From 08ac2f1125e9f0521b8347a56040223f3b2c0942 Mon Sep 17 00:00:00 2001
From: Orkuncakilkaya <orkuncakilkaya@gmail.com>
Date: Mon, 28 Sep 2026 00:10:56 +0300
Subject: [PATCH] ludic.ui: var() values found by their pieces,
 tpl_words/url/border-image by their text, nine-slices, picking, lifecycle,
 focus, hover, the event queue and input without a list or record made a frame

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
---
 packages/ludic.ui/attr.ludic          |  2 +-
 packages/ludic.ui/attr_edge.ludic     | 10 +--
 packages/ludic.ui/attr_more.ludic     |  4 +-
 packages/ludic.ui/backend.ludic       | 15 +++++
 packages/ludic.ui/color.ludic         |  6 +-
 packages/ludic.ui/draw_gradient.ludic | 10 +--
 packages/ludic.ui/draw_nine.ludic     |  6 +-
 packages/ludic.ui/focus.ludic         |  2 +-
 packages/ludic.ui/index.ludic         |  1 +
 packages/ludic.ui/input.ludic         | 32 ++++++++-
 packages/ludic.ui/instance.ludic      |  9 ++-
 packages/ludic.ui/life.ludic          | 28 ++++----
 packages/ludic.ui/memo.ludic          | 34 ++++++++++
 packages/ludic.ui/memo_join.ludic     |  3 +
 packages/ludic.ui/native.ludic        | 14 ++--
 packages/ludic.ui/pointer.ludic       |  4 +-
 packages/ludic.ui/pointer_pick.ludic  | 44 ++++++-------
 packages/ludic.ui/render3d_nine.ludic | 14 ++--
 packages/ludic.ui/text_fit.ludic      |  6 +-
 packages/ludic.ui/units.ludic         | 42 ++++++------
 packages/ludic.ui/units_pieces.ludic  | 93 +++++++++++++++++++++++++++
 21 files changed, 281 insertions(+), 98 deletions(-)
 create mode 100644 packages/ludic.ui/units_pieces.ludic

diff --git a/packages/ludic.ui/attr.ludic b/packages/ludic.ui/attr.ludic
index 7abacd78..162fb264 100644
--- a/packages/ludic.ui/attr.ludic
+++ b/packages/ludic.ui/attr.ludic
@@ -61,7 +61,7 @@ function el_look(ui_st: mut UiState, n: UiNode, key: string, v: Val) -> bool {
     n.fg = ui_color(ui_st, s)
     n.fg_a = ui_st.cl_alpha
   } else if key == "bg" {
-    if gr_is(tpl_words(s)) { nx(n).grad = gr_parse(ui_st, s) } else if len(s) > 4 and sat(s, 0, "url(") { n.bg_img = el_url(s) } else if tpl_words(s) == "transparent" {
+    if gr_is(tw(ui_st, s)) { nx(n).grad = gr_parse(ui_st, s) } else if len(s) > 4 and sat(s, 0, "url(") { n.bg_img = el_url_u(ui_st, s) } else if tw(ui_st, s) == "transparent" {
       n.bg = 0
       n.bg_a = 0.0
     } else {
diff --git a/packages/ludic.ui/attr_edge.ludic b/packages/ludic.ui/attr_edge.ludic
index 62df9758..416b80ac 100644
--- a/packages/ludic.ui/attr_edge.ludic
+++ b/packages/ludic.ui/attr_edge.ludic
@@ -8,7 +8,7 @@ function el_edge(ui_st: mut UiState, n: UiNode, key: string, v: Val) -> bool {
     let parts = mm_split(ui_st, s, 32)
     if len(parts) > 0 { n.bar_c = ui_color(ui_st, parts[0]) }
     if len(parts) > 1 { n.bar_track = ui_color(ui_st, parts[1]) }
-  } else if key == "background-image" and gr_is(tpl_words(s)) { nx(n).grad = gr_parse(ui_st, s) } else if key == "background-image" { n.bg_img = el_url(s) } else if key == "border-image" { el_border_image(ui_st, n, s) } else if key == "box-shadow" { el_shadow(ui_st, n, s) } else if key == "animation" { el_animation(ui_st, n, s) } else if key == "transition" { n.tr_dur = el_secs(s) } else { return false }
+  } else if key == "background-image" and gr_is(tw(ui_st, s)) { nx(n).grad = gr_parse(ui_st, s) } else if key == "background-image" { n.bg_img = el_url_u(ui_st, s) } else if key == "border-image" { el_border_image(ui_st, n, s) } else if key == "box-shadow" { el_shadow(ui_st, n, s) } else if key == "animation" { el_animation(ui_st, n, s) } else if key == "transition" { n.tr_dur = el_secs(s) } else { return false }
   return true
 }
 # url(path) or url("path") -> path
@@ -23,15 +23,15 @@ function el_url(s: string) -> string {
 function el_border_image(ui_st: mut UiState, n: UiNode, s: string) -> void {
   var close = 0
   while close < len(s) and s[close] != 41 { close += 1 }
-  n.bi_src = el_url(s[0..Math.min(close + 1, len(s))])
+  n.bi_src = el_url_u(ui_st, s[0..Math.min(close + 1, len(s))])
   let rest = mm_split(ui_st, s[Math.min(close + 1, len(s))..len(s)], 47)
-  n.bi_slice = el_num(tpl_words(rest[0]))
+  n.bi_slice = el_num(tw(ui_st, rest[0]))
