (
-	  box1.x>box2.x+box2.width
-	  or box1.y>box2.y+box2.height
-	  or box1.x+box1.width<box2.x
-	  or box1.y+box1.height<box2.y)
-end
-
-collider = { }
-mknew(collider,
- function(x)
-  x.suppress = {}
- end
-)
-
-function collider_indexes(box)
- local ret = {}
- for x = box.x\8, (box.x+box.width)\8 do
-  for y = box.y\8, (box.y+box.height)\8 do
-   add(ret, x+256*y)
-  end
- end
- return ret
-end
-
-function collider:insert(item)
- -- todo: separate "big items" list?
- local bdx = collider_indexes(hurtbox(item))
- for i in all(bdx) do
-  local x = self[i]
-  if not x then
-   x = {}
-   self[i] = x
-  end
-  add(x, item)
- end
-end
-
-function collider:hide(item)
- self.suppress[item]=true
-end
-
-function collider:get_collisions(item)
- local found = { }
- local seen = { }
- local box = hurtbox(item)
- local bucket_ids = collider_indexes(box)
- for b_idx in all(bucket_ids) do
-  local bucket = self[b_idx]
-  if bucket then
-   for candidate in all(bucket) do
-    if not (seen[candidate] or self.suppress[candidate]) then
-     seen[candidate] = true
-     if (collides(box, hurtbox(candidate))) add(found, candidate)
-    end
-   end
-  end
- end
- return found
-end
--->8
--- level and event system
-
--- a level is a map from
--- effective frame number to
--- callback for that frame.
-
--- effective frame number stops
--- when freeze count is nonzero
-
--- a level is won when it hits
--- the end-of-level sentinel 
--- and there are no more
--- tracked enemies.
--- lost when there are no
--- player ships left.
-
--- effective frame
-distance = 0
--- actual frame count since
--- start of level times 0x0.0001
-lframe = 0
-
--- do not advance distance when
--- nonzero
-freeze = 0
-
-eol = {}
-
-function load_level(lvltbl)
- distance = 0
- lframe = 0
- freeze = 0
- current_level = {}
- -- copy the level so we can
- -- modify it dynamically
- -- without losing the original
- for frame, cb in pairs(lvltbl) do
-  current_level[frame] = cb
- end
- leveldone = false
-end
-
-function level_frame()
- lframe += 0x0.0001
- if (current_level == nil) return true
- if freeze == 0 then 
-  distance += 1
-  local cb = current_level[distance]
-  if cb ~= nil then
-   if cb == eol then
-    current_level = nil
-    return true
-   else
-    cb()
-   end
-  end
- end
- return false
-end
--->8
--- example level
-
-function spawn_rnd_x(typ)
- s = typ.new{
-  x = rnd(104),
-  y = -(typ.size * 8 - 1)
- }
- eships:push_back(s)
- return s
-end
-
-function spawn_blocking_rnd_x(typ)
- freeze += 1
- s = typ.new{
-  x = rnd(104),
-  y = -7,
-  ice = 1,
-  orig_die = typ.die,
-  die = function(self)
-   freeze -= self.ice
-   self.ice = 0
-   self:orig_die()
-  end
- }
- eships:push_back(s)
- return s
-end
-
-function spawn_frownie()
- return spawn_rnd_x(frownie)
-end
-
-function spawn_blocking_frownie()
- spawn_blocking_rnd_x(frownie)
-end
-
-function spawn_blocky()
- spawn_rnd_x(blocky)
-end
-
-function spawn_blocking_blocky()
- spawn_blocking_rnd_x(blocky)
-end
-
-function spawn_spewy()
- return spawn_spewy_at(rnd(104), -7)
-end
-
-function spawn_chasey()
- return spawn_chasey_at(rnd(104), -7)
-end
-
-function spawn_blocking_spewy()
- freeze += 1
- local s = spawn_spewy()
- s.ice = 1
- s.die = function(self)
-  freeze -= self.ice
-  self.ice = 0
-  frownie.die(self)
- end
-end
-
-function spawn_bonus_frownie()
- local f = spawn_frownie()
- f.sprite = 7
- f.die = function(self)
-  spawn_repair_at(self.x+4, self.y+4)
-  frownie.die(self)
- end
-end 
-
-function spawn_bonus_vulcan_chasey()
