fix precedence error

not enough room to describe "fractions add up" -- maybe I can just fit
in the "remainder" to hint that it will be considered in future
upgrades?

.gitignore

@@ -0,0 +1,2 @@
+.DS_Store
+.vscode/settings.json

autobrake_test.p8

@@ -0,0 +1,244 @@
+pico-8 cartridge // http://www.pico-8.com
+version 41
+__lua__
+
+-- vacuum gambit automatic brake test
+-- by kistaro windrider
+
+function usplit(str)
+ return unpack(split(str))
+end
+function csv(s)
+ local ret = split(s, "\n")
+ for i, v in ipairs(ret) do
+  ret[i] = type(v) == "string" and split(v) or { v }
+ end
+ return ret
+end
+
+-- generate standard "overlay"
+-- constructor for type tt.
+-- if more is defined, generated
+-- new calls more(ret) after
+-- 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, 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
+
+function _init()
+ pal(1,129,1)
+ the_ship = ship.new()
+ constraints:setup()
+ slomo = 1
+ sloc = 0
+ reroll()
+end
+
+function reroll()
+ frames=0
+ sloc=0
+ the_ship:reroll()
+end
+
+function _update60()
+ if (btnp(4)) reroll()
+ if (btnp(5)) constraints:cycle()
+ if (btnp(3)) slomo <<= 1
+ if (btnp(2)) slomo >>= 1
+ slomo = (slomo < 1) and 1 or (slomo > 8192) and 8192 or slomo
+ sloc += 1
+ if sloc >= slomo then
+  frames += 1
+  the_ship:update()
+  sloc=0
+ end
+end
+
+function _draw()
+ cls(1)
+ constraints:draw()
+ the_ship:draw()
+ print("frames: " .. frames, 4, 64, 7)
+ print("speed: 1/" .. slomo, 8, 70, 7)
+
+ print("thrust: ".. actual_t, 4, 80, 7)
+ meter(80, 80, 128, 84, actual_t/the_ship.thrust/2)
+ print("dx: ".. the_ship.dx, 20, 86, 7)
+ meter(80, 86, 128, 90, the_ship.dx/the_ship.maxspd/2)
+ print("x: "..the_ship.x, 24, 92, 7)
+ print("bx: "..gbx, 20, 98, 7)
+
+ print("xmin:"..tostr(constraints.xmin), 12, 108, 7)
+ print("xmax:"..tostr(constraints.xmax), 12, 114, 7)
+end
+
+function meter(x0, y0, x1, y1, frac)
+ local c = 11
+ if frac < 0 then
+  frac = -frac
+  c = 8
+ end
+ local range = x1-x0
+ local midpoint = x0 + (range/2)
+ rectfill(x0, y0-1, x0, y1+1, 13)
+ rectfill(midpoint, y0-1, midpoint, y1 + 1, 13)
+ local width = range * frac
+ if (width ~= 0) rectfill(x0, y0, x0 + width, y1, c)
+end
+
+-->8
+-- ship
+
+ship = {
+ maxspd=4,
+ thrust=0.25,
+ drag=0.0625,
+ y=32,
+}
+mknew(ship)
+
+function ship:reroll()
+ self.x=rnd(128)
+ self.dx=rnd(2*self.maxspd)-self.maxspd
+end
+
+function ship:draw()
+ if self.x < -7 then
+  spr(2, 0, self.y-7)
+  spr(2, 0, self.y+8)
+ elseif self.x > 127 then
+  spr(2, 120, self.y-7, 1, 1, true)
+  spr(2, 120, self.y+8, 1, 1, true)
+ else
+  spr(1,self.x,self.y)
+ end
+
+ --if (self.dx == 0) return
+ local bd, f = brake_dist(self.dx, self.thrust + self.drag)
+ gbx = self.x+bd
+ spr(3, gbx-2,self.y-2)
+ print(tostr(f), gbx-2, self.y - 8, 14)
+end
+
+function calc_velocity(v0, t, vmax, drag)