   n.bi_width = el_px(ui_st, n.bi_slice)
-  if len(rest) > 1 { n.bi_width = el_unit(ui_st, tpl_words(rest[1])) }
+  if len(rest) > 1 { n.bi_width = el_unit(ui_st, tw(ui_st, rest[1])) }
 }
 # box-shadow: 6px 10px 0 rgba(0, 0, 0, 0.45)  - x, y, a blur this renderer draws sharp, the colour
 function el_shadow(ui_st: mut UiState, n: UiNode, s: string) -> void {
-  if tpl_words(s) == "none" {
+  if tw(ui_st, s) == "none" {
     n.sh_c = -2
     return
   }
diff --git a/packages/ludic.ui/attr_more.ludic b/packages/ludic.ui/attr_more.ludic
index bf00a328..efe5ade8 100644
--- a/packages/ludic.ui/attr_more.ludic
+++ b/packages/ludic.ui/attr_more.ludic
@@ -2,7 +2,7 @@
 # shorthand, flex-shrink, order, text-shadow, pointer-events, text-fit and line-height (text_fit.ludic)
 function el_more(ui_st: mut UiState, n: UiNode, key: string, v: Val) -> bool {
   let s = vl_text_u(ui_st, v)
-  if key == "shrink" { nx(n).shrink = Math.max(el_num(s), 0.0) } else if key == "order" { nx(n).order = int(el_num(s)) } else if key == "text-shadow" { el_text_shadow(ui_st, n, s) } else if key == "pointer-events" { nx(n).no_pointer = tpl_words(s) == "none" } else if key == "text-fit" { el_text_fit(ui_st, n, s) } else if key == "line-height" { el_line_h(ui_st, n, s) } else { return el_fit_props(ui_st, n, key, s) }
+  if key == "shrink" { nx(n).shrink = Math.max(el_num(s), 0.0) } else if key == "order" { nx(n).order = int(el_num(s)) } else if key == "text-shadow" { el_text_shadow(ui_st, n, s) } else if key == "pointer-events" { nx(n).no_pointer = tw(ui_st, s) == "none" } else if key == "text-fit" { el_text_fit(ui_st, n, s) } else if key == "line-height" { el_line_h(ui_st, n, s) } else { return el_fit_props(ui_st, n, key, s) }
   return true
 }
 # width or height: a length (0 included), fill, a percentage, calc(), or auto/fit (none)
@@ -71,7 +71,7 @@ function el_text_shadow(ui_st: mut UiState, n: UiNode, s: string) -> void {
   let x = nx(n)
   x.tsh_set = true
   x.tsh_c = -2
-  if tpl_words(s) == "none" { return }
+  if tw(ui_st, s) == "none" { return }
   let parts = mm_words(ui_st, s)
   var nums = 0
   var col = ""
diff --git a/packages/ludic.ui/backend.ludic b/packages/ludic.ui/backend.ludic
index 309256c3..879abe77 100644
--- a/packages/ludic.ui/backend.ludic
+++ b/packages/ludic.ui/backend.ludic
@@ -39,6 +39,12 @@ export state UiState {
   mm_ivals: []Val = null
   ev_depth: int = 0                      # eval.ludic: a call's arguments, in lists kept one a depth
   ev_args: []Val = new []Val
+  cv_texts: []string = new []string      # units_pieces.ludic: a value's var() pieces, kept
+  r3n_cut: []float = new []float         # render3d_nine.ludic: a nine-slice's edges, kept
+  r3n_xs: []float = new []float
+  r3n_ys: []float = new []float
+  r3n_us: []float = new []float
+  r3n_vs: []float = new []float
   ly_depth: int = 0                      # layout_run.ludic: the lists a line lays out with, one a depth
   ly_sizes: [][]float = new [][]float
   ly_frozen: [][]bool = new [][]bool
@@ -90,6 +96,8 @@ export state UiState {
   in_now: UiInput = new UiInput
   in_was_down: bool = false
   in_last: UiInput = new UiInput
+  in_rec_a: UiInput = new UiInput
+  in_rec_b: UiInput = new UiInput
   in_given: bool = false
   rp_next: []float = [-1.0, -1.0, -1.0, -1.0]
   rp_a: bool = false
@@ -109,14 +117,21 @@ export state UiState {
   lc_mounts: []UiAct = new []UiAct
   lc_unmounts: []UiAct = new []UiAct
   lc_envs: []UiEnv = new []UiEnv
+  lc_sp_keys: []string = new []string    # life.ludic: the spare set lc_run fills and swaps in
+  lc_sp_unmounts: []UiAct = new []UiAct
+  lc_sp_envs: []UiEnv = new []UiEnv
   lc_prev_keys: []string = new []string
   lc_prev_unmounts: []UiAct = new []UiAct
   lc_prev_envs: []UiEnv = new []UiEnv
   nt_list: []UiNative = new []UiNative
+  nt_sp_nodes: []UiNode = new []UiNode   # native.ludic: the queue's spare, swapped while it runs
+  nt_sp_names: []string = new []string
+  nt_sp_vals: []Val = new []Val
   nt_q_nodes: []UiNode = new []UiNode
   nt_q_names: []string = new []string
   nt_q_vals: []Val = new []Val
   fr_hover: []string = new []string
+  fr_hover_sp: []string = new []string
   fr_press_key: string = ""
