2423 - describe shape-shifting in html docs

1 files changed, 113 insertions, 124 deletions

diff --git a/html/edit/002-typing.mu.html b/html/edit/002-typing.mu.html
index 787e3a4e..c1f1128f 100644
--- a/html/edit/002-typing.mu.html
+++ b/html/edit/002-typing.mu.html
@@ -13,15 +13,15 @@
 pre { white-space: pre-wrap; font-family: monospace; color: #eeeeee; background-color: #080808; }
 body { font-family: monospace; color: #eeeeee; background-color: #080808; }
 * { font-size: 1.05em; }
+.muControl { color: #c0a020; }
 .muRecipe { color: #ff8700; }
-.muData { color: #ffff00; }
 .Special { color: #ff6060; }
-.muScenario { color: #00af00; }
+.muData { color: #ffff00; }
 .Comment { color: #9090ff; }
 .Constant { color: #00a0a0; }
 .SalientComment { color: #00ffff; }
 .Delimiter { color: #a04060; }
-.muControl { color: #c0a020; }
+.muScenario { color: #00af00; }
 -->
 </style>
 
@@ -37,27 +37,25 @@ body { font-family: monospace; color: #eeeeee; background-color: #080808; }
 
 <span class="Comment"># temporary main: interactive editor</span>
 <span class="Comment"># hit ctrl-c to exit</span>
-<span class="muRecipe">recipe!</span> main [
+<span class="muRecipe">recipe!</span> main text:address:array:character [
   <span class="Constant">local-scope</span>
-  text:address:array:character<span class="Special"> &lt;- </span><span class="Constant">next-ingredient</span>
+  <span class="Constant">load-ingredients</span>
   open-console
   editor:address:editor-data<span class="Special"> &lt;- </span>new-editor text, <span class="Constant">0/screen</span>, <span class="Constant">5/left</span>, <span class="Constant">45/right</span>
   editor-event-loop <span class="Constant">0/screen</span>, <span class="Constant">0/console</span>, editor
   close-console
 ]
 
-<span class="muRecipe">recipe</span> editor-event-loop [
+<span class="muRecipe">recipe</span> editor-event-loop screen:address:screen, console:address:console, editor:address:editor-data [
   <span class="Constant">local-scope</span>
-  screen:address<span class="Special"> &lt;- </span><span class="Constant">next-ingredient</span>
-  console:address<span class="Special"> &lt;- </span><span class="Constant">next-ingredient</span>
-  editor:address:editor-data<span class="Special"> &lt;- </span><span class="Constant">next-ingredient</span>
+  <span class="Constant">load-ingredients</span>
   <span class="Delimiter">{</span>
     <span class="Comment"># looping over each (keyboard or touch) event as it occurs</span>
 <span class="Constant">    +next-event</span>
     cursor-row:number<span class="Special"> &lt;- </span>get *editor, <span class="Constant">cursor-row:offset</span>
     cursor-column:number<span class="Special"> &lt;- </span>get *editor, <span class="Constant">cursor-column:offset</span>
     screen<span class="Special"> &lt;- </span>move-cursor screen, cursor-row, cursor-column
-    e:event, console:address, found?:boolean, quit?:boolean<span class="Special"> &lt;- </span>read-event console
+    e:event, console:address:console, found?:boolean, quit?:boolean<span class="Special"> &lt;- </span>read-event console
     <span class="muControl">loop-unless</span> found?
     <span class="muControl">break-if</span> quit?  <span class="Comment"># only in tests</span>
     trace <span class="Constant">10</span>, <span class="Constant">[app]</span>, <span class="Constant">[next-event]</span>
@@ -82,11 +80,9 @@ body { font-family: monospace; color: #eeeeee; background-color: #080808; }
 ]
 
 <span class="Comment"># process click, return if it was on current editor</span>
-<span class="muRecipe">recipe</span> move-cursor-in-editor [
+<span class="muRecipe">recipe</span> move-cursor-in-editor screen:address:screen, editor:address:editor-data, t:touch-event<span class="muRecipe"> -&gt; </span>in-focus?:boolean [
   <span class="Constant">local-scope</span>
-  screen:address<span class="Special"> &lt;- </span><span class="Constant">next-ingredient</span>
-  editor:address:editor-data<span class="Special"> &lt;- </span><span class="Constant">next-ingredient</span>
-  t:touch-event<span class="Special"> &lt;- </span><span class="Constant">next-ingredient</span>
+  <span class="Constant">load-ingredients</span>
   <span class="muControl">reply-unless</span> editor, <span class="Constant">0/false</span>
   click-row:number<span class="Special"> &lt;- </span>get t, <span class="Constant">row:offset</span>
   <span class="muControl">reply-unless</span> click-row, <span class="Constant">0/false</span>  <span class="Comment"># ignore clicks on 'menu'</span>
@@ -106,24 +102,19 @@ body { font-family: monospace; color: #eeeeee; background-color: #080808; }
   <span class="muControl">reply</span> <span class="Constant">1/true</span>
 ]
 
-<span class="Comment"># editor &lt;- snap-cursor screen:address, editor:address:editor-data, target-row:number, target-column:number</span>
-<span class="Comment">#</span>
 <span class="Comment"># Variant of 'render' that only moves the cursor (coordinates and</span>
 <span class="Comment"># before-cursor). If it's past the end of a line, it 'slides' it left. If it's</span>
 <span class="Comment"># past the last line it positions at end of last line.</span>
-<span class="muRecipe">recipe</span> snap-cursor [
+<span class="muRecipe">recipe</span> snap-cursor screen:address:screen, editor:address:editor-data, target-row:number, target-column:number<span class="muRecipe"> -&gt; </span>editor:address:editor-data [
   <span class="Constant">local-scope</span>
-  screen:address<span class="Special"> &lt;- </span><span class="Constant">next-ingredient</span>
-  editor:address:editor-data<span class="Special"> &lt;- </span><span class="Constant">next-ingredient</span>
-  target-row:number<span class="Special"> &lt;- </span><span class="Constant">next-ingredient</span>
-  target-column:number<span class="Special"> &lt;- </span><span class="Constant">next-ingredient</span>
-  <span class="muControl">reply-unless</span> editor, <span class="Constant">1/top</span>, editor/same-as-ingredient:<span class="Constant">1</span>
+  <span class="Constant">load-ingredients</span>
+  <span class="muControl">reply-unless</span> editor
   left:number<span class="Special"> &lt;- </span>get *editor, <span class="Constant">left:offset</span>
   right:number<span class="Special"> &lt;- </span>get *editor, <span class="Constant">right:offset</span>
   screen-height:number<span class="Special"> &lt;- </span>screen-height screen
   <span class="Comment"># count newlines until screen row</span>
-  curr:address:duplex-list<span class="Special"> &lt;- </span>get *editor, <span class="Constant">top-of-screen:offset</span>
-  prev:address:duplex-list<span class="Special"> &lt;- </span>copy curr  <span class="Comment"># just in case curr becomes null and we can't compute prev-duplex</span>
+  curr:address:duplex-list:character<span class="Special"> &lt;- </span>get *editor, <span class="Constant">top-of-screen:offset</span>
+  prev:address:duplex-list:character<span class="Special"> &lt;- </span>copy curr  <span class="Comment"># just in case curr becomes null and we can't compute prev-duplex</span>
   curr<span class="Special"> &lt;- </span>next-duplex curr
   row:number<span class="Special"> &lt;- </span>copy <span class="Constant">1/top</span>
   column:number<span class="Special"> &lt;- </span>copy left
@@ -131,7 +122,7 @@ body { font-family: monospace; color: #eeeeee; background-color: #080808; }
   *cursor-row<span class="Special"> &lt;- </span>copy target-row
   cursor-column:address:number<span class="Special"> &lt;- </span>get-address *editor, <span class="Constant">cursor-column:offset</span>
   *cursor-column<span class="Special"> &lt;- </span>copy target-column
-  before-cursor:address:address:duplex-list<span class="Special"> &lt;- </span>get-address *editor, <span class="Constant">before-cursor:offset</span>
+  before-cursor:address:address:duplex-list:character<span class="Special"> &lt;- </span>get-address *editor, <span class="Constant">before-cursor:offset</span>
   <span class="Delimiter">{</span>
 <span class="Constant">    +next-character</span>
     <span class="muControl">break-unless</span> curr
@@ -195,23 +186,20 @@ body { font-family: monospace; color: #eeeeee; background-color: #080808; }
     *cursor-column<span class="Special"> &lt;- </span>copy column
     *before-cursor<span class="Special"> &lt;- </span>copy prev
   <span class="Delimiter">}</span>
-  <span class="muControl">reply</span> editor/same-as-ingredient:<span class="Constant">1</span>
 ]
 