+ v0 = mid(v0 + t, vmax, -vmax)
+ return v0 - mid(drag, -drag, v0)
+end
+
+function ship:update()
+ local t = btn(0) and -1 or btn(1) and 1 or 0
+ t *= self.thrust
+ t = constraints:constrain(self, t)
+ -- t = constraints:constrain(self, t)
+ -- t = constraints:constrain(self, t)
+ local s = calc_velocity(self.dx, t, self.maxspd, self.drag)
+
+ self.x += s
+ self.dx = s
+ actual_t = t
+end
+
+-->8
+-- constraints
+
+constraints = {
+ ymin=20,
+ ymax=52,
+ color=10
+}
+
+function constraints:constrain(s, want)
+ self.color=10
+ if (not self.xmin) return want
+
+ -- bmx: brake max
+ local v1, bmx = calc_velocity(s.dx, want, s.maxspd, s.drag), s.thrust + s.drag
+ local bd, bf = brake_dist(v1, bmx)
+ local bx, txm = s.x + bd + v1, self.xmax
+ if bx < self.xmin then
+  -- predicted brake point left
+  -- of xmin; apply max reverse
+  -- thrust, treat xmin as our
+  -- max target, and handle
+  -- overbraking by coalescing
+  -- with past +xmax case
+  self.color = 9
+  want = s.thrust
+  txm = self.xmin
+  v1 = calc_velocity(s.dx, want, s.maxspd, s.drag)
+  bd, bf = brake_dist(v1, bmx)
+  bx  = bd + s.x + v1
+ end
+ if (bx <= txm) return want
+ self.color = 8
+ local overage = bx - txm
+ want -= overage/max(bf,1)
+ if (want < -s.thrust) want = -s.thrust
+ return want
+end
+
+function brake_dist(v0, brake_max)
+ local tri_frames = abs(v0\brake_max)
+ local chunks = tri_frames * (tri_frames - 1) >> 1
+ local chunk_zone = chunks * brake_max
+ local overage = abs(v0) - tri_frames * brake_max
+ return (chunk_zone + overage * (tri_frames + 1)) * sgn(v0), (overage > 0) and tri_frames + 1 or tri_frames
+end
+
+function constraints:cycle()
+ if self.ctype=="bounds" then
+  self.ctype="point"
+ elseif self.ctype=="point" then
+  self.ctype="off"
+ else
+  self.ctype="bounds"
+ end
+ self:setup()
+end
+
+function constraints:setup()
+ if self.ctype=="point" then
+  self.xmin = 64
+  self.xmax = 64
+ elseif self.ctype=="bounds" then
+  self.xmin = 32
+  self.xmax = 96
+ else
+  self.xmin = nil
+  self.xmax = nil
+ end
+end
+
+function constraints:draw()
+ if (not self.xmin) return
+ rect(self.xmin, self.ymin, self.xmax, self.ymax, self.color)
+end
+
+-->8
+-- fx
+
+-- todo: spark ring buffer
+
+__gfx__
+000000008000000000080000a000a000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
+00000000006666000080000009090000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
+00000000067777600800000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
+00000000675555758008888009090000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
+000000006750007508000000a000a000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
+00000000067777500080000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
+00000000005555000008000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000