   fr_down_now: bool = false
   fr_key_press: string = ""   # the control Enter or the pad's A is holding down
diff --git a/packages/ludic.ui/color.ludic b/packages/ludic.ui/color.ludic
index d3a462a2..a7b0a49e 100644
--- a/packages/ludic.ui/color.ludic
+++ b/packages/ludic.ui/color.ludic
@@ -2,7 +2,7 @@
 # basic names, transparent and none. A colour is 0xRRGGBB; its alpha is left in cl_alpha.
 const CL_NAMES: string = " black=000000 white=ffffff red=ff0000 green=008000 lime=00ff00 blue=0000ff yellow=ffff00 cyan=00ffff aqua=00ffff magenta=ff00ff fuchsia=ff00ff gray=808080 grey=808080 silver=c0c0c0 maroon=800000 olive=808000 navy=000080 purple=800080 teal=008080 orange=ffa500 "
 function ui_color(ui_st: mut UiState, name0: string) -> int {
-  let name = tpl_words(name0)
+  let name = tw(ui_st, name0)
   ui_st.cl_alpha = 1.0
   if name == "none" or name == "" or name == "transparent" { return UI_NONE }
   if name[0] == 35 { return cl_hex_at(ui_st, name, 1, len(name) - 1) }
@@ -38,8 +38,8 @@ function cl_rgb(ui_st: mut UiState, s: string) -> int {
   while open < len(s) and s[open] != 40 { open += 1 }
   let parts = mm_split(ui_st, s[open + 1..len(s) - 1], 44)
   var c = 0
-  for i in 0 .. Math.min(3, len(parts)) { c = c * 256 + Math.clamp(int(el_num(tpl_words(parts[i]))), 0, 255) }
-  if len(parts) > 3 { ui_st.cl_alpha = el_num(tpl_words(parts[3])) }
+  for i in 0 .. Math.min(3, len(parts)) { c = c * 256 + Math.clamp(int(el_num(tw(ui_st, parts[i]))), 0, 255) }
+  if len(parts) > 3 { ui_st.cl_alpha = el_num(tw(ui_st, parts[3])) }
   return c
 }
 # a colour as #rrggbb, for a dump or a test
diff --git a/packages/ludic.ui/draw_gradient.ludic b/packages/ludic.ui/draw_gradient.ludic
index 2bee4fff..c56f8bec 100644
--- a/packages/ludic.ui/draw_gradient.ludic
+++ b/packages/ludic.ui/draw_gradient.ludic
@@ -19,22 +19,22 @@ function gr_parse(ui_st: mut UiState, s0: string) -> UiGradient {
   return g
 }
 function gr_parse_new(ui_st: mut UiState, s0: string) -> UiGradient {
-  let s = tpl_words(s0)
+  let s = tw(ui_st, s0)
   let parts = el_commas(s[16..len(s) - 1])
   let g = new UiGradient
   g.cols = new []int
   g.alphas = new []float
   g.at = new []float
   var from = 0
-  if len(parts) > 0 and gr_dir(g, tpl_words(parts[0])) { from = 1 }
+  if len(parts) > 0 and gr_dir(g, tw(ui_st, parts[0])) { from = 1 }
   for i in from .. len(parts) {
-    let words = mm_words(ui_st, tpl_words(parts[i]))
-    var col = tpl_words(parts[i])
+    let words = mm_words(ui_st, tw(ui_st, parts[i]))
+    var col = tw(ui_st, parts[i])
     var at = -1.0
     let last = words[len(words) - 1]
     if len(words) > 1 and last[len(last) - 1] == 37 {
       at = el_num(last) / 100.0
-      col = tpl_words(col[0..len(col) - len(last)])
+      col = tw(ui_st, col[0..len(col) - len(last)])
     }
     push(g.cols, ui_color(ui_st, col))
     push(g.alphas, ui_st.cl_alpha)
diff --git a/packages/ludic.ui/draw_nine.ludic b/packages/ludic.ui/draw_nine.ludic
index 88b6425b..213702f6 100644
--- a/packages/ludic.ui/draw_nine.ludic
+++ b/packages/ludic.ui/draw_nine.ludic
@@ -2,10 +2,12 @@
 # more than half the box across or half of it down (each direction on its own, so a small key cap
 # keeps its round ends and has no seam), on whole pixels so the nine pieces meet exactly
 # x0 x1 x2 x3 then y0 y1 y2 y3: the columns' and the rows' edges
-export function ui_nine_cuts(x: float, y: float, w: float, h: float, dst: float) -> []float {
+export function ui_nine_cuts(x: float, y: float, w: float, h: float, dst: float) -> []float { return ui_nine_cuts_into(new []float, x, y, w, h, dst) }
+# the same into a list the caller keeps, emptied first
+function ui_nine_cuts_into(out: []float, x: float, y: float, w: float, h: float, dst: float) -> []float {
   let dx = Math.max(Math.min(dst, w / 2.0), 0.0)
   let dy = Math.max(Math.min(dst, h / 2.0), 0.0)
-  let out = new []float
+  List.clear(out)
   push(out, nn_px(x))
   push(out, nn_px(x + dx))
   push(out, nn_px(x + w - dx))
diff --git a/packages/ludic.ui/focus.ludic b/packages/ludic.ui/focus.ludic
index c73e6c25..e81b8eeb 100644
--- a/packages/ludic.ui/focus.ludic
+++ b/packages/ludic.ui/focus.ludic
@@ -23,7 +23,7 @@ function fc_move(ui_st: mut UiState, step: int) -> void {
 }