-<span class="Comment"># screen, editor, go-render?:boolean &lt;- handle-keyboard-event screen:address, editor:address:editor-data, e:event</span>
 <span class="Comment"># Process an event 'e' and try to minimally update the screen.</span>
 <span class="Comment"># Set 'go-render?' to true to indicate the caller must perform a non-minimal update.</span>
-<span class="muRecipe">recipe</span> handle-keyboard-event [
+<span class="muRecipe">recipe</span> handle-keyboard-event screen:address:screen, editor:address:editor-data, e:event<span class="muRecipe"> -&gt; </span>screen:address:screen, editor:address:editor-data, go-render?:boolean [
   <span class="Constant">local-scope</span>
-  screen:address<span class="Special"> &lt;- </span><span class="Constant">next-ingredient</span>
-  editor:address:editor-data<span class="Special"> &lt;- </span><span class="Constant">next-ingredient</span>
-  e:event<span class="Special"> &lt;- </span><span class="Constant">next-ingredient</span>
-  <span class="muControl">reply-unless</span> editor, screen/same-as-ingredient:<span class="Constant">0</span>, editor/same-as-ingredient:<span class="Constant">1</span>, <span class="Constant">0/no-more-render</span>
+  <span class="Constant">load-ingredients</span>
+  go-render?<span class="Special"> &lt;- </span>copy <span class="Constant">0/false</span>
+  <span class="muControl">reply-unless</span> editor
   screen-width:number<span class="Special"> &lt;- </span>screen-width screen
   screen-height:number<span class="Special"> &lt;- </span>screen-height screen
   left:number<span class="Special"> &lt;- </span>get *editor, <span class="Constant">left:offset</span>
   right:number<span class="Special"> &lt;- </span>get *editor, <span class="Constant">right:offset</span>
-  before-cursor:address:address:duplex-list<span class="Special"> &lt;- </span>get-address *editor, <span class="Constant">before-cursor:offset</span>
+  before-cursor:address:address:duplex-list:character<span class="Special"> &lt;- </span>get-address *editor, <span class="Constant">before-cursor:offset</span>
   cursor-row:address:number<span class="Special"> &lt;- </span>get-address *editor, <span class="Constant">cursor-row:offset</span>
   cursor-column:address:number<span class="Special"> &lt;- </span>get-address *editor, <span class="Constant">cursor-column:offset</span>
   save-row:number<span class="Special"> &lt;- </span>copy *cursor-row
@@ -225,27 +213,27 @@ body { font-family: monospace; color: #eeeeee; background-color: #080808; }
 <span class="Constant">    &lt;handle-special-character&gt;</span>
     <span class="Comment"># ignore any other special characters</span>
     regular-character?:boolean<span class="Special"> &lt;- </span>greater-or-equal *c, <span class="Constant">32/space</span>
-    <span class="muControl">reply-unless</span> regular-character?, screen/same-as-ingredient:<span class="Constant">0</span>, editor/same-as-ingredient:<span class="Constant">1</span>, <span class="Constant">0/no-more-render</span>
+    go-render?<span class="Special"> &lt;- </span>copy <span class="Constant">0/false</span>
+    <span class="muControl">reply-unless</span> regular-character?
     <span class="Comment"># otherwise type it in</span>
 <span class="Constant">    &lt;insert-character-begin&gt;</span>
     editor, screen, go-render?:boolean<span class="Special"> &lt;- </span>insert-at-cursor editor, *c, screen
 <span class="Constant">    &lt;insert-character-end&gt;</span>
-    <span class="muControl">reply</span> screen/same-as-ingredient:<span class="Constant">0</span>, editor/same-as-ingredient:<span class="Constant">1</span>, go-render?
+    <span class="muControl">reply</span>
   <span class="Delimiter">}</span>
   <span class="Comment"># special key to modify the text or move the cursor</span>
   k:address:number<span class="Special"> &lt;- </span>maybe-convert e:event, <span class="Constant">keycode:variant</span>
   assert k, <span class="Constant">[event was of unknown type; neither keyboard nor mouse]</span>
   <span class="Comment"># handlers for each special key will go here</span>
 <span class="Constant">  &lt;handle-special-key&gt;</span>
-  <span class="muControl">reply</span> screen/same-as-ingredient:<span class="Constant">0</span>, editor/same-as-ingredient:<span class="Constant">1</span>, <span class="Constant">1/go-render</span>
+  go-render?<span class="Special"> &lt;- </span>copy <span class="Constant">1/true</span>
+  <span class="muControl">reply</span>
 ]
 
-<span class="muRecipe">recipe</span> insert-at-cursor [
+<span class="muRecipe">recipe</span> insert-at-cursor editor:address:editor-data, c:character, screen:address:screen<span class="muRecipe"> -&gt; </span>editor:address:editor-data, screen:address:screen, go-render?:boolean [
   <span class="Constant">local-scope</span>
-  editor:address:editor-data<span class="Special"> &lt;- </span><span class="Constant">next-ingredient</span>
-  c:character<span class="Special"> &lt;- </span><span class="Constant">next-ingredient</span>
-  screen:address<span class="Special"> &lt;- </span><span class="Constant">next-ingredient</span>
-  before-cursor:address:address:duplex-list<span class="Special"> &lt;- </span>get-address *editor, <span class="Constant">before-cursor:offset</span>
+  <span class="Constant">load-ingredients</span>
+  before-cursor:address:address:duplex-list:character<span class="Special"> &lt;- </span>get-address *editor, <span class="Constant">before-cursor:offset</span>
   insert-duplex c, *before-cursor
   *before-cursor<span class="Special"> &lt;- </span>next-duplex *before-cursor
   cursor-row:address:number<span class="Special"> &lt;- </span>get-address *editor, <span class="Constant">cursor-row:offset</span>
@@ -260,7 +248,7 @@ body { font-family: monospace; color: #eeeeee; background-color: #080808; }
 <span class="Constant">  &lt;insert-character-special-case&gt;</span>
   <span class="Comment"># but mostly we'll just move the cursor right</span>
   *cursor-column<span class="Special"> &lt;- </span>add *cursor-column, <span class="Constant">1</span>
-  next:address:duplex-list<span class="Special"> &lt;- </span>next-duplex *before-cursor
+  next:address:duplex-list:character<span class="Special"> &lt;- </span>next-duplex *before-cursor
   <span class="Delimiter">{</span>
     <span class="Comment"># at end of all text? no need to scroll? just print the character and leave</span>
     at-end?:boolean<span class="Special"> &lt;- </span>equal next, <span class="Constant">0/null</span>
@@ -272,20 +260,22 @@ body { font-family: monospace; color: #eeeeee; background-color: #080808; }
     <span class="muControl">break-if</span> overflow?
     move-cursor screen, save-row, save-column
     print-character screen, c
-    <span class="muControl">reply</span> editor/same-as-ingredient:<span class="Constant">0</span>, screen/same-as-ingredient:<span class="Constant">2</span>, <span class="Constant">0/no-more-render</span>
+    go-render?<span class="Special"> &lt;- </span>copy <span class="Constant">0/false</span>
+    <span class="muControl">reply</span>
   <span class="Delimiter">}</span>
   <span class="Delimiter">{</span>
     <span class="Comment"># not at right margin? print the character and rest of line</span>
     <span class="muControl">break-unless</span> next
     at-right?:boolean<span class="Special"> &lt;- </span>greater-or-equal *cursor-column, screen-width
     <span class="muControl">break-if</span> at-right?
-    curr:address:duplex-list<span class="Special"> &lt;- </span>copy *before-cursor
+    curr:address:duplex-list:character<span class="Special"> &lt;- </span>copy *before-cursor
     move-cursor screen, save-row, save-column
     curr-column:number<span class="Special"> &lt;- </span>copy save-column
     <span class="Delimiter">{</span>
       <span class="Comment"># hit right margin? give up and let caller render</span>
+      go-render?<span class="Special"> &lt;- </span>copy <span class="Constant">1/true</span>
       at-right?:boolean<span class="Special"> &lt;- </span>greater-than curr-column, right
-      <span class="muControl">reply-if</span> at-right?, editor/same-as-ingredient:<span class="Constant">0</span>, screen/same-as-ingredient:<span class="Constant">2</span>, <span class="Constant">1/go-render</span>
+      <span class="muControl">reply-if</span> at-right?
       <span class="muControl">break-unless</span> curr
       <span class="Comment"># newline? done.</span>
       currc:character<span class="Special"> &lt;- </span>get *curr, <span class="Constant">value:offset</span>
@@ -296,16 +286,17 @@ body { font-family: monospace; color: #eeeeee; background-color: #080808; }
       curr<span class="Special"> &lt;- </span>next-duplex curr
       <span class="muControl">loop</span>
     <span class="Delimiter">}</span>
-    <span class="muControl">reply</span> editor/same-as-ingredient:<span class="Constant">0</span>, screen/same-as-ingredient:<span class="Constant">2</span>, <span class="Constant">0/no-more-render</span>
+    go-render?<span class="Special"> &lt;- </span>copy <span class="Constant">0/false</span>
+    <span class="muControl">reply</span>
   <span class="Delimiter">}</span>
-  <span class="muControl">reply</span> editor/same-as-ingredient:<span class="Constant">0</span>, screen/same-as-ingredient:<span class="Constant">2</span>, <span class="Constant">1/go-render</span>
+  go-render?<span class="Special"> &lt;- </span>copy <span class="Constant">1/true</span>
+  <span class="muControl">reply</span>
 ]
 