- local c = spawn_chasey()
- c.main_gun=vulcan_gun.new{enemy=true}
- c.die = function(self)
-  spawn_main_gun_at(self.x-1, self.y-1, vulcan_gun)
-  chasey.die(self)
- end
- c.sprite=4
- return c
-end 
-
-helpers = {
- spawn_frownie,
- spawn_frownie,
- spawn_frownie,
- spawn_blocky,
- spawn_blocky,
- spawn_chasey,
- spawn_spewy,
-}
-
-function spawn_blocking_boss_chasey()
- freeze += 1
- local c = spawn_xl_chasey_at(44, -15)
- c.ice = 1
- c.die = function(self)
-  freeze -= self.ice
-  self.ice = 0
-  chasey.die(self)
- end
-
- local nextspawn = lframe + 0x0.0080
- events:push_back{move=function()
-  if lframe >= nextspawn then
-   helpers[flr(rnd(#helpers))+1]()
-   nextspawn += 0x0.0040
-  end
-  return c.dead
- end}
- 
- return c
-end
-
-example_level = {
- [1]=spawn_frownie,
- [60]=spawn_bonus_vulcan_chasey,
- [61]=spawn_blocky,
- [85]=spawn_spewy,
- [100]=spawn_spewy,
- [115]=spawn_spewy,
- [130]=spawn_bonus_frownie,
- [145]=spawn_spewy,
- [200]=spawn_chasey,
- [250]=spawn_blocking_blocky,
- [285]=function()
-  spawn_spec_gun_at(35, -11, blast_gun)
- end,
- [310]=function()
-  spawn_blocking_blocky()
-  spawn_blocking_blocky()
-  spawn_blocking_blocky()
- end,
- [311]=spawn_frownie,
- [350]=function()
-  spawn_main_gun_at(70, -11, protron_gun)
- end,
- [401]=spawn_frownie,
- [420]=spawn_blocking_frownie,
- [430]=spawn_bonus_vulcan_chasey,
- [450]=spawn_frownie,
- [465]=spawn_bonus_frownie,
- [480]=spawn_chasey,
- [500]=function()
-  local tnext = lframe
-  local remain = 20
-  events:push_back{move=function()
-   if (lframe < tnext) return false
-   spawn_blocking_blocky()
-   tnext = lframe + 0x0.000c
-   remain -= 1
-   return (remain <= 0) 
-  end}
- end,
- [501]=spawn_bonus_frownie,
- [620]=spawn_blocking_blocky,
- [700]=spawn_blocking_boss_chasey,
- [701]=eol
-}
-
 -->8
 -- bullet and gun behaviors
 
@@ -1395,6 +826,540 @@ vulcan_gun = gun_base.new{
 }
 mknew(vulcan_gun)
 
+-->8
+--ships, including player
+
+firespark = split"9, 8, 2, 5, 1"
+smokespark = split"13, 13, 5, 5"
+
+player = ship_m.new{
+ --shape
+ sprite = 1, --index of ship sprite
+ size = 1, --all ships are square; how many 8x8 sprites?
+ hurt = { -- hurtbox - where this ship can be hit
+  x_off = 3, -- upper left corner
+  y_off = 2, -- relative to ship ulc
+  width = 1,
+  height = 3
+ },
+ sparks = firespark, -- see tab 9
+ sparkodds = 2,
+ boss = true,  -- dramatic special effects
+ 
+ -- health and power
+ hp = 3, -- current health, non-regenerating
+ maxhp = 3, -- player only; other ships never heal
+ shield = 2, -- regenerates, using power
+ maxshield = 2,
+ shieldcost = 300, -- power cost to refill shield
+ generator = 1.5,  -- 1 feels too slow
+
+ -- gun
+ main_gun = nil, -- assign at spawn time
+ special_gun = nil,
+ fire_off_x = 4,  -- offset where bullets come from
+ fire_off_y = 0,
+
+ -- position
+ x=52, -- x and y are for upper left corner
+ y=96,
+ xmomentum = 0,
+ ymomentum = 0,
+ maxspd = 2.5, -- momentum cap
+ thrust = 0.25, -- momentum added from button
+ drag = 0.125, -- momentum lost per frame
+ slip = false, -- does not slide down screen
+ grab_butts = function(self)  -- fetch buttons
+  local butts = grab_p1_butts()
+  if butts[0] == butts[1] then
+   self.sprite = 1
+  elseif butts[0] > 0 then
+   self.sprite = 17
+  else
+   self.sprite = 18
+  end
+  return butts
+ end
+}
+mknew(player,
+ function(p)
+  p.main_gun = zap_gun.new()
+ end
+)
+
+frownie = ship_m.new{
+ --shape
+ sprite = 3, --index of ship sprite
+ size = 1, --all ships are square; how many 8x8 sprites?