 # the keys, after the tree is laid out: moving, then acting on what has the focus
 function fc_keys(ui_st: mut UiState, root: UiNode) -> void {
-  ui_st.fc_list = new []UiNode
+  List.clear(ui_st.fc_list)
   let top = pp_top(root)
   if top != null { fc_collect(ui_st, top) } else { fc_collect(ui_st, root) }
   if ct_key_capture(ui_st, ui_st.fc_list) { return }
diff --git a/packages/ludic.ui/index.ludic b/packages/ludic.ui/index.ludic
index 788175b1..07401b9c 100644
--- a/packages/ludic.ui/index.ludic
+++ b/packages/ludic.ui/index.ludic
@@ -12,6 +12,7 @@ import "pool_reset.ludic"
 import "pool_reset_more.ludic"
 import "memo.ludic"
 import "memo_join.ludic"
+import "units_pieces.ludic"
 import "expr.ludic"
 import "expr_parse.ludic"
 import "expr_prim.ludic"
diff --git a/packages/ludic.ui/input.ludic b/packages/ludic.ui/input.ludic
index 5ab70f58..99cde3c0 100644
--- a/packages/ludic.ui/input.ludic
+++ b/packages/ludic.ui/input.ludic
@@ -34,8 +34,10 @@ function in_read(ui_st: mut UiState) -> void {
     return
   }
   ui_st.in_was_down = ui_st.in_now.down
+  var i = ui_st.in_rec_a                       # the package's own two records, in turn (never a host's)
+  if ui_st.in_now == ui_st.in_rec_a { i = ui_st.in_rec_b }
   ui_st.in_last = ui_st.in_now
-  let i = new UiInput
+  in_reset(i)
   if ui_st.ui_be != null and ui_st.ui_be.input {
     let ps = in_pointer_scale(ui_st)
     i.x = float(Input.mouse_x()) * ps
@@ -81,3 +83,31 @@ export function ui_input(ui_st: mut UiState, i: UiInput) -> void {
   ui_st.in_now = i
   ui_st.in_given = true
 }
+# every field back to its default (generated from UiInput)
+function in_reset(i: UiInput) -> void {
+  i.x = -1.0
+  i.y = -1.0
+  i.down = false
+  i.wheel = 0.0
+  i.tab = false
+  i.shift = false
+  i.up = false
+  i.down_key = false
+  i.left = false
+  i.right = false
+  i.enter = false
+  i.space = false
+  i.escape = false
+  i.backspace = false
+  i.typed = ""
+  i.key = 0
+  i.held_up = false
+  i.held_down = false
+  i.held_left = false
+  i.held_right = false
+  i.pad_a = false
+  i.pad_b = false
+  i.held_enter = false
+  i.down_right = false
+  i.down_middle = false
+}
diff --git a/packages/ludic.ui/instance.ludic b/packages/ludic.ui/instance.ludic
index 30bec83e..7ff46e8c 100644
--- a/packages/ludic.ui/instance.ludic
+++ b/packages/ludic.ui/instance.ludic
@@ -25,10 +25,13 @@ function in_get(ui_st: mut UiState, key: string, k: UiClass) -> UiInst {
 }
 # after a build of `screen`: its instances the build did not reach are unmounted
 function in_sweep(ui_st: mut UiState, screen: string) -> void {
-  let keep = new []UiInst
+  var kept = 0
   for i in 0 .. len(ui_st.in_list) {
     let it = ui_st.in_list[i]
-    if it.seen == ui_st.in_build or not lc_mine(it.key, screen) { push(keep, it) }
+    if it.seen == ui_st.in_build or not lc_mine(it.key, screen) {
+      ui_st.in_list[kept] = it
+      kept += 1
+    }
   }
-  ui_st.in_list = keep
+  while len(ui_st.in_list) > kept { List.pop(ui_st.in_list) }
 }
diff --git a/packages/ludic.ui/life.ludic b/packages/ludic.ui/life.ludic
index 611b920a..f1ac2651 100644
--- a/packages/ludic.ui/life.ludic
+++ b/packages/ludic.ui/life.ludic
@@ -2,10 +2,10 @@
 # in last frame is mounted, and one that is gone is unmounted, each once, after the frame is drawn
 # a build starts its own records: a screen built twice keeps only the last build's
 function lc_begin(ui_st: mut UiState) -> void {
-  ui_st.lc_keys = new []string
-  ui_st.lc_mounts = new []UiAct
-  ui_st.lc_unmounts = new []UiAct
-  ui_st.lc_envs = new []UiEnv
+  List.clear(ui_st.lc_keys)
+  List.clear(ui_st.lc_mounts)
+  List.clear(ui_st.lc_unmounts)
+  List.clear(ui_st.lc_envs)
 }
 function lc_note(ui_st: mut UiState, key: string, names: []string, acts: []UiAct, e: UiEnv) -> void {
   var m: UiAct = null
@@ -29,9 +29,12 @@ function lc_run(ui_st: mut UiState, screen: string) -> void {
   for i in 0 .. len(ui_st.lc_keys) {
     if ui_st.lc_mounts[i] != null and not sel_has(ui_st.lc_prev_keys, ui_st.lc_keys[i]) { act_run(ui_st, ui_st.lc_mounts[i], ui_st.lc_envs[i]) }
   }
-  let keys = new []string
-  let unmounts = new []UiAct
-  let envs = new []UiEnv
+  let keys = ui_st.lc_sp_keys                  # the spare set, emptied: the records carried over
+  let unmounts = ui_st.lc_sp_unmounts
+  let envs = ui_st.lc_sp_envs