 <span class="Comment"># helper for tests</span>
-<span class="muRecipe">recipe</span> editor-render [
+<span class="muRecipe">recipe</span> editor-render screen:address:screen, editor:address:editor-data<span class="muRecipe"> -&gt; </span>screen:address:screen [
   <span class="Constant">local-scope</span>
-  screen:address<span class="Special"> &lt;- </span><span class="Constant">next-ingredient</span>
-  editor:address:editor-data<span class="Special"> &lt;- </span><span class="Constant">next-ingredient</span>
+  <span class="Constant">load-ingredients</span>
   left:number<span class="Special"> &lt;- </span>get *editor, <span class="Constant">left:offset</span>
   right:number<span class="Special"> &lt;- </span>get *editor, <span class="Constant">right:offset</span>
   row:number, column:number<span class="Special"> &lt;- </span>render screen, editor
@@ -319,11 +310,11 @@ body { font-family: monospace; color: #eeeeee; background-color: #080808; }
 <span class="muScenario">scenario</span> editor-handles-empty-event-queue [
   assume-screen <span class="Constant">10/width</span>, <span class="Constant">5/height</span>
   <span class="Constant">1</span>:address:array:character<span class="Special"> &lt;- </span>new <span class="Constant">[abc]</span>
-  <span class="Constant">2</span>:address:editor-data<span class="Special"> &lt;- </span>new-editor <span class="Constant">1</span>:address:array:character, screen:address, <span class="Constant">0/left</span>, <span class="Constant">10/right</span>
+  <span class="Constant">2</span>:address:editor-data<span class="Special"> &lt;- </span>new-editor <span class="Constant">1</span>:address:array:character, screen:address:screen, <span class="Constant">0/left</span>, <span class="Constant">10/right</span>
   editor-render screen, <span class="Constant">2</span>:address:editor-data
   assume-console <span class="Constant">[]</span>
   run [
-    editor-event-loop screen:address, console:address, <span class="Constant">2</span>:address:editor-data
+    editor-event-loop screen:address:screen, console:address:console, <span class="Constant">2</span>:address:editor-data
   ]
   screen-should-contain [
    <span class="Constant"> .          .</span>
@@ -336,14 +327,14 @@ body { font-family: monospace; color: #eeeeee; background-color: #080808; }
 <span class="muScenario">scenario</span> editor-handles-mouse-clicks [
   assume-screen <span class="Constant">10/width</span>, <span class="Constant">5/height</span>
   <span class="Constant">1</span>:address:array:character<span class="Special"> &lt;- </span>new <span class="Constant">[abc]</span>
-  <span class="Constant">2</span>:address:editor-data<span class="Special"> &lt;- </span>new-editor <span class="Constant">1</span>:address:array:character, screen:address, <span class="Constant">0/left</span>, <span class="Constant">10/right</span>
+  <span class="Constant">2</span>:address:editor-data<span class="Special"> &lt;- </span>new-editor <span class="Constant">1</span>:address:array:character, screen:address:screen, <span class="Constant">0/left</span>, <span class="Constant">10/right</span>
   editor-render screen, <span class="Constant">2</span>:address:editor-data
 <span class="Constant">  $clear-trace</span>
   assume-console [
     left-click <span class="Constant">1</span>, <span class="Constant">1</span>  <span class="Comment"># on the 'b'</span>
   ]
   run [
-    editor-event-loop screen:address, console:address, <span class="Constant">2</span>:address:editor-data
+    editor-event-loop screen:address:screen, console:address:console, <span class="Constant">2</span>:address:editor-data
     <span class="Constant">3</span>:number<span class="Special"> &lt;- </span>get *<span class="Constant">2</span>:address:editor-data, <span class="Constant">cursor-row:offset</span>
     <span class="Constant">4</span>:number<span class="Special"> &lt;- </span>get *<span class="Constant">2</span>:address:editor-data, <span class="Constant">cursor-column:offset</span>
   ]
@@ -363,13 +354,13 @@ body { font-family: monospace; color: #eeeeee; background-color: #080808; }
 <span class="muScenario">scenario</span> editor-handles-mouse-clicks-outside-text [
   assume-screen <span class="Constant">10/width</span>, <span class="Constant">5/height</span>
   <span class="Constant">1</span>:address:array:character<span class="Special"> &lt;- </span>new <span class="Constant">[abc]</span>
-  <span class="Constant">2</span>:address:editor-data<span class="Special"> &lt;- </span>new-editor <span class="Constant">1</span>:address:array:character, screen:address, <span class="Constant">0/left</span>, <span class="Constant">10/right</span>
+  <span class="Constant">2</span>:address:editor-data<span class="Special"> &lt;- </span>new-editor <span class="Constant">1</span>:address:array:character, screen:address:screen, <span class="Constant">0/left</span>, <span class="Constant">10/right</span>
 <span class="Constant">  $clear-trace</span>
   assume-console [
     left-click <span class="Constant">1</span>, <span class="Constant">7</span>  <span class="Comment"># last line, to the right of text</span>
   ]
   run [
-    editor-event-loop screen:address, console:address, <span class="Constant">2</span>:address:editor-data
+    editor-event-loop screen:address:screen, console:address:console, <span class="Constant">2</span>:address:editor-data
     <span class="Constant">3</span>:number<span class="Special"> &lt;- </span>get *<span class="Constant">2</span>:address:editor-data, <span class="Constant">cursor-row:offset</span>
     <span class="Constant">4</span>:number<span class="Special"> &lt;- </span>get *<span class="Constant">2</span>:address:editor-data, <span class="Constant">cursor-column:offset</span>
   ]
@@ -384,13 +375,13 @@ body { font-family: monospace; color: #eeeeee; background-color: #080808; }
   assume-screen <span class="Constant">10/width</span>, <span class="Constant">5/height</span>
   <span class="Constant">1</span>:address:array:character<span class="Special"> &lt;- </span>new <span class="Constant">[abc</span>
 <span class="Constant">def]</span>
-  <span class="Constant">2</span>:address:editor-data<span class="Special"> &lt;- </span>new-editor <span class="Constant">1</span>:address:array:character, screen:address, <span class="Constant">0/left</span>, <span class="Constant">10/right</span>
+  <span class="Constant">2</span>:address:editor-data<span class="Special"> &lt;- </span>new-editor <span class="Constant">1</span>:address:array:character, screen:address:screen, <span class="Constant">0/left</span>, <span class="Constant">10/right</span>
 <span class="Constant">  $clear-trace</span>
   assume-console [
     left-click <span class="Constant">1</span>, <span class="Constant">7</span>  <span class="Comment"># interior line, to the right of text</span>
   ]
   run [
-    editor-event-loop screen:address, console:address, <span class="Constant">2</span>:address:editor-data
+    editor-event-loop screen:address:screen, console:address:console, <span class="Constant">2</span>:address:editor-data
     <span class="Constant">3</span>:number<span class="Special"> &lt;- </span>get *<span class="Constant">2</span>:address:editor-data, <span class="Constant">cursor-row:offset</span>
     <span class="Constant">4</span>:number<span class="Special"> &lt;- </span>get *<span class="Constant">2</span>:address:editor-data, <span class="Constant">cursor-column:offset</span>
   ]
@@ -405,13 +396,13 @@ body { font-family: monospace; color: #eeeeee; background-color: #080808; }
   assume-screen <span class="Constant">10/width</span>, <span class="Constant">5/height</span>
   <span class="Constant">1</span>:address:array:character<span class="Special"> &lt;- </span>new <span class="Constant">[abc</span>
 <span class="Constant">def]</span>
-  <span class="Constant">2</span>:address:editor-data<span class="Special"> &lt;- </span>new-editor <span class="Constant">1</span>:address:array:character, screen:address, <span class="Constant">0/left</span>, <span class="Constant">10/right</span>
+  <span class="Constant">2</span>:address:editor-data<span class="Special"> &lt;- </span>new-editor <span class="Constant">1</span>:address:array:character, screen:address:screen, <span class="Constant">0/left</span>, <span class="Constant">10/right</span>
 <span class="Constant">  $clear-trace</span>
   assume-console [
     left-click <span class="Constant">3</span>, <span class="Constant">7</span>  <span class="Comment"># below text</span>
   ]
   run [
-    editor-event-loop screen:address, console:address, <span class="Constant">2</span>:address:editor-data
+    editor-event-loop screen:address:screen, console:address:console, <span class="Constant">2</span>:address:editor-data
     <span class="Constant">3</span>:number<span class="Special"> &lt;- </span>get *<span class="Constant">2</span>:address:editor-data, <span class="Constant">cursor-row:offset</span>
     <span class="Constant">4</span>:number<span class="Special"> &lt;- </span>get *<span class="Constant">2</span>:address:editor-data, <span class="Constant">cursor-column:offset</span>
   ]
@@ -426,7 +417,7 @@ body { font-family: monospace; color: #eeeeee; background-color: #080808; }
   assume-screen <span class="Constant">10/width</span>, <span class="Constant">5/height</span>
   <span class="Constant">1</span>:address:array:character<span class="Special"> &lt;- </span>new <span class="Constant">[abc]</span>
   <span class="Comment"># editor occupies only left half of screen</span>
-  <span class="Constant">2</span>:address:editor-data<span class="Special"> &lt;- </span>new-editor <span class="Constant">1</span>:address:array:character, screen:address, <span class="Constant">0/left</span>, <span class="Constant">5/right</span>
+  <span class="Constant">2</span>:address:editor-data<span class="Special"> &lt;- </span>new-editor <span class="Constant">1</span>:address:array:character, screen:address:screen, <span class="Constant">0/left</span>, <span class="Constant">5/right</span>
   editor-render screen, <span class="Constant">2</span>:address:editor-data
 <span class="Constant">  $clear-trace</span>
   assume-console [
@@ -434,7 +425,7 @@ body { font-family: monospace; color: #eeeeee; background-color: #080808; }
     left-click <span class="Constant">3</span>, <span class="Constant">8</span>
   ]
   run [
-    editor-event-loop screen:address, console:address, <span class="Constant">2</span>:address:editor-data
+    editor-event-loop screen:address:screen, console:address:console, <span class="Constant">2</span>:address:editor-data
     <span class="Constant">3</span>:number<span class="Special"> &lt;- </span>get *<span class="Constant">2</span>:address:editor-data, <span class="Constant">cursor-row:offset</span>
     <span class="Constant">4</span>:number<span class="Special"> &lt;- </span>get *<span class="Constant">2</span>:address:editor-data, <span class="Constant">cursor-column:offset</span>
   ]
@@ -454,7 +445,7 @@ body { font-family: monospace; color: #eeeeee; background-color: #080808; }
 <span class="muScenario">scenario</span> editor-handles-mouse-clicks-in-menu-area [
   assume-screen <span class="Constant">10/width</span>, <span class="Constant">5/height</span>
   <span class="Constant">1</span>:address:array:character<span class="Special"> &lt;- </span>new <span class="Constant">[abc]</span>
-  <span class="Constant">2</span>:address:editor-data<span class="Special"> &lt;- </span>new-editor <span class="Constant">1</span>:address:array:character, screen:address, <span class="Constant">0/left</span>, <span class="Constant">5/right</span>
+  <span class="Constant">2</span>:address:editor-data<span class="Special"> &lt;- </span>new-editor <span class="Constant">1</span>:address:array:character, screen:address:screen, <span class="Constant">0/left</span>, <span class="Constant">5/right</span>
   editor-render screen, <span class="Constant">2</span>:address:editor-data
 <span class="Constant">  $clear-trace</span>
   assume-console [
@@ -462,7 +453,7 @@ body { font-family: monospace; color: #eeeeee; background-color: #080808; }
     left-click <span class="Constant">0</span>, <span class="Constant">3</span>
   ]
   run [
-    editor-event-loop screen:address, console:address, <span class="Constant">2</span>:address:editor-data
+    editor-event-loop screen:address:screen, console:address:console, <span class="Constant">2</span>:address:editor-data
     <span class="Constant">3</span>:number<span class="Special"> &lt;- </span>get *<span class="Constant">2</span>:address:editor-data, <span class="Constant">cursor-row:offset</span>
     <span class="Constant">4</span>:number<span class="Special"> &lt;- </span>get *<span class="Constant">2</span>:address:editor-data, <span class="Constant">cursor-column:offset</span>
   ]
@@ -476,14 +467,14 @@ body { font-family: monospace; color: #eeeeee; background-color: #080808; }
 <span class="muScenario">scenario</span> editor-inserts-characters-into-empty-editor [
   assume-screen <span class="Constant">10/width</span>, <span class="Constant">5/height</span>
   <span class="Constant">1</span>:address:array:character<span class="Special"> &lt;- </span>new <span class="Constant">[]</span>
-  <span class="Constant">2</span>:address:editor-data<span class="Special"> &lt;- </span>new-editor <span class="Constant">1</span>:address:array:character, screen:address, <span class="Constant">0/left</span>, <span class="Constant">5/right</span>
+  <span class="Constant">2</span>:address:editor-data<span class="Special"> &lt;- </span>new-editor <span class="Constant">1</span>:address:array:character, screen:address:screen, <span class="Constant">0/left</span>, <span class="Constant">5/right</span>
   editor-render screen, <span class="Constant">2</span>:address:editor-data
 <span class="Constant">  $clear-trace</span>
   assume-console [
     type <span class="Constant">[abc]</span>
   ]
   run [
-    editor-event-loop screen:address, console:address, <span class="Constant">2</span>:address:editor-data
+    editor-event-loop screen:address:screen, console:address:console, <span class="Constant">2</span>:address:editor-data
   ]
   screen-should-contain [
    <span class="Constant"> .          .</span>
@@ -497,7 +488,7 @@ body { font-family: monospace; color: #eeeeee; background-color: #080808; }
 <span class="muScenario">scenario</span> editor-inserts-characters-at-cursor [
   assume-screen <span class="Constant">10/width</span>, <span class="Constant">5/height</span>
   <span class="Constant">1</span>:address:array:character<span class="Special"> &lt;- </span>new <span class="Constant">[abc]</span>
-  <span class="Constant">2</span>:address:editor-data<span class="Special"> &lt;- </span>new-editor <span class="Constant">1</span>:address:array:character, screen:address, <span class="Constant">0/left</span>, <span class="Constant">10/right</span>
+  <span class="Constant">2</span>:address:editor-data<span class="Special"> &lt;- </span>new-editor <span class="Constant">1</span>:address:array:character, screen:address:screen, <span class="Constant">0/left</span>, <span class="Constant">10/right</span>
   editor-render screen, <span class="Constant">2</span>:address:editor-data
 <span class="Constant">  $clear-trace</span>
   <span class="Comment"># type two letters at different places</span>
@@ -507,7 +498,7 @@ body { font-family: monospace; color: #eeeeee; background-color: #080808; }
     type <span class="Constant">[d]</span>
   ]
   run [
-    editor-event-loop screen:address, console:address, <span class="Constant">2</span>:address:editor-data
+    editor-event-loop screen:address:screen, console:address:console, <span class="Constant">2</span>:address:editor-data
   ]
   screen-should-contain [
    <span class="Constant"> .          .</span>
@@ -521,7 +512,7 @@ body { font-family: monospace; color: #eeeeee; background-color: #080808; }
 <span class="muScenario">scenario</span> editor-inserts-characters-at-cursor-2 [
   assume-screen <span class="Constant">10/width</span>, <span class="Constant">5/height</span>
   <span class="Constant">1</span>:address:array:character<span class="Special"> &lt;- </span>new <span class="Constant">[abc]</span>
-  <span class="Constant">2</span>:address:editor-data<span class="Special"> &lt;- </span>new-editor <span class="Constant">1</span>:address:array:character, screen:address, <span class="Constant">0/left</span>, <span class="Constant">10/right</span>
+  <span class="Constant">2</span>:address:editor-data<span class="Special"> &lt;- </span>new-editor <span class="Constant">1</span>:address:array:character, screen:address:screen, <span class="Constant">0/left</span>, <span class="Constant">10/right</span>
   editor-render screen, <span class="Constant">2</span>:address:editor-data
 <span class="Constant">  $clear-trace</span>
   assume-console [
@@ -529,7 +520,7 @@ body { font-family: monospace; color: #eeeeee; background-color: #080808; }
     type <span class="Constant">[d]</span>
   ]
   run [
-    editor-event-loop screen:address, console:address, <span class="Constant">2</span>:address:editor-data
+    editor-event-loop screen:address:screen, console:address:console, <span class="Constant">2</span>:address:editor-data
   ]
   screen-should-contain [
    <span class="Constant"> .          .</span>
@@ -544,7 +535,7 @@ body { font-family: monospace; color: #eeeeee; background-color: #080808; }
   assume-screen <span class="Constant">10/width</span>, <span class="Constant">5/height</span>
   <span class="Constant">1</span>:address:array:character<span class="Special"> &lt;- </span>new <span class="Constant">[abc</span>
 <span class="Constant">d]</span>
-  <span class="Constant">2</span>:address:editor-data<span class="Special"> &lt;- </span>new-editor <span class="Constant">1</span>:address:array:character, screen:address, <span class="Constant">0/left</span>, <span class="Constant">10/right</span>
+  <span class="Constant">2</span>:address:editor-data<span class="Special"> &lt;- </span>new-editor <span class="Constant">1</span>:address:array:character, screen:address:screen, <span class="Constant">0/left</span>, <span class="Constant">10/right</span>
   editor-render screen, <span class="Constant">2</span>:address:editor-data
 <span class="Constant">  $clear-trace</span>
   assume-console [
@@ -552,7 +543,7 @@ body { font-family: monospace; color: #eeeeee; background-color: #080808; }
     type <span class="Constant">[e]</span>
   ]
   run [
-    editor-event-loop screen:address, console:address, <span class="Constant">2</span>:address:editor-data
+    editor-event-loop screen:address:screen, console:address:console, <span class="Constant">2</span>:address:editor-data
   ]
   screen-should-contain [
    <span class="Constant"> .          .</span>
@@ -567,7 +558,7 @@ body { font-family: monospace; color: #eeeeee; background-color: #080808; }
 <span class="muScenario">scenario</span> editor-inserts-characters-at-cursor-3 [
   assume-screen <span class="Constant">10/width</span>, <span class="Constant">5/height</span>
   <span class="Constant">1</span>:address:array:character<span class="Special"> &lt;- </span>new <span class="Constant">[abc]</span>
-  <span class="Constant">2</span>:address:editor-data<span class="Special"> &lt;- </span>new-editor <span class="Constant">1</span>:address:array:character, screen:address, <span class="Constant">0/left</span>, <span class="Constant">10/right</span>
+  <span class="Constant">2</span>:address:editor-data<span class="Special"> &lt;- </span>new-editor <span class="Constant">1</span>:address:array:character, screen:address:screen, <span class="Constant">0/left</span>, <span class="Constant">10/right</span>
   editor-render screen, <span class="Constant">2</span>:address:editor-data
 <span class="Constant">  $clear-trace</span>
   assume-console [
@@ -575,7 +566,7 @@ body { font-family: monospace; color: #eeeeee; background-color: #080808; }
     type <span class="Constant">[d]</span>
   ]
   run [
-    editor-event-loop screen:address, console:address, <span class="Constant">2</span>:address:editor-data
+    editor-event-loop screen:address:screen, console:address:console, <span class="Constant">2</span>:address:editor-data
   ]
   screen-should-contain [
    <span class="Constant"> .          .</span>
@@ -590,7 +581,7 @@ body { font-family: monospace; color: #eeeeee; background-color: #080808; }
   assume-screen <span class="Constant">10/width</span>, <span class="Constant">5/height</span>
   <span class="Constant">1</span>:address:array:character<span class="Special"> &lt;- </span>new <span class="Constant">[abc</span>
 <span class="Constant">d]</span>
-  <span class="Constant">2</span>:address:editor-data<span class="Special"> &lt;- </span>new-editor <span class="Constant">1</span>:address:array:character, screen:address, <span class="Constant">0/left</span>, <span class="Constant">10/right</span>
+  <span class="Constant">2</span>:address:editor-data<span class="Special"> &lt;- </span>new-editor <span class="Constant">1</span>:address:array:character, screen:address:screen, <span class="Constant">0/left</span>, <span class="Constant">10/right</span>
   editor-render screen, <span class="Constant">2</span>:address:editor-data
 <span class="Constant">  $clear-trace</span>
   assume-console [
@@ -598,7 +589,7 @@ body { font-family: monospace; color: #eeeeee; background-color: #080808; }
     type <span class="Constant">[e]</span>
   ]
   run [
-    editor-event-loop screen:address, console:address, <span class="Constant">2</span>:address:editor-data
+    editor-event-loop screen:address:screen, console:address:console, <span class="Constant">2</span>:address:editor-data
   ]
   screen-should-contain [
    <span class="Constant"> .          .</span>
@@ -614,7 +605,7 @@ body { font-family: monospace; color: #eeeeee; background-color: #080808; }
   assume-screen <span class="Constant">10/width</span>, <span class="Constant">5/height</span>
   <span class="Constant">1</span>:address:array:character<span class="Special"> &lt;- </span>new <span class="Constant">[abc</span>
 <span class="Constant">d]</span>
-  <span class="Constant">2</span>:address:editor-data<span class="Special"> &lt;- </span>new-editor <span class="Constant">1</span>:address:array:character, screen:address, <span class="Constant">0/left</span>, <span class="Constant">10/right</span>
+  <span class="Constant">2</span>:address:editor-data<span class="Special"> &lt;- </span>new-editor <span class="Constant">1</span>:address:array:character, screen:address:screen, <span class="Constant">0/left</span>, <span class="Constant">10/right</span>
   editor-render screen, <span class="Constant">2</span>:address:editor-data
 <span class="Constant">  $clear-trace</span>
   assume-console [
@@ -622,7 +613,7 @@ body { font-family: monospace; color: #eeeeee; background-color: #080808; }
     type <span class="Constant">[ef]</span>
   ]
   run [
-    editor-event-loop screen:address, console:address, <span class="Constant">2</span>:address:editor-data
+    editor-event-loop screen:address:screen, console:address:console, <span class="Constant">2</span>:address:editor-data
   ]
   screen-should-contain [
    <span class="Constant"> .          .</span>
@@ -637,13 +628,13 @@ body { font-family: monospace; color: #eeeeee; background-color: #080808; }
 <span class="muScenario">scenario</span> editor-moves-cursor-after-inserting-characters [
   assume-screen <span class="Constant">10/width</span>, <span class="Constant">5/height</span>
   <span class="Constant">1</span>:address:array:character<span class="Special"> &lt;- </span>new <span class="Constant">[ab]</span>
-  <span class="Constant">2</span>:address:editor-data<span class="Special"> &lt;- </span>new-editor <span class="Constant">1</span>:address:array:character, screen:address, <span class="Constant">0/left</span>, <span class="Constant">5/right</span>
+  <span class="Constant">2</span>:address:editor-data<span class="Special"> &lt;- </span>new-editor <span class="Constant">1</span>:address:array:character, screen:address:screen, <span class="Constant">0/left</span>, <span class="Constant">5/right</span>
   editor-render screen, <span class="Constant">2</span>:address:editor-data
   assume-console [
     type <span class="Constant">[01]</span>
   ]
   run [
-    editor-event-loop screen:address, console:address, <span class="Constant">2</span>:address:editor-data
+    editor-event-loop screen:address:screen, console:address:console, <span class="Constant">2</span>:address:editor-data
   ]
   screen-should-contain [
    <span class="Constant"> .          .</span>
@@ -658,14 +649,14 @@ body { font-family: monospace; color: #eeeeee; background-color: #080808; }
 <span class="muScenario">scenario</span> editor-wraps-line-on-insert [
   assume-screen <span class="Constant">5/width</span>, <span class="Constant">5/height</span>
   <span class="Constant">1</span>:address:array:character<span class="Special"> &lt;- </span>new <span class="Constant">[abc]</span>
-  <span class="Constant">2</span>:address:editor-data<span class="Special"> &lt;- </span>new-editor <span class="Constant">1</span>:address:array:character, screen:address, <span class="Constant">0/left</span>, <span class="Constant">5/right</span>
+  <span class="Constant">2</span>:address:editor-data<span class="Special"> &lt;- </span>new-editor <span class="Constant">1</span>:address:array:character, screen:address:screen, <span class="Constant">0/left</span>, <span class="Constant">5/right</span>
   editor-render screen, <span class="Constant">2</span>:address:editor-data
   <span class="Comment"># type a letter</span>
   assume-console [
     type <span class="Constant">[e]</span>
   ]
   run [
-    editor-event-loop screen:address, console:address, <span class="Constant">2</span>:address:editor-data
+    editor-event-loop screen:address:screen, console:address:console, <span class="Constant">2</span>:address:editor-data
   ]
   <span class="Comment"># no wrap yet</span>
   screen-should-contain [
@@ -680,7 +671,7 @@ body { font-family: monospace; color: #eeeeee; background-color: #080808; }
     type <span class="Constant">[f]</span>
   ]
   run [
-    editor-event-loop screen:address, console:address, <span class="Constant">2</span>:address:editor-data
+    editor-event-loop screen:address:screen, console:address:console, <span class="Constant">2</span>:address:editor-data
   ]
   <span class="Comment"># now wrap</span>
   screen-should-contain [
@@ -697,7 +688,7 @@ body { font-family: monospace; color: #eeeeee; background-color: #080808; }
   assume-screen <span class="Constant">10/width</span>, <span class="Constant">5/height</span>
   <span class="Constant">1</span>:address:array:character<span class="Special"> &lt;- </span>new <span class="Constant">[abcdefg</span>
 <span class="Constant">defg]</span>
-  <span class="Constant">2</span>:address:editor-data<span class="Special"> &lt;- </span>new-editor <span class="Constant">1</span>:address:array:character, screen:address, <span class="Constant">0/left</span>, <span class="Constant">5/right</span>
+  <span class="Constant">2</span>:address:editor-data<span class="Special"> &lt;- </span>new-editor <span class="Constant">1</span>:address:array:character, screen:address:screen, <span class="Constant">0/left</span>, <span class="Constant">5/right</span>
   editor-render screen, <span class="Constant">2</span>:address:editor-data
   <span class="Comment"># type more text at the start</span>
   assume-console [
@@ -705,7 +696,7 @@ body { font-family: monospace; color: #eeeeee; background-color: #080808; }
     type <span class="Constant">[abc]</span>
   ]
   run [
-    editor-event-loop screen:address, console:address, <span class="Constant">2</span>:address:editor-data
+    editor-event-loop screen:address:screen, console:address:console, <span class="Constant">2</span>:address:editor-data
     <span class="Constant">3</span>:number<span class="Special"> &lt;- </span>get *<span class="Constant">2</span>:address:editor-data, <span class="Constant">cursor-row:offset</span>
     <span class="Constant">4</span>:number<span class="Special"> &lt;- </span>get *<span class="Constant">2</span>:address:editor-data, <span class="Constant">cursor-column:offset</span>
   ]
@@ -740,20 +731,21 @@ body { font-family: monospace; color: #eeeeee; background-color: #080808; }
       <span class="muControl">break-unless</span> below-screen?
 <span class="Constant">      &lt;scroll-down&gt;</span>
     <span class="Delimiter">}</span>
-    <span class="muControl">reply</span> editor/same-as-ingredient:<span class="Constant">0</span>, screen/same-as-ingredient:<span class="Constant">2</span>, <span class="Constant">1/go-render</span>
+    go-render?<span class="Special"> &lt;- </span>copy <span class="Constant">1/true</span>
+    <span class="muControl">reply</span>
   <span class="Delimiter">}</span>
 ]
 