+ hurt = { -- hurtbox - where this ship can be hit
+  x_off = 0, -- upper left corner
+  y_off = 1, -- relative to ship ulc
+  width = 8,
+  height = 6
+ },
+ sparks = smokespark,
+ sparkodds = 8,
+ 
+ -- health and power
+ hp = 1, -- enemy ships need no max hp
+
+ -- position
+ x=60, -- x and y are for upper left corner
+ y=8,
+ xmomentum = 0,
+ ymomentum = 0,
+ maxspd = 2, -- momentum cap
+ thrust = 0.12, -- momentum added from button
+ drag = 0.07, -- momentum lost per frame
+ slip = true,
+ grab_butts = function(discard_self)
+  -- buttons are effectively analog
+  -- and negative buttons work just fine!
+  local butts = {}
+  local tstate = (1 + flr(4*t() + 0.5)) % 6
+  butts[0] = ((tstate==1 or tstate==2) and 1) or 0
+  butts[1] = ((tstate==4 or tstate==5) and 1) or 0
+  for b=2, 5 do
+   butts[b]=0
+  end
+  return butts
+ end, -- button fetch algorithm
+}
+mknew(frownie)
+
+blocky = frownie.new{
+ sprite = 10,
+ hp = 2,
+ hurt = {
+  x_off = 0,
+  y_off = 0,
+  width = 8,
+  height = 7
+ },
+ 
+ ow = function(self)
+  if self.hp <= 1 then
+   self.sprite = 11
+  else
+   self.sprite = 10
+  end
+  ship_m.ow(self)
+ end
+}
+mknew(blocky)
+
+spewy = frownie.new{
+ sprite=26,
+ power=-20,
+ hurt = {
+  x_off=0,
+  y_off=1,
+  width=8,
+  height=5
+ },
+ hp=1,
+ maxpower=70,
+ generator=0.5,
+ fire_off_x=4,
+ fire_off_y = 7,
+ grab_butts=function()
+  local butts=frownie.grab_butts()
+  butts[5]=1
+  return butts
+ end
+}
+mknew(spewy, function(ship)
+ ship.main_gun=ship.main_gun or protron_gun.new{enemy=true}
+end)
+
+chasey = ship_m.new{
+ sprite = 5,
+ size = 1,
+ hurt = {
+  x_off = 1,
+  y_off = 2,
+  width = 6,
+  height = 5,
+ },
+ sparks = smokespark,
+ sparkodds = 8,
+ hp = 2,
+ shield = 1,
+ maxshield = 1,
+ shieldcost = 180,
+
+ fire_off_x = 4,
+ fire_off_y = 7,
+ 
+ maxspd = 2,
+ thrust = 0.2,
+ drag = 0.075,
+ slip = true,
+}
+mknew(chasey, function(ship)
+ ship.main_gun=ship.main_gun or zap_gun.new{enemy=true}
+end)
+
+function chasey:grab_butts()
+ local butts = {[0]=0,0,0,0,0,0}
+ if (self.x < primary_ship.x) butts[1] = 1
+ if (self.x > primary_ship.x) butts[0] = 1
+ if (self.x - 16 < primary_ship.x and self.x + 16 > primary_ship.x) butts[5] = 1
+ return butts
+end
+
+xl_chasey=chasey.new{
+ size=2,
+ maxspd=1.25,
+ hurt = {
+  x_off = 2,
+  y_off = 4,
+  width = 12,
+  height = 10
+ },
+ hp = 20,
+ shield = 5,
+ boss = true,
+ slip = false,
+ grab_butts = function(self)
+  local butts = chasey.grab_butts(self)
+  if (self.y < 4) butts[3] = 1
+  return butts
+ end,
+ draw = function(self)
+  if(self.fx_pal) pal(self.fx_pal)
+  sspr(40, 0, 8, 8, self.x, self.y, 16, 16)
+  pal()
+ end,
+}
+mknew(xl_chasey, function(ship)
+ ship.main_gun=ship.main_gun or zap_gun.new{enemy=true}
+end)
+-->8
+-- collisions
+
+-- box: x, y, width, height
+
+function collides(box1, box2)
+	return not (
+	  box1.x>box2.x+box2.width
+	  or box1.y>box2.y+box2.height
+	  or box1.x+box1.width<box2.x
+	  or box1.y+box1.height<box2.y)
+end
+
+collider = { }
+mknew(collider,
+ function(x)
+  x.suppress = {}
+ end
+)
+
+function collider_indexes(box)
+ local ret = {}
+ for x = box.x\8, (box.x+box.width)\8 do
+  for y = box.y\8, (box.y+box.height)\8 do
+   add(ret, x+256*y)
+  end
+ end
+ return ret
+end
+
+function collider:insert(item)
+ -- todo: separate "big items" list?