+  List.clear(keys)
+  List.clear(unmounts)
+  List.clear(envs)
   for i in 0 .. len(ui_st.lc_prev_keys) {
     let k = ui_st.lc_prev_keys[i]
     if lc_mine(k, screen) {
@@ -47,11 +50,14 @@ function lc_run(ui_st: mut UiState, screen: string) -> void {
     push(unmounts, ui_st.lc_unmounts[i])
     push(envs, ui_st.lc_envs[i])
   }
+  ui_st.lc_sp_keys = ui_st.lc_prev_keys
+  ui_st.lc_sp_unmounts = ui_st.lc_prev_unmounts
+  ui_st.lc_sp_envs = ui_st.lc_prev_envs
   ui_st.lc_prev_keys = keys
   ui_st.lc_prev_unmounts = unmounts
   ui_st.lc_prev_envs = envs
-  ui_st.lc_keys = new []string
-  ui_st.lc_mounts = new []UiAct
-  ui_st.lc_unmounts = new []UiAct
-  ui_st.lc_envs = new []UiEnv
+  List.clear(ui_st.lc_keys)
+  List.clear(ui_st.lc_mounts)
+  List.clear(ui_st.lc_unmounts)
+  List.clear(ui_st.lc_envs)
 }
diff --git a/packages/ludic.ui/memo.ludic b/packages/ludic.ui/memo.ludic
index 0c00b1da..27f8a9d1 100644
--- a/packages/ludic.ui/memo.ludic
+++ b/packages/ludic.ui/memo.ludic
@@ -9,10 +9,17 @@ export property UiMemo {
   tags: []int = null               # what kind of result: a separator, or a kind below
   lists: [][]string = null
   grads: []UiGradient = null
+  texts: []string = null           # a text worked out from the key: tw, el_url
+  vals: []Val = null               # a Value made from it: cs_vars_in's
+  vtpls: []UiVarTpl = null
 }
 const MM_WORDS: int = -1           # el_words: spaces, a bracket's own kept
 const MM_GRAD: int = -2
 const MM_JOIN: int = -3            # keys[i] is the joined text itself
+const MM_TW: int = -4              # tpl_words
+const MM_URL: int = -5             # el_url
+const MM_VARS: int = -6            # cs_vars_in: keys[i] is the text with every var() put in
+const MM_VTPL: int = -7            # a value's var()s parsed (units_pieces.ludic)
 function mm_new() -> UiMemo {
   let m = new UiMemo
   m.slots = words(MM_CAP)
@@ -20,6 +27,9 @@ function mm_new() -> UiMemo {
   m.tags = new []int
   m.lists = new [][]string
   m.grads = new []UiGradient
+  m.texts = new []string
+  m.vals = new []Val
+  m.vtpls = new []UiVarTpl
   return m
 }
 function mm_of(ui_st: mut UiState) -> UiMemo {
@@ -51,6 +61,9 @@ function mm_add(m: UiMemo, tag: int, s: string) -> int {
   push(m.tags, tag)
   push(m.lists, null)
   push(m.grads, null)
+  push(m.texts, null)
+  push(m.vals, null)
+  push(m.vtpls, null)
   m.slots[at] = len(m.keys)
   return len(m.keys) - 1
 }
@@ -66,3 +79,24 @@ function mm_split(ui_st: mut UiState, s: string, c: int) -> []string {
   return parts
 }
 function mm_words(ui_st: mut UiState, s: string) -> []string { return mm_split(ui_st, s, MM_WORDS) }
+# tpl_words, made once per text (a clean one is its own answer, and nothing is kept for it)
+function tw(ui_st: mut UiState, s: string) -> string {
+  if tpl_clean(s) { return s }
+  let m = mm_of(ui_st)
+  let i = mm_find(m, MM_TW, s)
+  if i >= 0 { return m.texts[i] }
+  let t = tpl_words(s)
+  let j = mm_add(m, MM_TW, s)
+  if j >= 0 { m.texts[j] = t }
+  return t
+}
+# el_url, made once per text
+function el_url_u(ui_st: mut UiState, s: string) -> string {
+  let m = mm_of(ui_st)
+  let i = mm_find(m, MM_URL, s)
+  if i >= 0 { return m.texts[i] }
+  let t = el_url(s)
+  let j = mm_add(m, MM_URL, s)
+  if j >= 0 { m.texts[j] = t }
+  return t
+}
diff --git a/packages/ludic.ui/memo_join.ludic b/packages/ludic.ui/memo_join.ludic
index 6031be13..0ae8f27b 100644
--- a/packages/ludic.ui/memo_join.ludic
+++ b/packages/ludic.ui/memo_join.ludic
@@ -28,6 +28,9 @@ function mm_join(ui_st: mut UiState, a: string, sep: string, b: string) -> strin
   push(m.tags, MM_JOIN)
   push(m.lists, null)
   push(m.grads, null)
+  push(m.texts, null)
+  push(m.vals, null)
+  push(m.vtpls, null)
   m.slots[at] = len(m.keys)
   return k
 }
diff --git a/packages/ludic.ui/native.ludic b/packages/ludic.ui/native.ludic
index 374878ab..fede399b 100644
--- a/packages/ludic.ui/native.ludic
+++ b/packages/ludic.ui/native.ludic
@@ -39,9 +39,9 @@ function nt_find(ui_st: UiState, tag: string) -> UiNative {
   return null
 }
 function nt_fired_clear(ui_st: mut UiState) -> void {
-  ui_st.nt_q_nodes = new []UiNode
-  ui_st.nt_q_names = new []string
-  ui_st.nt_q_vals = new []Val
+  List.clear(ui_st.nt_q_nodes)
+  List.clear(ui_st.nt_q_names)