 <span class="muScenario">scenario</span> editor-wraps-cursor-after-inserting-characters [
   assume-screen <span class="Constant">10/width</span>, <span class="Constant">5/height</span>
   <span class="Constant">1</span>:address:array:character<span class="Special"> &lt;- </span>new <span class="Constant">[abcde]</span>
-  <span class="Constant">2</span>:address:editor-data<span class="Special"> &lt;- </span>new-editor <span class="Constant">1</span>:address:array:character, screen:address, <span class="Constant">0/left</span>, <span class="Constant">5/right</span>
+  <span class="Constant">2</span>:address:editor-data<span class="Special"> &lt;- </span>new-editor <span class="Constant">1</span>:address:array:character, screen:address:screen, <span class="Constant">0/left</span>, <span class="Constant">5/right</span>
   assume-console [
     left-click <span class="Constant">1</span>, <span class="Constant">4</span>  <span class="Comment"># line is full; no wrap icon yet</span>
     type <span class="Constant">[f]</span>
   ]
   run [
-    editor-event-loop screen:address, console:address, <span class="Constant">2</span>:address:editor-data
+    editor-event-loop screen:address:screen, console:address:console, <span class="Constant">2</span>:address:editor-data
     <span class="Constant">3</span>:number<span class="Special"> &lt;- </span>get *<span class="Constant">2</span>:address:editor-data, <span class="Constant">cursor-row:offset</span>
     <span class="Constant">4</span>:number<span class="Special"> &lt;- </span>get *<span class="Constant">2</span>:address:editor-data, <span class="Constant">cursor-column:offset</span>
   ]
@@ -773,13 +765,13 @@ body { font-family: monospace; color: #eeeeee; background-color: #080808; }
 <span class="muScenario">scenario</span> editor-wraps-cursor-after-inserting-characters-2 [
   assume-screen <span class="Constant">10/width</span>, <span class="Constant">5/height</span>
   <span class="Constant">1</span>:address:array:character<span class="Special"> &lt;- </span>new <span class="Constant">[abcde]</span>
-  <span class="Constant">2</span>:address:editor-data<span class="Special"> &lt;- </span>new-editor <span class="Constant">1</span>:address:array:character, screen:address, <span class="Constant">0/left</span>, <span class="Constant">5/right</span>
+  <span class="Constant">2</span>:address:editor-data<span class="Special"> &lt;- </span>new-editor <span class="Constant">1</span>:address:array:character, screen:address:screen, <span class="Constant">0/left</span>, <span class="Constant">5/right</span>
   assume-console [
     left-click <span class="Constant">1</span>, <span class="Constant">3</span>  <span class="Comment"># right before the wrap icon</span>
     type <span class="Constant">[f]</span>
   ]
   run [
-    editor-event-loop screen:address, console:address, <span class="Constant">2</span>:address:editor-data
+    editor-event-loop screen:address:screen, console:address:console, <span class="Constant">2</span>:address:editor-data
     <span class="Constant">3</span>:number<span class="Special"> &lt;- </span>get *<span class="Constant">2</span>:address:editor-data, <span class="Constant">cursor-row:offset</span>
     <span class="Constant">4</span>:number<span class="Special"> &lt;- </span>get *<span class="Constant">2</span>:address:editor-data, <span class="Constant">cursor-column:offset</span>
   ]
@@ -799,13 +791,13 @@ body { font-family: monospace; color: #eeeeee; background-color: #080808; }
 <span class="muScenario">scenario</span> editor-wraps-cursor-to-left-margin [
   assume-screen <span class="Constant">10/width</span>, <span class="Constant">5/height</span>
   <span class="Constant">1</span>:address:array:character<span class="Special"> &lt;- </span>new <span class="Constant">[abcde]</span>
-  <span class="Constant">2</span>:address:editor-data<span class="Special"> &lt;- </span>new-editor <span class="Constant">1</span>:address:array:character, screen:address, <span class="Constant">2/left</span>, <span class="Constant">7/right</span>
+  <span class="Constant">2</span>:address:editor-data<span class="Special"> &lt;- </span>new-editor <span class="Constant">1</span>:address:array:character, screen:address:screen, <span class="Constant">2/left</span>, <span class="Constant">7/right</span>
   assume-console [
     left-click <span class="Constant">1</span>, <span class="Constant">5</span>  <span class="Comment"># line is full; no wrap icon yet</span>
     type <span class="Constant">[01]</span>
   ]
   run [
-    editor-event-loop screen:address, console:address, <span class="Constant">2</span>:address:editor-data
+    editor-event-loop screen:address:screen, console:address:console, <span class="Constant">2</span>:address:editor-data
     <span class="Constant">3</span>:number<span class="Special"> &lt;- </span>get *<span class="Constant">2</span>:address:editor-data, <span class="Constant">cursor-row:offset</span>
     <span class="Constant">4</span>:number<span class="Special"> &lt;- </span>get *<span class="Constant">2</span>:address:editor-data, <span class="Constant">cursor-column:offset</span>
   ]
@@ -836,13 +828,13 @@ body { font-family: monospace; color: #eeeeee; background-color: #080808; }
 <span class="muScenario">scenario</span> editor-moves-cursor-down-after-inserting-newline [
   assume-screen <span class="Constant">10/width</span>, <span class="Constant">5/height</span>
   <span class="Constant">1</span>:address:array:character<span class="Special"> &lt;- </span>new <span class="Constant">[abc]</span>
-  <span class="Constant">2</span>:address:editor-data<span class="Special"> &lt;- </span>new-editor <span class="Constant">1</span>:address:array:character, screen:address, <span class="Constant">0/left</span>, <span class="Constant">10/right</span>
+  <span class="Constant">2</span>:address:editor-data<span class="Special"> &lt;- </span>new-editor <span class="Constant">1</span>:address:array:character, screen:address:screen, <span class="Constant">0/left</span>, <span class="Constant">10/right</span>
   assume-console [
     type <span class="Constant">[0</span>
 <span class="Constant">1]</span>
   ]
   run [
-    editor-event-loop screen:address, console:address, <span class="Constant">2</span>:address:editor-data
+    editor-event-loop screen:address:screen, console:address:console, <span class="Constant">2</span>:address:editor-data
   ]
   screen-should-contain [
    <span class="Constant"> .          .</span>
@@ -860,17 +852,17 @@ body { font-family: monospace; color: #eeeeee; background-color: #080808; }
 <span class="Constant">    &lt;insert-enter-begin&gt;</span>
     editor<span class="Special"> &lt;- </span>insert-new-line-and-indent editor, screen
 <span class="Constant">    &lt;insert-enter-end&gt;</span>
-    <span class="muControl">reply</span> screen/same-as-ingredient:<span class="Constant">0</span>, editor/same-as-ingredient:<span class="Constant">1</span>, <span class="Constant">1/go-render</span>
+    go-render?<span class="Special"> &lt;- </span>copy <span class="Constant">1/true</span>
+    <span class="muControl">reply</span>
   <span class="Delimiter">}</span>
 ]
 