+ local bdx = collider_indexes(hurtbox(item))
+ for i in all(bdx) do
+  local x = self[i]
+  if not x then
+   x = {}
+   self[i] = x
+  end
+  add(x, item)
+ end
+end
+
+function collider:hide(item)
+ self.suppress[item]=true
+end
+
+function collider:get_collisions(item)
+ local found = { }
+ local seen = { }
+ local box = hurtbox(item)
+ local bucket_ids = collider_indexes(box)
+ for b_idx in all(bucket_ids) do
+  local bucket = self[b_idx]
+  if bucket then
+   for candidate in all(bucket) do
+    if not (seen[candidate] or self.suppress[candidate]) then
+     seen[candidate] = true
+     if (collides(box, hurtbox(candidate))) add(found, candidate)
+    end
+   end
+  end
+ end
+ return found
+end
+-->8
+-- level and event system
+
+-- a level is a map from
+-- effective frame number to
+-- a list of actions for that
+-- frame. an action is a
+-- method name and its args.
+
+-- effective frame number stops
+-- when freeze count is nonzero
+
+-- a level is won when it hits
+-- the end-of-level sentinel 
+-- and there are no more
+-- tracked enemies.
+-- lost when there are no
+-- player ships left.
+
+-- effective frame
+distance = 0
+-- actual frame count since
+-- start of level times 0x0.0001
+lframe = 0
+
+-- do not advance distance when
+-- nonzero
+freeze = 0
+
+eol = {}
+
+function load_level(levelfile)
+ distance = 0
+ lframe = 0
+ freeze = 0
+ leveldone = false
+ current_level = {}
+ local found_eol = false
+ if (type(levelfile)=="string") levelfile = csv(levelfile)
+ for row in all(levelfile) do
+  local x = current_level[row[1]]
+  if row[2] == "eol" then
+   found_eol = true
+   assert(x==nil, "events on eol frame")
+   current_level[row[1]] = eol
+  else
+   row.next = x
+   current_level[row[1]]=row
+  end
+ end
+ assert(found_eol)
+end
+
+function level_frame()
+ lframe += 0x0.0001
+ if (current_level == nil) return true
+ if freeze == 0 then 
+  distance += 1
+  local cbs = current_level[distance]
+  if cbs ~= nil then
+   if cbs == eol then
+    current_level = nil
+    return true
+   else
+    while cbs do
+     assert(cbs[1] == distance)
+     local f = _ENV[cbs[2]]
+     assert(type(f) == "function", cbs[2].." at "..distance.." is not a function")
+     f(unpack(cbs, 3))
+     cbs=cbs.next
+    end
+   end
+  end
+ end
+ return false
+end
+-->8
+-- example level
+
+function spawn_blocking_rnd_x(typ)
+ freeze += 1
+ s = typ.new{
+  x = rnd(104),
+  y = -7,
+  ice = 1,
+  orig_die = typ.die,
+  die = function(self)
+   freeze -= self.ice
+   self.ice = 0
+   self:orig_die()
+  end,
+ }
+ eships:push_back(s)
+ return s
+end
+
+function spawn_frownie()
+ return spawn_rnd(frownie)
+end
+
+function spawn_blocking_frownie()
+ spawn_blocking_rnd_x(frownie)
+end
+
+function spawn_blocky()
+ spawn_rnd(blocky)
+end
+
+function spawn_blocking_blocky()
+ spawn_rnd(blocky, 1)
+end
+
+function spawn_spewy()
+ return spawn_rnd(spewy)
+end
+
+function spawn_chasey()
+ return spawn_rnd(chasey)
+end
+
+function spawn_blocking_spewy()
+ freeze += 1
+ local s = spawn_spewy()
+ s.ice = 1
+ s.die = function(self)
+  freeze -= self.ice
+  self.ice = 0
+  frownie.die(self)
+ end
+end
+
+function spawn_bonus_frownie()
+ local f = spawn_frownie()
+ f.sprite = 7
+ f.die = function(self)
+  spawn_repair_at(self.x+4, self.y+4)