+  List.clear(ui_st.nt_q_vals)
 }
 export function ui_fire(ui_st: mut UiState, n: UiNode, name: string, value: Val) -> void {
   push(ui_st.nt_q_nodes, n)
@@ -49,11 +49,17 @@ export function ui_fire(ui_st: mut UiState, n: UiNode, name: string, value: Val)
   push(ui_st.nt_q_vals, value)
 }
 function nt_fired_run(ui_st: mut UiState) -> void {
-  let nodes = ui_st.nt_q_nodes
+  let nodes = ui_st.nt_q_nodes                 # run from these while what they fire goes to the spares
   let names = ui_st.nt_q_names
   let vals = ui_st.nt_q_vals
+  ui_st.nt_q_nodes = ui_st.nt_sp_nodes
+  ui_st.nt_q_names = ui_st.nt_sp_names
+  ui_st.nt_q_vals = ui_st.nt_sp_vals
   nt_fired_clear(ui_st)
   for i in 0 .. len(nodes) { nt_run(ui_st, nodes[i], names[i], vals[i]) }
+  ui_st.nt_sp_nodes = nodes
+  ui_st.nt_sp_names = names
+  ui_st.nt_sp_vals = vals
 }
 # the element's on-<name>, with `event` bound to what happened
 function nt_run(ui_st: mut UiState, n: UiNode, name: string, value: Val) -> void {
diff --git a/packages/ludic.ui/pointer.ludic b/packages/ludic.ui/pointer.ludic
index 92b36bcc..8e0a25b6 100644
--- a/packages/ludic.ui/pointer.ludic
+++ b/packages/ludic.ui/pointer.ludic
@@ -5,11 +5,13 @@ function fr_was_hovered(ui_st: UiState, key: string) -> bool { return sel_has(ui
 function fr_pointer(ui_st: mut UiState, root: UiNode) -> void {
   let i = ui_st.in_now
   ui_st.fr_down_now = i.down
-  let keys = new []string
+  let keys = ui_st.fr_hover_sp                 # the spare list, emptied; last frame's goes spare
+  List.clear(keys)
   let top = pp_top(root)
   var scope = root
   if top != null { scope = top }
   fr_under(scope, i.x, i.y, keys)
+  ui_st.fr_hover_sp = ui_st.fr_hover
   ui_st.fr_hover = keys
   if top != null and pp_pointer(ui_st, top) { return }
   if ui_st.sc_drag != "" or ct_key_mouse(ui_st, root) { return }
diff --git a/packages/ludic.ui/pointer_pick.ludic b/packages/ludic.ui/pointer_pick.ludic
index 54d48014..4692ba67 100644
--- a/packages/ludic.ui/pointer_pick.ludic
+++ b/packages/ludic.ui/pointer_pick.ludic
@@ -8,29 +8,11 @@ function fr_in(n: UiNode, px: float, py: float) -> bool {
   if n.ex != null and n.ex.no_pointer { return false }
   return px >= n.x and py >= n.y and px < n.x + n.cw and py < n.y + n.ch
 }
-# the nearest element that wants `kind`, out from the topmost one under the point
+# the nearest element that wants `kind`, out from the topmost one under the point: the children are
+# walked the other way from how they are painted (positioned ones by z-index, highest first, then
+# the flow, last first; a popover is on the top layer, not here), with no list made for it
 function fr_pick(n: UiNode, px: float, py: float, kind: int) -> UiNode {
-  let kids = fr_paint_rev(n)
-  for i in 0 .. len(kids) {
-    if fr_in(kids[i], px, py) {
-      let r = fr_pick(kids[i], px, py, kind)
-      if r != null { return r }
-      return fr_wants(n, kind)
-    }
-  }
-  return fr_wants(n, kind)
-}
-function fr_wants(n: UiNode, kind: int) -> UiNode {
-  if kind == PK_CONTROL and (n.focusable or n.act != null) { return n }
-  if kind == PK_POINTER and pe_wants(n, false) { return n }
-  if kind == PK_WHEEL and pe_wants(n, true) { return n }
-  return null
-}
-# the children the other way from how they are painted: positioned ones by z-index, highest first,
-# then the flow, last first; a popover is on the top layer, not here
-function fr_paint_rev(n: UiNode) -> []UiNode {
-  let out = new []UiNode
-  if n.children == null { return out }
+  if n.children == null { return fr_wants(n, kind) }
   var lo = 1000000
   var hi = -1000000
   for i in 0 .. len(n.children) {
@@ -45,15 +27,27 @@ function fr_paint_rev(n: UiNode) -> []UiNode {
     var i = len(n.children) - 1
     while i >= 0 {
       let c = n.children[i]
-      if c.pos != 0 and not c.popover and c.z == z { push(out, c) }
+      if c.pos != 0 and not c.popover and c.z == z and fr_in(c, px, py) { return fr_pick_in(n, c, px, py, kind) }
       i -= 1
     }
     z -= 1
   }
   var k = len(n.children) - 1
   while k >= 0 {
-    if n.children[k].pos == 0 and not n.children[k].popover { push(out, n.children[k]) }
+    let c = n.children[k]
+    if c.pos == 0 and not c.popover and fr_in(c, px, py) { return fr_pick_in(n, c, px, py, kind) }
     k -= 1