-<span class="muRecipe">recipe</span> insert-new-line-and-indent [
+<span class="muRecipe">recipe</span> insert-new-line-and-indent editor:address:editor-data, screen:address:screen<span class="muRecipe"> -&gt; </span>editor:address:editor-data, screen:address:screen, go-render?:boolean [
   <span class="Constant">local-scope</span>
-  editor:address:editor-data<span class="Special"> &lt;- </span><span class="Constant">next-ingredient</span>
-  screen:address<span class="Special"> &lt;- </span><span class="Constant">next-ingredient</span>
+  <span class="Constant">load-ingredients</span>
   cursor-row:address:number<span class="Special"> &lt;- </span>get-address *editor, <span class="Constant">cursor-row:offset</span>
   cursor-column:address:number<span class="Special"> &lt;- </span>get-address *editor, <span class="Constant">cursor-column:offset</span>
-  before-cursor:address:address:duplex-list<span class="Special"> &lt;- </span>get-address *editor, <span class="Constant">before-cursor:offset</span>
+  before-cursor:address:address:duplex-list:character<span class="Special"> &lt;- </span>get-address *editor, <span class="Constant">before-cursor:offset</span>
   left:number<span class="Special"> &lt;- </span>get *editor, <span class="Constant">left:offset</span>
   right:number<span class="Special"> &lt;- </span>get *editor, <span class="Constant">right:offset</span>
   screen-height:number<span class="Special"> &lt;- </span>screen-height screen
@@ -884,13 +876,14 @@ body { font-family: monospace; color: #eeeeee; background-color: #080808; }
     below-screen?:boolean<span class="Special"> &lt;- </span>greater-or-equal *cursor-row, screen-height  <span class="Comment"># must be equal, never greater</span>
     <span class="muControl">break-unless</span> below-screen?
 <span class="Constant">    &lt;scroll-down&gt;</span>
+    go-render?<span class="Special"> &lt;- </span>copy <span class="Constant">1/true</span>
     *cursor-row<span class="Special"> &lt;- </span>subtract *cursor-row, <span class="Constant">1</span>  <span class="Comment"># bring back into screen range</span>
   <span class="Delimiter">}</span>
   <span class="Comment"># indent if necessary</span>
   indent?:boolean<span class="Special"> &lt;- </span>get *editor, <span class="Constant">indent?:offset</span>
-  <span class="muControl">reply-unless</span> indent?, editor/same-as-ingredient:<span class="Constant">0</span>, screen/same-as-ingredient:<span class="Constant">1</span>
-  d:address:duplex-list<span class="Special"> &lt;- </span>get *editor, <span class="Constant">data:offset</span>
-  end-of-previous-line:address:duplex-list<span class="Special"> &lt;- </span>prev-duplex *before-cursor
+  <span class="muControl">reply-unless</span> indent?
+  d:address:duplex-list:character<span class="Special"> &lt;- </span>get *editor, <span class="Constant">data:offset</span>
+  end-of-previous-line:address:duplex-list:character<span class="Special"> &lt;- </span>prev-duplex *before-cursor
   indent:number<span class="Special"> &lt;- </span>line-indent end-of-previous-line, d
   i:number<span class="Special"> &lt;- </span>copy <span class="Constant">0</span>
   <span class="Delimiter">{</span>
@@ -900,19 +893,17 @@ body { font-family: monospace; color: #eeeeee; background-color: #080808; }
     i<span class="Special"> &lt;- </span>add i, <span class="Constant">1</span>
     <span class="muControl">loop</span>
   <span class="Delimiter">}</span>
-  <span class="muControl">reply</span> editor/same-as-ingredient:<span class="Constant">0</span>, screen/same-as-ingredient:<span class="Constant">1</span>
 ]
 