code-of-conduct.md

@@ -0,0 +1 @@
+Trans rights.

genericshmup.p8

@@ -75,7 +75,7 @@ function updategame()
 	edeaths = {}
 	for ip, ps in ipairs(pships) do
 	 for ie, eb in ipairs(ebullets) do
-	  if collides(hurtobx(ps), hurtbox(eb)) then
+	  if collides(hurtbox(ps), hurtbox(eb)) then
 	   if (eb:hitship(ps)) add(edeaths, ie)
 	   if ps:hitbullet(eb) then
 	    add(pdeaths, ip)

old_readme.md

@@ -0,0 +1,356 @@
+This file contains text that used to be in the cartridge itself, but
+I'm getting increasingly anxious about cartridge space so I'm moving
+it out ot a separate file.
+
+---
+
+main loop sequence
+==================
+1. level_frame
+2. events
+3. merge new_events into events
+4. update bg intangibles
+5. move ships (player first)
+6. move bullets (player first)
+7. calculate collisions
+ 1. pship on eship
+ 2. ebullet on pship
+ 3. pbullet on eship
+8. update fg intangibles
+9. check for end of level
+
+draw order
+----------
+bottom to top:
+1. intangibles_bg
+2. player bullets
+3. player ships
+4. enemy ships
+5. enemy bullets
+6. intangibles_fg
+
+notes
+-----
+intangibles_fg move()s after
+all collisions and other moves
+are processed. if an intangible
+is added to the list as a result
+of a collision or move, it will
+itself be move()d before it is
+drawn.
+
+data-driven items
+=================
+guns and bullets both allow the
+most common behaviors to be
+expressed with data alone.
+ships only need a movement
+algorithm expressed.
+
+guns
+----
+* t - metatable for bullet type.
+  fired once in the bullet's
+  default direction per shot.
+* enemy - if true, fired bullets
+  are flagged as enemy bullets.
+* icon - sprite index of an
+  8x8 sprite to display in the
+  hud when the player has this
+  gun. default is 20, a generic
+  crosshair bullseye thing.
+* cooldown - min frames between
+  shots.
+* ammo, maxammo - permitted
+  number of shots. 0 is empty
+  and unfireable. maxammo = 0
+  will cause a divide by zero
+  so don't do that. if nil,
+  ammo is infinite.
+
+default guns manage ammo and
+cooldown in shoot, then call
+actually_shoot to create the
+projectile. override only
+actually_shoot to change
+projectile logic while keeping
+cooldown and ammo logic.
+
+bullets
+-------
+* dx, dy - movement per frame.
+  player bullets use -dy
+  instead.
+* enemyspd - multiplier for dx
+  and dy on enemy bullets.
+  default is 0.5, making enemy
+  shots much easier to dodge
+* damage - damage per hit;
+  used by ships
+* sprite - sprite index.
+* x_off, y_off - renamed for
+  the next two vars. may revert
+* center_off_x - the horizontal
+  centerpoint of the bullet,
+  for positioning when firing.
+  assume a pixel's coordinates
+  refer to the upper left corner
+  of the pixel; the center of
+  a 2-width bullet with an
+  upper left corner at 0 is 1,
+  not 0.5.
+* top_off_y, bottom_off_y -
+  also for positioning when
+  firing. positive distance from
+  top or bottom edge to image.
+  top_off_y will usually be 0,
+  bottom_off_y will not be when
+  bullets are smaller than
+  the sprite box.
+* width, height - measured in
+  full sprites (8x8 boxes), not
+  pixels. used for drawing.
+
+bullets despawn when above or
+below the screen (player or
+enemy bullets, respectively).
+
+by default, bullets despawn
+when they hit something.
+override hitship to change this.
+
+ships
+____
+
+ships move by calculating
+momentum, then offsetting their
+position by that momentum, then
+clamping their position to the
+screen (horizontally only for
+ships that autoscroll). ships
+that autoscroll (slip==true)
+then slide down by scrollspeed.
+fractional coordinates are ok.
+after movement, ships lose
+momentum (ship.drag along each
+axis). abs(momentum) can't
+exceed ship.maxspeed.
+
+ships gain momentum by acting
+like a player pushing buttons.
+the player ship actually reads
+buttons for this.
+
+act -- returns new acceleration:
+dx, dy, shoot_spec, shoot_main.
+dx and dy are change in momentum
+in px/frame. this is controls
+only -- friction is handled in
+ship:move (`drag` value).
+
+ships hitting another ship take
+1 damage per frame of overlap.
+ships hitting a bullet check
+bullet.damage to find out how
+much damage they take. damage
+is applied to shields, then hp.
+damaged ships flash briefly -
+blue (12) if all damage was
+shielded, white (7) if hp was
+damaged. a ship that then has 0
+or less hp calls self:die() and
+tells the main game loop to
+remove it.
+
+shieldcooldown is the interval
+between restoring shield points.
+shieldpenalty is the delay
+before restoring points after
+any damage, reset to this value
+on every damaging hit (whether
+it is absorbed by the shield or
+not) -- shield behaves like
+halo and other shooters in its