   }
-  return out
+  return fr_wants(n, kind)
+}
+function fr_pick_in(n: UiNode, c: UiNode, px: float, py: float, kind: int) -> UiNode {
+  let r = fr_pick(c, px, py, kind)
+  if r != null { return r }
+  return fr_wants(n, kind)
+}
+function fr_wants(n: UiNode, kind: int) -> UiNode {
+  if kind == PK_CONTROL and (n.focusable or n.act != null) { return n }
+  if kind == PK_POINTER and pe_wants(n, false) { return n }
+  if kind == PK_WHEEL and pe_wants(n, true) { return n }
+  return null
 }
diff --git a/packages/ludic.ui/render3d_nine.ludic b/packages/ludic.ui/render3d_nine.ludic
index 641aced6..60ce4b1f 100644
--- a/packages/ludic.ui/render3d_nine.ludic
+++ b/packages/ludic.ui/render3d_nine.ludic
@@ -8,11 +8,11 @@ function r3u_nine(render3d_st: mut Render3dState, ui_st: mut UiState, src: strin
   if t == 0 { return }
   let su = slice / float(Math.max(tex_width(render3d_st, t), 1))
   let sv = slice / float(Math.max(tex_height(render3d_st, t), 1))
-  let cut = ui_nine_cuts(x, y, w, h, dst)
-  let xs = r3u_four(cut[0], cut[1], cut[2], cut[3])
-  let ys = r3u_four(cut[4], cut[5], cut[6], cut[7])
-  let us = r3u_four(0.0, su, 1.0 - su, 1.0)
-  let vs = r3u_four(0.0, sv, 1.0 - sv, 1.0)
+  let cut = ui_nine_cuts_into(ui_st.r3n_cut, x, y, w, h, dst)
+  let xs = r3u_four(ui_st.r3n_xs, cut[0], cut[1], cut[2], cut[3])
+  let ys = r3u_four(ui_st.r3n_ys, cut[4], cut[5], cut[6], cut[7])
+  let us = r3u_four(ui_st.r3n_us, 0.0, su, 1.0 - su, 1.0)
+  let vs = r3u_four(ui_st.r3n_vs, 0.0, sv, 1.0 - sv, 1.0)
   for j in 0 .. 3 {
     for i in 0 .. 3 {
       let x0 = int(xs[i])
@@ -21,8 +21,8 @@ function r3u_nine(render3d_st: mut Render3dState, ui_st: mut UiState, src: strin
     }
   }
 }
-function r3u_four(a: float, b: float, c: float, d: float) -> []float {
-  let out = new []float
+function r3u_four(out: []float, a: float, b: float, c: float, d: float) -> []float {
+  List.clear(out)
   push(out, a)
   push(out, b)
   push(out, c)
diff --git a/packages/ludic.ui/text_fit.ludic b/packages/ludic.ui/text_fit.ludic
index 10408770..cdd2f98f 100644
--- a/packages/ludic.ui/text_fit.ludic
+++ b/packages/ludic.ui/text_fit.ludic
@@ -2,12 +2,12 @@
 # size, and cuts what still does not fit with an ellipsis; line-height (a multiple of the font size,
 # px or em) spaces a text's lines. Both are inherited, as font properties are.
 function el_text_fit(ui_st: mut UiState, n: UiNode, s: string) -> void {
-  let parts = mm_split(ui_st, tpl_words(s), 32)
+  let parts = mm_split(ui_st, tw(ui_st, s), 32)
   nx(n).fit_min = 0.0
   if len(parts) >= 2 and parts[0] == "shrink" { nx(n).fit_min = Math.max(el_unit(ui_st, parts[1]), 1.0) }
 }
-function el_line_h(ui_st: UiState, n: UiNode, s0: string) -> void {
-  let s = tpl_words(s0)
+function el_line_h(ui_st: mut UiState, n: UiNode, s0: string) -> void {
+  let s = tw(ui_st, s0)
   let x = nx(n)
   x.lh_kind = 0
   if s == "normal" or s == "" { return }
diff --git a/packages/ludic.ui/units.ludic b/packages/ludic.ui/units.ludic
index 1d9fbb7f..82209b2f 100644
--- a/packages/ludic.ui/units.ludic
+++ b/packages/ludic.ui/units.ludic
@@ -46,37 +46,31 @@ function cs_var(n: UiNode, name: string) -> string {
   }
   return null
 }
-# a value with var(--name) or var(--name, fallback) in it, with each replaced by what it names
+# a value with var(--name) or var(--name, fallback) in it, with each replaced by what it names. What
+# it becomes is found by its pieces - stretches of the value and each var's text - compared in place,
+# so a result seen before (every frame's, nearly always) is its kept Value, and nothing is built
 function cs_vars_in(ui_st: mut UiState, n: UiNode, v: Val) -> Val {
   if Value.kind(v) != 4 { return v }
   let s = Value.as_str(v)
-  var at = 0
-  var out = ""
-  var found = false
-  var i = 0
-  while i + 4 <= len(s) {
-    if sat(s, i, "var(") {
-      found = true
-      var j = i + 4
-      var depth = 1
-      while j < len(s) and depth > 0 {
-        if s[j] == 40 { depth += 1 }
-        if s[j] == 41 { depth -= 1 }
-        j += 1
-      }
-      out = out + s[at..i] + cs_var_ref(ui_st, n, s[i + 4..j - 1])
-      at = j
-      i = j
-    } else { i += 1 }
+  if not cv_pieces(ui_st, n, s) { return v }
+  let m = mm_of(ui_st)
+  var at = cv_hash(ui_st) & (MM_CAP - 1)