 <span class="Comment"># takes a pointer 'curr' into the doubly-linked list and its sentinel, counts</span>
 <span class="Comment"># the number of spaces at the start of the line containing 'curr'.</span>
-<span class="muRecipe">recipe</span> line-indent [
+<span class="muRecipe">recipe</span> line-indent curr:address:duplex-list:character, start:address:duplex-list:character<span class="muRecipe"> -&gt; </span>result:number [
   <span class="Constant">local-scope</span>
-  curr:address:duplex-list<span class="Special"> &lt;- </span><span class="Constant">next-ingredient</span>
-  start:address:duplex-list<span class="Special"> &lt;- </span><span class="Constant">next-ingredient</span>
+  <span class="Constant">load-ingredients</span>
   result:number<span class="Special"> &lt;- </span>copy <span class="Constant">0</span>
-  <span class="muControl">reply-unless</span> curr, result
+  <span class="muControl">reply-unless</span> curr
   at-start?:boolean<span class="Special"> &lt;- </span>equal curr, start
-  <span class="muControl">reply-if</span> at-start?, result
+  <span class="muControl">reply-if</span> at-start?
   <span class="Delimiter">{</span>
     curr<span class="Special"> &lt;- </span>prev-duplex curr
     <span class="muControl">break-unless</span> curr
@@ -934,19 +925,18 @@ body { font-family: monospace; color: #eeeeee; background-color: #080808; }
     <span class="Delimiter">}</span>
     <span class="muControl">loop</span>
   <span class="Delimiter">}</span>
-  <span class="muControl">reply</span> result
 ]
 