+  frownie.die(self)
+ end
+end 
+
+function spawn_bonus_vulcan_chasey()
+ local c = spawn_chasey()
+ c.main_gun=vulcan_gun.new{enemy=true}
+ c.die = function(self)
+  spawn_main_gun_at(self.x-1, self.y-1, vulcan_gun)
+  chasey.die(self)
+ end
+ c.sprite=4
+ return c
+end 
+
+helpers = {
+ spawn_frownie,
+ spawn_frownie,
+ spawn_frownie,
+ spawn_blocky,
+ spawn_blocky,
+ spawn_chasey,
+ spawn_spewy,
+}
+
+function spawn_blocking_boss_chasey()
+ local c = spawn_rnd(xl_chasey, 1)
+ local nextspawn = lframe + 0x0.0080
+ events:push_back{move=function()
+  if lframe >= nextspawn then
+   helpers[flr(rnd(#helpers))+1]()
+   nextspawn += 0x0.0040
+  end
+  return c.dead
+ end}
+ 
+ return c
+end
+
+function std_spawn(tnm, n, blocking, goodie,altspr)
+ local typ = _ENV[tnm]
+ assert(typ and typ.new, tostr(tnm).." not a class")
+ for i=1,(n or 1) do
+  spawn_rnd(typ, blocking, goodie,altspr)
+ end
+end
+
+-- blocking: 1 or 0
+function spawn_rnd(typ, blocking, goodie,altspr)
+ blocking = blocking or 0
+ freeze += blocking
+ s = typ.new{
+  x = rnd(104),
+  y = -(typ.size * 8 - 1),
+  ice=blocking,
+  die=function(self)
+   freeze -= self.ice
+   self.ice=0
+   typ.die(self)
+   spawn_goodie(goodie, self.x, self.y, self.size)
+  end,
+ }
+ if (altspr) s.spr = altspr
+ eships:push_back(s)
+ return s
+end
+
+-- TODO: spawn_goodie compatible versions of gun drops
+-- TODO: goodie table
+function spawn_goodie(goodie_name, x, y, sz)
+ if (not goodie_name or #goodie_name == 0) return
+ local sh = sz and sz/2 or 0
+ goodies[goodie_name].new{}:spawn_at(x+sh,y+sh)
+end
+
+function multi(times, interval, fnm, ...)
+ local f,irm,vargs = _ENV[fnm],interval,pack(...)
+ assert(type(f) == "function", fnm.." not a function")
+ f(...)
+ events:push_back{move=function()
+  irm-=1
+  if irm <= 0 then
+   irm=interval
+   times-=1
+   f(unpack(vargs))
+   return times <= 1
+  end
+ end}
+end
+
+-- then convert sample_level to csv.
+-- spawn_spec_gun_at and spawn_main_gun_at will need parsed forms.
+-- the boss also needs to be reachable, but one-off is fine.
+-- each row of level csv is offset,event,event-args...
+-- where offset,eol is a special case.
+
+example_level_csv=[[1,spawn_frownie
+60,spawn_bonus_vulcan_chasey
+61,spawn_blocky
+85,spawn_spewy
+100,spawn_spewy
+115,spawn_spewy
+130,spawn_bonus_frownie
+145,spawn_spewy
+200,spawn_chasey
+250,spawn_blocking_blocky
+285,spawn_spec_gun_at,35,-11,blast_gun
+310,spawn_blocking_blocky
+310,spawn_blocking_blocky
+310,spawn_blocking_blocky
+311,spawn_frownie
+350,spawn_main_gun_at,70,-11,protron_gun
+401,spawn_frownie
+420,spawn_blocking_frownie
+430,spawn_bonus_vulcan_chasey
+450,spawn_frownie
+465,spawn_bonus_frownie
+480,spawn_chasey
+500,multi,20,12,spawn_blocking_blocky
+501,spawn_bonus_frownie
+620,spawn_blocking_blocky
+700,spawn_blocking_boss_chasey
+701,eol]]
+
 -->8
 -- readme.md
 
@@ -1969,6 +1934,7 @@ gun_swap = powerup.new{
 mknew(gun_swap)
 
 function spawn_main_gun_at(x, y, gunt)
+ if (type(gunt)=="string") gunt=_ENV[gunt]
  local gun_p = gun_swap.new{
   gun = gunt.new()
  }
@@ -1982,6 +1948,7 @@ spec_gun_pl = {
 }
 
 function spawn_spec_gun_at(x, y, gunt)
+ if (type(gunt)=="string") gunt=_ENV[gunt]
  local gun_p = gun_swap.new{
   gun = gunt.new(),
   hitship = function(self, ship)