+heritage, where it recovers if
+you avoid damage for a while.
+not that there is any safe cover
+in this kind of game.
+
+ships do not repair hp on their
+own. negative-damage bullets
+are treated as 0, but a bullet
+can choose to repair the ship
+it hits in its own hitship
+method, or otherwise edit it
+(changing weapons, refilling
+weapon ammo). powerups are
+therefore a kind of bullet.
+
+levels
+======
+
+a level is a table mapping
+effective frame number to
+functions. when a level starts,
+it sets lframe ("level frame")
+and distance to 0.
+
+every frame, level_frame
+increments lframe by 0x0.0001.
+then if the level is not frozen,
+it increments distance by 1.0
+and runs the function in the
+level table for exactly that
+frame number (if any). distance
+is therefore "nonfrozen frames",
+and is used to trigger level
+progress. lframe always
+increments. ships are encouraged
+to use lframe to control
+animation and movement, and may
+use distance to react to level
+progress separately from overall
+time. remember to multiply
+lframe-related stuff by 0x0001.
+
+a special sentinel value, eol,
+marks the end of the level.
+(the level engine doesn't know
+when it's out of events, so
+without eol, the level will
+simply have no events forever.)
+when it finds eol, level_frame
+throws away the current level
+and tells the main loop that it
+might be done. the main loop
+agrees the level is over and the
+player has won when the level
+has reached eol and there are
+no more enemy ships, enemy
+bullets, or background events
+remaining. player ships, player
+bullets, and intangibles are
+not counted.
+
+level freezing
+--------------
+the level is frozen when the
+global value freeze > 0.
+generally, something intending
+to block level progress (a
+miniboss, a minigame, etc.)
+increments freeze and prepares
+some means of decrementing it
+when it no longer wants to block
+level progress.
+
+most commonly, we want to block
+until some specific ship or
+group of ships has died. for
+these ships, override ship:die
+to decrement freeze. make sure
+to set ship.dead in any new
+ship:die method so anything else
+looking at it can recognize
+the ship as dead.
+
+for anything else, you probably
+want an event to figure out when
+to unfreeze.
+
+levels start at 1
+-----------------
+
+distance is initialized to 0
+but gets incremented before the
+first time the engine looks for
+events. therefore, the first
+frame of the level executes
+level[1]. since levelframe
+executes before anything else,
+level[1] sets up the first frame
+drawn in the level. the player
+does not see a blank world
+before level[1] runs.
+level[1] can therefore be used
+to reconfigure the player ship,
+set up backgrounds, start music,
+kick off some kind of fade-in
+animation, etc.
+
+
+events
+======
+the global list "events" stores
+0-argument functions which are
+called every frame. if they
+return true, they are removed
+from the list and not run again;
+if they return false, they stay
+and will be called in later
+frames. the level does not end
+while the events table is
+nonempty.
+
+events are most commonly used
+to set up something for later
+(for example, blip uses an event
+to remove the fx_pallete from
+the flashing ship when the blip
+expires), but can also be used
+to implement a "level within a
+level" that does something
+complicated until it's done. if
+you froze the level when
+creating the event, remember
+to thaw it (freeze -= 1) on all
+paths that return true.
+
+to do complex stuff in events,
+use a closure or a metatable
+that specifies __call.
+
+to avoid editing the events
+list while it is being iterated,
+events that create new events
+must add those events to
+new_events rather than events.
+new_events is only valid during
+the "event execution" stage, so
+events created at any other time
+must go directly on events
+without using new_events.
+
+intangibles
+===========
+
+the intangibles_fg and
+intangibles_bg lists contain
+items with :move and :draw.
+like ships and bullets, they
+move during _update60 and
+draw during _draw. they are
+not checked for collisions.
+
+intangibles_bg moves/draws
+before anything else moves or
+draws. intangibles_fg
+moves/draws last. this controls
+whether your intangible object
+draws in front of or behind
+other stuff. you probably want
+intangibles_bg for decorative
+elements and intangibles_fg
+for explosions, score popups,
+etc.
+
+there's no scrolling background
+engine but intangibles_bg could
+be used to create one, including
+using the map (otherwise unused
+in this engine) for the purpose.
+
+intangibles do not prevent the
+level from ending. like bullets
+and ships, if :move returns
+true, they are dropped.