 <span class="muScenario">scenario</span> editor-moves-cursor-down-after-inserting-newline-2 [
   assume-screen <span class="Constant">10/width</span>, <span class="Constant">5/height</span>
   <span class="Constant">1</span>:address:array:character<span class="Special"> &lt;- </span>new <span class="Constant">[abc]</span>
-  <span class="Constant">2</span>:address:editor-data<span class="Special"> &lt;- </span>new-editor <span class="Constant">1</span>:address:array:character, screen:address, <span class="Constant">1/left</span>, <span class="Constant">10/right</span>
+  <span class="Constant">2</span>:address:editor-data<span class="Special"> &lt;- </span>new-editor <span class="Constant">1</span>:address:array:character, screen:address:screen, <span class="Constant">1/left</span>, <span class="Constant">10/right</span>
   assume-console [
     type <span class="Constant">[0</span>
 <span class="Constant">1]</span>
   ]
   run [
-    editor-event-loop screen:address, console:address, <span class="Constant">2</span>:address:editor-data
+    editor-event-loop screen:address:screen, console:address:console, <span class="Constant">2</span>:address:editor-data
   ]
   screen-should-contain [
    <span class="Constant"> .          .</span>
@@ -960,7 +950,7 @@ body { font-family: monospace; color: #eeeeee; background-color: #080808; }
 <span class="muScenario">scenario</span> editor-clears-previous-line-completely-after-inserting-newline [
   assume-screen <span class="Constant">10/width</span>, <span class="Constant">5/height</span>
   <span class="Constant">1</span>:address:array:character<span class="Special"> &lt;- </span>new <span class="Constant">[abcde]</span>
-  <span class="Constant">2</span>:address:editor-data<span class="Special"> &lt;- </span>new-editor <span class="Constant">1</span>:address:array:character, screen:address, <span class="Constant">0/left</span>, <span class="Constant">5/right</span>
+  <span class="Constant">2</span>:address:editor-data<span class="Special"> &lt;- </span>new-editor <span class="Constant">1</span>:address:array:character, screen:address:screen, <span class="Constant">0/left</span>, <span class="Constant">5/right</span>
   assume-console [
     press enter
   ]
@@ -972,7 +962,7 @@ body { font-family: monospace; color: #eeeeee; background-color: #080808; }
    <span class="Constant"> .          .</span>
   ]
   run [
-    editor-event-loop screen:address, console:address, <span class="Constant">2</span>:address:editor-data
+    editor-event-loop screen:address:screen, console:address:console, <span class="Constant">2</span>:address:editor-data
   ]
   <span class="Comment"># line should be fully cleared</span>
   screen-should-contain [
@@ -989,7 +979,7 @@ body { font-family: monospace; color: #eeeeee; background-color: #080808; }
   <span class="Constant">1</span>:address:array:character<span class="Special"> &lt;- </span>new <span class="Constant">[ab</span>
 <span class="Constant">  cd</span>
 <span class="Constant">ef]</span>
-  <span class="Constant">2</span>:address:editor-data<span class="Special"> &lt;- </span>new-editor <span class="Constant">1</span>:address:array:character, screen:address, <span class="Constant">0/left</span>, <span class="Constant">10/right</span>
+  <span class="Constant">2</span>:address:editor-data<span class="Special"> &lt;- </span>new-editor <span class="Constant">1</span>:address:array:character, screen:address:screen, <span class="Constant">0/left</span>, <span class="Constant">10/right</span>
   <span class="Comment"># position cursor after 'cd' and hit 'newline'</span>
   assume-console [
     left-click <span class="Constant">2</span>, <span class="Constant">8</span>
@@ -997,7 +987,7 @@ body { font-family: monospace; color: #eeeeee; background-color: #080808; }
 ]
   ]
   run [
-    editor-event-loop screen:address, console:address, <span class="Constant">2</span>:address:editor-data
+    editor-event-loop screen:address:screen, console:address:console, <span class="Constant">2</span>:address:editor-data
     <span class="Constant">3</span>:number<span class="Special"> &lt;- </span>get *<span class="Constant">2</span>:address:editor-data, <span class="Constant">cursor-row:offset</span>
     <span class="Constant">4</span>:number<span class="Special"> &lt;- </span>get *<span class="Constant">2</span>:address:editor-data, <span class="Constant">cursor-column:offset</span>
   ]
@@ -1013,7 +1003,7 @@ body { font-family: monospace; color: #eeeeee; background-color: #080808; }
   <span class="Constant">1</span>:address:array:character<span class="Special"> &lt;- </span>new <span class="Constant">[ab</span>
 <span class="Constant">  cd</span>
 <span class="Constant">ef]</span>
-  <span class="Constant">2</span>:address:editor-data<span class="Special"> &lt;- </span>new-editor <span class="Constant">1</span>:address:array:character, screen:address, <span class="Constant">0/left</span>, <span class="Constant">10/right</span>
+  <span class="Constant">2</span>:address:editor-data<span class="Special"> &lt;- </span>new-editor <span class="Constant">1</span>:address:array:character, screen:address:screen, <span class="Constant">0/left</span>, <span class="Constant">10/right</span>
   <span class="Comment"># position cursor after 'cd' and hit 'newline' surrounded by paste markers</span>
   assume-console [
     left-click <span class="Constant">2</span>, <span class="Constant">8</span>
@@ -1022,7 +1012,7 @@ body { font-family: monospace; color: #eeeeee; background-color: #080808; }
     press <span class="Constant">65506</span>  <span class="Comment"># end paste</span>
   ]
   run [
-    editor-event-loop screen:address, console:address, <span class="Constant">2</span>:address:editor-data
+    editor-event-loop screen:address:screen, console:address:console, <span class="Constant">2</span>:address:editor-data
     <span class="Constant">3</span>:number<span class="Special"> &lt;- </span>get *<span class="Constant">2</span>:address:editor-data, <span class="Constant">cursor-row:offset</span>
     <span class="Constant">4</span>:number<span class="Special"> &lt;- </span>get *<span class="Constant">2</span>:address:editor-data, <span class="Constant">cursor-column:offset</span>
   ]
@@ -1039,7 +1029,8 @@ body { font-family: monospace; color: #eeeeee; background-color: #080808; }
     <span class="muControl">break-unless</span> paste-start?
     indent?:address:boolean<span class="Special"> &lt;- </span>get-address *editor, <span class="Constant">indent?:offset</span>
     *indent?<span class="Special"> &lt;- </span>copy <span class="Constant">0/false</span>
-    <span class="muControl">reply</span> screen/same-as-ingredient:<span class="Constant">0</span>, editor/same-as-ingredient:<span class="Constant">1</span>, <span class="Constant">1/go-render</span>
+    go-render?<span class="Special"> &lt;- </span>copy <span class="Constant">1/true</span>
+    <span class="muControl">reply</span>
   <span class="Delimiter">}</span>
 ]
 