+  while m.slots[at] != 0 {
+    let i = m.slots[at] - 1
+    if m.tags[i] == MM_VARS and cv_same(ui_st, m.keys[i]) { return m.vals[i] }
+    at = (at + 1) & (MM_CAP - 1)
   }
-  if not found { return v }
-  return Value.str(tpl_words(out + s[at..len(s)]))
+  let raw = cv_join(ui_st)
+  let r = Value.str(tpl_words(raw))
+  let j = mm_add(m, MM_VARS, raw)
+  if j >= 0 { m.vals[j] = r }
+  return r
 }
 function cs_var_ref(ui_st: mut UiState, n: UiNode, inner: string) -> string {
   let parts = mm_split(ui_st, inner, 44)
-  let v = cs_var(n, tpl_words(parts[0]))
+  let v = cs_var(n, tw(ui_st, parts[0]))
   if v != null { return v }
-  if len(parts) > 1 { return tpl_words(inner[len(parts[0]) + 1..len(inner)]) }
-  ui_err(ui_st, `var({tpl_words(parts[0])}): no element here or above sets it`)
+  if len(parts) > 1 { return tw(ui_st, inner[len(parts[0]) + 1..len(inner)]) }
+  ui_err(ui_st, `var({tw(ui_st, parts[0])}): no element here or above sets it`)
   return ""
 }
diff --git a/packages/ludic.ui/units_pieces.ludic b/packages/ludic.ui/units_pieces.ludic
new file mode 100644
index 00000000..d829735b
--- /dev/null
+++ b/packages/ludic.ui/units_pieces.ludic
@@ -0,0 +1,93 @@
+# units_pieces.ludic - a value with var()s, parsed once by its text into its stretches, the names it
+# asks for and their fallbacks; each frame its pieces are those stretches and what the names hold
+# here, in a list kept on the state, hashed and compared against the memo without a copy
+export property UiVarTpl {
+  lits: []string = null          # the text around the var()s: one more than there are names
+  names: []string = null
+  falls: []string = null         # a var's fallback, or null
+}
+function cv_tpl(ui_st: mut UiState, s: string) -> UiVarTpl {
+  let m = mm_of(ui_st)
+  let i = mm_find(m, MM_VTPL, s)
+  if i >= 0 { return m.vtpls[i] }
+  let t = cv_parse(ui_st, s)
+  let j = mm_add(m, MM_VTPL, s)
+  if j >= 0 { m.vtpls[j] = t }
+  return t
+}
+function cv_parse(ui_st: mut UiState, s: string) -> UiVarTpl {
+  let t = new UiVarTpl
+  t.lits = new []string
+  t.names = new []string
+  t.falls = new []string
+  var at = 0
+  var i = 0
+  while i + 4 <= len(s) {
+    if sat(s, i, "var(") {
+      var j = i + 4
+      var depth = 1
+      while j < len(s) and depth > 0 {
+        if s[j] == 40 { depth += 1 }
+        if s[j] == 41 { depth -= 1 }
+        j += 1
+      }
+      push(t.lits, s[at..i])
+      let inner = s[i + 4..j - 1]
+      let parts = lss_split(inner, 44)
+      push(t.names, tpl_words(parts[0]))
+      if len(parts) > 1 { push(t.falls, tpl_words(inner[len(parts[0]) + 1..len(inner)])) } else { push(t.falls, null) }
+      at = j
+      i = j
+    } else { i += 1 }
+  }
+  push(t.lits, s[at..len(s)])
+  return t
+}
+# this element's pieces for `s` into cv_texts; false when it has no var() at all
+function cv_pieces(ui_st: mut UiState, n: UiNode, s: string) -> bool {
+  if not cv_has(s) { return false }
+  let t = cv_tpl(ui_st, s)
+  List.clear(ui_st.cv_texts)
+  for k in 0 .. len(t.names) {
+    push(ui_st.cv_texts, t.lits[k])
+    push(ui_st.cv_texts, cv_value(ui_st, n, t, k))
+  }
+  push(ui_st.cv_texts, t.lits[len(t.names)])
+  return true
+}
+function cv_has(s: string) -> bool {
+  for i in 0 .. len(s) - 3 {
+    if s[i] == 118 and sat(s, i, "var(") { return true }
+  }
+  return false
+}
+function cv_value(ui_st: mut UiState, n: UiNode, t: UiVarTpl, k: int) -> string {
+  let v = cs_var(n, t.names[k])
+  if v != null { return v }
+  if t.falls[k] != null { return t.falls[k] }
+  ui_err(ui_st, `var({t.names[k]}): no element here or above sets it`)
+  return ""
+}
+function cv_hash(ui_st: UiState) -> int {
+  var h = 216613626 ^ (MM_VARS & 255)
+  for p in 0 .. len(ui_st.cv_texts) {
+    let t = ui_st.cv_texts[p]
+    for i in 0 .. len(t) { h = ((h ^ t[i]) * 16777619) & 2147483647 }
+  }
+  return h
+}
+# the pieces, one after another, are exactly `k`
+function cv_same(ui_st: UiState, k: string) -> bool {
+  var at = 0
+  for p in 0 .. len(ui_st.cv_texts) {
+    let t = ui_st.cv_texts[p]
+    if not sat(k, at, t) { return false }
+    at += len(t)
+  }
+  return at == len(k)
+}
+function cv_join(ui_st: UiState) -> string {
+  var out = ""
+  for p in 0 .. len(ui_st.cv_texts) { out = out + ui_st.cv_texts[p] }
+  return out
+}