rearm_prototype.p8

@@ -0,0 +1,223 @@
+pico-8 cartridge // http://www.pico-8.com
+version 42
+__lua__
+-- vacuum gambit
+-- by kistaro windrider
+
+-- stdlib
+
+-- generate standard "overlay"
+-- constructor for type tt.
+-- if tt.init is defined, generated
+-- new calls tt.init(ret) after
+-- 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)
+ local mt,oldnew,more = {__index=tt},tt.new,rawget(tt, "init")
+ tt.new=function(ret)
+  if(not ret) ret = {}
+  if(more) more(ret)
+  if(oldnew) oldnew(ret)
+  setmetatable(ret, mt)
+  return ret
+ end
+ return tt
+end
+
+function easeoutbounce(t)
+	local n1=7.5625
+	local d1=2.75
+
+	if (t<1/d1) then
+		return n1*t*t;
+	elseif(t<2/d1) then
+		t-=1.5/d1
+		return n1*t*t+.75;
+	elseif(t<2.5/d1) then
+		t-=2.25/d1
+		return n1*t*t+.9375;
+	else
+		t-=2.625/d1
+		return n1*t*t+.984375;
+	end
+end
+
+-->8
+-- entry points
+function _draw()
+ cls()
+ draw_hud_placeholder()
+ left_pane:draw()
+ right_pane:draw()
+ rearm_pane_instance:draw()
+end
+
+function _init()
+ item=1
+ bfm=1
+ crt_frm = 1
+ left_pane = weapon_pane.new{}
+ right_pane = weapon_pane.new{
+  is_left=false,
+  s = 2,
+  hdr = "vulc",
+  body = "   rate\n\n  faster\n  firing\n   rate",
+  hot = function() return item == 2 end}
+ rearm_pane_instance = rearm_pane.new{hot=function() return item < 0 end}
+end
+
+function _update60()
+ crt_frm += 0.25
+ if (crt_frm >= 9) crt_frm = 1
+ if (btn(3) and item > 0 or btn(2) and item < 0) item = -item
+ if (btn(0)) item = 1
+ if (btn(1)) item = 2
+ if (btn() & 0xF ~= 0) and bfm >= 10 or bfm >= 30 then
+  bfm = 1
+ else
+  bfm += 1
+ end
+
+ if btnp(4) then
+  left_pane.pos = -1
+  right_pane.pos = -1
+  rearm_pane_instance.pos = -1
+ end
+
+ if btnp(5) then 
+  left_pane.pos = 1
+  right_pane.pos = 1
+  rearm_pane_instance.pos = 1
+ end
+
+ left_pane:update()
+ right_pane:update()
+ rearm_pane_instance:update()
+end
+
+function draw_hud_placeholder()
+ rectfill(112, 0, 127, 127,0x56)
+ rect(112,0,127,127,7)
+ line(127,1,127,127,5)
+ line(113,127)
+end
+
+-->8
+-- rearm pane drawing
+
+crt={-91,-166,-2641,-1441,-23041,23295,-20491,24570}
+
+function glow_box(x0, y0, x1, y1, c, cf)
+ for i,v in ipairs{c[1],c[2],c[1],0} do
+  i -= 1
+  rect(x0+i,y0+i,x1-i,y1-i,v)
+ end
+ fillp(crt[crt_frm&0xff])
+ rectfill(x0+4, y0+4, x1-4, y1-4, cf)
+ fillp()
+end
+
+function frame_col(hot)
+ if (not hot) return {4,10}
+ if (bfm<=16) return {14,7}
+ return {2,8}
+end
+
+function draw_weap_opt(x, y, c, s, hdr, body)
+ camera(-x,-y)
+ glow_box(0,0,55,100,c,1)
+ spr(s,5, 5)
+ print(hdr, 13, 8, 7)
+ print(body, 5, 15, 6)
+ camera()
+end
+
+function draw_rearm(c)
+ glow_box(0,101,111,127,c,1)
+ spr(5,15,107,4,2)
+ print("full ammo\nfull shield\n+50% health",54, 106, 6)
+end
+
+-->8
+-- rearm pane objects
+easing_pane = mknew{
+ -- to enter: pos = -1; to exit: pos = 1
+ -- runs for 32 frames in, 16 frames out
+}
+
+function easing_pane:frac()
+ local pos = self.pos
+ if (not pos) return
+ if (pos < 0) return 1-easeoutbounce(1+pos)
+ if (pos > 0) return (1-pos)*(1-pos)
+ return 0
+end
+
+function easing_pane:update()
+ local pos = self.pos
+ if (not pos or pos == 0) return
+ if (pos < 0) pos = min(pos + 0x0.05, 0)
+ if pos > 0 then
+  pos -= 0x0.1
+  if (pos <= 0) pos = nil
+ end
+ self.pos = pos
+end
+
+weapon_pane = mknew(easing_pane.new{
+ is_left = true,
+ s = 1,
+ hdr = "hull",
+ body = "\n    +1\n   max\n  health",
+ hot = function() return item == 1 end,
+})
+
+function weapon_pane:draw()
+ local frac, is_left = self:frac(), self.is_left
+ if (not frac) return
+ camera(
+  frac * (is_left and 55 or -128) + (1-frac) * (is_left and 0 or -56),
+  0)
+ glow_box(0,0,55,100,frame_col(self:hot()),1)
+ spr(self.s,5, 5)
+ print(self.hdr, 13, 8, 7)
+ print(self.body, 5, 15, 6)
+ camera()
+end
+
+rearm_pane = mknew(easing_pane.new{})
+
+function rearm_pane:draw()
+ local frac = self:frac()
+ if (not frac) return
+ camera(0, -28 * frac)
+ glow_box(0,101,111,127,frame_col(self:hot()),1)
+ spr(5,15,107,4,2)
+ print("full ammo\nfull shield\n+50% health",54, 106, 6)
+ camera()
+end
+
+__gfx__
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+000000000008820000a0000008800880080aa080477777a00477777a000000000000000000000000000000000000000000000000000000000000000000000000
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+0000000000000000000000000000000000000000000000002e0002e02e002e02e02e02e000000000000000000000000000000000000000000000000000000000
+0000000000000000000000000000000000000000000000000e0000e00e000e00e00e00e000000000000000000000000000000000000000000000000000000000

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