@@ -1049,18 +1040,16 @@ body { font-family: monospace; color: #eeeeee; background-color: #080808; }
     <span class="muControl">break-unless</span> paste-end?
     indent?:address:boolean<span class="Special"> &lt;- </span>get-address *editor, <span class="Constant">indent?:offset</span>
     *indent?<span class="Special"> &lt;- </span>copy <span class="Constant">1/true</span>
-    <span class="muControl">reply</span> screen/same-as-ingredient:<span class="Constant">0</span>, editor/same-as-ingredient:<span class="Constant">1</span>, <span class="Constant">1/go-render</span>
+    go-render?<span class="Special"> &lt;- </span>copy <span class="Constant">1/true</span>
+    <span class="muControl">reply</span>
   <span class="Delimiter">}</span>
 ]
 
 <span class="SalientComment">## helpers</span>
 
-<span class="muRecipe">recipe</span> draw-horizontal [
+<span class="muRecipe">recipe</span> draw-horizontal screen:address:screen, row:number, x:number, right:number [
   <span class="Constant">local-scope</span>
-  screen:address<span class="Special"> &lt;- </span><span class="Constant">next-ingredient</span>
-  row:number<span class="Special"> &lt;- </span><span class="Constant">next-ingredient</span>
-  x:number<span class="Special"> &lt;- </span><span class="Constant">next-ingredient</span>
-  right:number<span class="Special"> &lt;- </span><span class="Constant">next-ingredient</span>
+  <span class="Constant">load-ingredients</span>
   style:character, style-found?:boolean<span class="Special"> &lt;- </span><span class="Constant">next-ingredient</span>
   <span class="Delimiter">{</span>
     <span class="muControl">break-if</span> style-found?